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Offenhauser VS Clifford

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vcbota
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Offenhauser VS Clifford

Post #1 by vcbota » Thu Aug 06, 2020 5:31 pm

Dual-port Offenhauser with a Holley Sniper or Clifford dual Weber 38 kit for low-end torque on a 300 with 240 heads town/mountain 71 Bronco with an NP 435/205 and 35s? Both are the same price.

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Re: Offenhauser VS Clifford

Post #2 by vcbota » Thu Aug 06, 2020 5:38 pm

What about the Clifford manifold with Holley 2 bbl snipers?

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Re: Offenhauser VS Clifford

Post #3 by pmuller9 » Thu Aug 06, 2020 8:36 pm

Offenhauser "C" with Holley 2 bbl sniper.
https://www.ford-trucks.com/forums/1557 ... st18225044

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Re: Offenhauser VS Clifford

Post #4 by vcbota » Thu Aug 06, 2020 9:43 pm

The "C" is for higher RPM, my truck is a mountain/ town / rock truck, I live below 3000 RPM, and under 55 MPH, it needs stable and solid low rpm drive with a lot of low-end torque. The idea for the dual-plane intake and or the two carbs or EFIs set up was to make sure all pistons would equally fire on low RPM and inclines, and quickly starts in cold weather, I'm NY going up the mountains. And I love the nostalgic hot rod look and feel of two carbs. I'm redoing the whole truck, so it would be great to look and perform like a vintage safari forest hotrod truck.

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Re: Offenhauser VS Clifford

Post #5 by THE FRENCHTOWN FLYER » Thu Aug 06, 2020 9:58 pm

Use the lower half of an EFI intake and fab the upper for an equal length runner intake tuned for lower rpm. Two YFs would probably work well.
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Re: Offenhauser VS Clifford

Post #6 by bubba22349 » Thu Aug 06, 2020 10:20 pm

If you wanted that Vintage Hot Rod look there's always FTF's Triple 1V carb intake for that kind of pure Nostalgia. There's an article by FTF about building his 3 X 1V Intake over on the Inliners International site showing how he built it using 3 stock Ford 1V intakes has lots pictures showing the process. It's Pure Genius and its almost like Ford planed ahead for this project to be done, see link below. I wonder if you couldn't also make a 2 X 1V intake in the same way just by cutting in a few different locations would also be a good experiment. Good luck on your Bronco. :thumbup: :nod:

Ford 300 3x1 intake fabrication
Even a bad day Drag Racing is still better than a good day at work!

Current project is a 1988 John Deere 420 Garden Tractor I need a few small parts to get it fixed, plus some cosmetic items, maybe a few attachments, if you happen to have or know of JD 420 parts would welcome the help!

My Ex-Inline 6 Fleet 1954 Customline 223 3 speed with O/D, 1963 Fairlane project drag car with BB6, 1977 Maverick 250 with C4, 1994 F-150 a 300 with 5 speed.

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Re: Offenhauser VS Clifford

Post #7 by vcbota » Fri Aug 07, 2020 12:26 am

One of my ideas was to use the lower part EFI intake with three Weber 40 IDF; then, I found that Clifford used to make something similar, link below. I asked them for one. They said, "We do not cast this intake any longer because it needs 12:1 compression. Too much for the street, and they are very hard to keep tuned. They are direct port as well, causing poor atomization." The carb over the Snipers for a hotrod look, but the EFI is better in cold weather, mpg, and off-road, but the EFI will cost more also. After all, it is not my daily driving car. I live in NYC.

viewtopic.php?t=76975#top

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Re: Offenhauser VS Clifford

Post #8 by sdiesel » Fri Aug 07, 2020 12:29 am

Crazy reliable would have to be a modern efi setup.
Manifold? There is little question that aussiespeed is far and away the very coolest on the market.
I like the Clifford for the hot water chambers do not like it for its goofy mounting pattern, and oddball thread on its water box.
The offy is ugly.

If carb, there are but one option based on your stated usage
The q jet. Who can argue that a better carb ?
Or the FISH. Which of course is ridiculous, as its nearly unobtainable and it has no choke. But has a low , and high range throttle response unmatched even I would say by The modern t body units, but I cannot be unequivocal in that.
Last best option for that kind of rig...propane, a 300 or 425 mixer, model e converter a kill switch and tank, and you will have a fine unit
a long love affair with the 300 six.
my lastest and final fling is a fresh 300 in an 88 ford f350 dually 4X flatbed

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Re: Offenhauser VS Clifford

Post #9 by 1986F150six » Fri Aug 07, 2020 10:59 am

If interested in a never installed Clifford 2X4 intake manifold, PM me.

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Re: Offenhauser VS Clifford

Post #10 by jgregg13 » Fri Aug 07, 2020 2:37 pm

Seems to me if you want nostalgic hot roddy look and good grunt, a 471 blower with a Q-jet on top should do it. Aussiespeed might have a blower manifold or just put a plate on a 4bbl manifold and add a blow off plate to the bottom. Use EFI exhaust manifolds with full duals and you've got it all, rappin', blower whine, grunt. What more is there?

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Re: Offenhauser VS Clifford

Post #11 by vcbota » Fri Aug 07, 2020 4:35 pm

That was my first idea, I even spoke with Aussiespeed, they are making a manifold for it but still not ready, and going off-road with a blower concerns me a bit, mud, snow, and rain of NY mountains ay create some issues. It also won't fit under the hood on the early Bronco; I even have to change to serpentine pulleys to mount the radiator inside the engine bay; it is on the back now.

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Re: Offenhauser VS Clifford

Post #12 by vcbota » Fri Aug 07, 2020 4:41 pm

Are the EFI exhaust manifolds are better than headers long or short?

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Re: Offenhauser VS Clifford

Post #13 by pmuller9 » Fri Aug 07, 2020 5:35 pm

vcbota wrote:Are the EFI exhaust manifolds are better than headers long or short?

There are torque improvements at all rpms with the long tube headers made for the 300 six.
The problem with a long header is starter access, heat and bad ground clearance for off road use.
The EFI exhaust does well enough and is far more rugged than a header be it short or long.

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Re: Offenhauser VS Clifford

Post #14 by BigBlue94 » Fri Aug 07, 2020 6:27 pm

pmuller9 wrote:
vcbota wrote:Are the EFI exhaust manifolds are better than headers long or short?

There are torque improvements at all rpms with the long tube headers made for the 300 six.
The problem with a long header is starter access, heat and bad ground clearance for off road use.
The EFI exhaust does well enough and is far more rugged than a header be it short or long.


I have zero issues with clearance for off road purposes with my clifford long tubes. They do not drop past the frame at any point.

Heat is an issue when only moving slowly. At 30+ mph, its no issue. But crawling offroad, whoo boy my engine got up to 240°.
1985 Bronco. 309ci I6, NP435, 4.56 gears, Detroit locker and tru-trac, 4" lift, and 37" swamper tires. The 309 is 9.75:1 CR with a Schneider 140H cam, 4bbl, roller rockers, larger valves, and headers.

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Re: Offenhauser VS Clifford

Post #15 by vcbota » Fri Aug 07, 2020 6:51 pm

Below is my original plan. The option is Offenhauser dual palce or Aussiespeed intake with a Brawler Black Street Series, 680 cfm (reviews say that 600 is not enough for low rpm), or Holley Sniper, and EFI exhaust manifold.

• Davis Unified HEI Distributor / 10 mm cables
• ATK 2F03 cylinder heads 240 heads
• Headwork
o Polish the tops of the valves and mill .060 off cylinder head.
o Replace the studs with screw-in studs. 7/16 into the boss and 3/8 for the rocker arms.
• Cam kit https://cliffordperformance.net/store/o ... am-and-kit
• Top end kit https://cliffordperformance.net/store/o ... m-wheaders
• Harland Sharp roller rocker 1.6

On an NP 435/205 with 3.73 and 35s

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Re: Offenhauser VS Clifford

Post #16 by sdiesel » Fri Aug 07, 2020 7:24 pm

That seems a less expensive way around this rock in the road.
But u do want dual carbs , even though an efi of modern vintage is in every measurable way, a better route, and likely cheaper.
A q jet better performance at every level than two weber, ( I believe).

Efi exhausts rocks especially with ceramic coat inside. Avoid the walker y pipe. Build one. A fella on here has a gorgeous example of one he built that is in everyway superior to anything u can buy, but I've forgotten his name.
There are 8 thousand options for cam. Muller mentions several from many different sources that are quite affordable. Schneider 140 comes to mind.


Ford's dspark 111, is a very good system and dirt cheap, and looks better. And can use the hei module or MSD VERY REadily. Urging caution with water and msd box.

Most definitely plan on upgrading the alternator to a 3G version. Its bolt in for the six,
a long love affair with the 300 six.
my lastest and final fling is a fresh 300 in an 88 ford f350 dually 4X flatbed

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Re: Offenhauser VS Clifford

Post #17 by pmuller9 » Fri Aug 07, 2020 9:09 pm

vcbota wrote:• ATK 2F03 cylinder heads 240 heads
• Headwork
o Polish the tops of the valves and mill .060 off cylinder head.
o Replace the studs with screw-in studs. 7/16 into the boss and 3/8 for the rocker arms.

Do not mill .060" off the 240 cylinder head.
The 240 head alone will raise the compression ratio to a sufficient level for pump gas with a 264 degree cam.

I personally would rework the 1971 head with bigger valves and port work with screw in studs. Save a bunch of money.
With bigger valves the 300 carb head will outflow the 240 head because of the valve shrouding unless you take the time to modify the 240 head combustion chambers.

With the stock compression ratio you can advance the cam 4 degrees in order to make plenty of low end torque and be able to use any octane pump gas.

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Re: Offenhauser VS Clifford

Post #18 by vcbota » Sat Aug 08, 2020 2:09 am

Now I have more questions than answers. LOL

The 240 head is the only thing I already have, I thought about putting bigger valves, SI 4.810” Ford 1.94”/1.60” valves.
I would like to be at 9.5:1 CR. With the 240 head, I will be around 8.7:1 it is a 79 low CR out of an F150, not a 71, the 240 head is 68~72.

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Re: Offenhauser VS Clifford

Post #19 by pmuller9 » Sat Aug 08, 2020 8:16 am

Based on the history of the many 300 six builds on this site the Dynamic Compression Ratio (DCR) range for 87 to 93 octane pump gas is 7.0 to 7.5
The DCR is calculated using the intake valve closing point ABDC using the cam's advertised duration.

The stock cam has an advertised duration of 268 degrees and is installed 4 degrees retarded with the intake lobe center at 114 degrees ATDC. The intake valve closing point is at 68 degrees ABDC
With an 8.8:1 Static Compression Ratio (SCR) the DCR is 6.9 leaving some margin for 87 octane pump gas.

The Clifford 264 cam has an advertised duration of 264 degrees and if it is installed 4 degrees advanced (cam card spec) with the intake lobe center at 106 degrees ATDC the intake valve closing point is 58 degrees ABDC and the DCR is now 7.4 using the same 8.8 SCR.
If you go much higher on the SCR you will have a problem getting the engine to run on pump gas without detonation.

The Bronco's on this site running between a 9.0 to 9.75 SCR are using cams with advertised durations in the 280 degree range and are doing their off road work at high elevations.

If you are doing rock climbing and need torque at idle then yes you need a low duration cam and the compression ratio must be kept low to accommodate.

vcbota wrote:The "C" is for higher RPM, my truck is a mountain/ town / rock truck, I live below 3000 RPM, and under 55 MPH, it needs stable and solid low rpm drive with a lot of low-end torque.

I missed this earlier.
If you don't need power above 3000 rpm then there is no need to go with bigger valves.
Just do the port work with most of the attention in the bowl area.

I would use the stock cam with the 1.75 ratio Harland Sharp roller rockers. (S3002)
Crower makes a "rock crawler" cam but it needs a compression ratio closer to 8:1.
248HDP (19210) .405”/.411” 184/192 248/254 112deg


Are you going to rebuild the 79 short block or use the stock pistons as is?

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Re: Offenhauser VS Clifford

Post #20 by BigBlue94 » Sat Aug 08, 2020 11:38 am

680 cfm is way to much carb for under 10:1 compression. Im running 9.75 SCR and 7.47 DCR with a 450 cfm. It is plenty.
1985 Bronco. 309ci I6, NP435, 4.56 gears, Detroit locker and tru-trac, 4" lift, and 37" swamper tires. The 309 is 9.75:1 CR with a Schneider 140H cam, 4bbl, roller rockers, larger valves, and headers.

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Re: Offenhauser VS Clifford

Post #21 by vcbota » Sat Aug 08, 2020 12:58 pm

I wasn't planning on doing the short the block unless it is needed as I open it.

Attention to what when porting the in the bowl area?

The stock cam specs are 1.6, would 1.75 rockers work with it?

I will run it on 91~93 octane, or even E85 if it is needed. I live in NYC so it is a weekend, off-road, beach vehicle.

My goal is to get close to 400lb torque. Clifford said that with he kits, polishing the valves, and milling the 240 head, I would be around 360. They also said that If I do not need high RPM, I do not need roller rockers, the stock ones out of the 300 head will do.

I was also reading some text and the Holey Sniper against carb; the gain was extremely minimal. I wish Aussipeedor Offy had a dual or triple set up intake, and coming all together makes the Clifforset up much easier, and I like the way it looks. The cylinders are so apart from that one single quad has a hard time sending fuel equally, the ones the middle such most of it right away, its physics, that's EFI injects every cylinder.

I would love to have the Aussie long runners with a carb stack. I was even thinking of using the EFI intake and putting the carbs on the other side. EFI intake is set like that to give more low-end power.

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Re: Offenhauser VS Clifford

Post #22 by vcbota » Sat Aug 08, 2020 1:16 pm

How do I post pictures here?

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Re: Offenhauser VS Clifford

Post #23 by pmuller9 » Sat Aug 08, 2020 7:12 pm

vcbota wrote:How do I post pictures here?


Upload your pictures to a host site like imgbb.com or dropbox.
Then copy the photo link between the [image][/image] from the above tool bar that you see when in the edit mode.

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Re: Offenhauser VS Clifford

Post #24 by pmuller9 » Sat Aug 08, 2020 7:23 pm

vcbota wrote:Attention to what when porting the in the bowl area?

In order to get maximum torque the restriction to airflow around the valve guide boss must be minimized.
Here is a mild approach to the intake bowl
Image

Here is a more radical approach combined with undercut valve stems.
Image

Here is the exhaust port and bowl.
Image

Complete the job by doing a 30 degree back cut on the valve head just after the 45 degree seat contact area.

Image

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Re: Offenhauser VS Clifford

Post #25 by pmuller9 » Sat Aug 08, 2020 8:15 pm

It is a very common practice here to use the Chevy six 1.75 ratio rocker arms with the stock Ford six cam to increase the valve lift.

If you are willing to run whatever fuel octane to meet a higher compression ratio then milling the head is fine.
I would wait until you inspect the cylinder wear. If you need oversize pistons then you can make up the compression with pistons and block deck machining.

If you want a double or triple carb set-up then use the lower half of the EFI intake and make your own plenum and carburetor mounting plate.
The long and equal length runners are a better configuration than the Clifford intake for low rpm response.

Image

Don't forget that a TBI or EFI doesn't care what angle the vehicle is at while climbing. A carburetor does.
Last edited by pmuller9 on Sat Aug 08, 2020 8:52 pm, edited 1 time in total.

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Re: Offenhauser VS Clifford

Post #26 by pmuller9 » Sat Aug 08, 2020 8:46 pm

As far as ignition the most low rpm torque is found by using the MSD 6A or 6AL with the Ford Duraspark distributor.
There are many that have used this combination including myself and every one will tell you the same story.
The idle and low rpm response is better than with the previous ignition it replaced.

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Re: Offenhauser VS Clifford

Post #27 by vcbota » Sat Aug 08, 2020 9:22 pm

Do you know the stock numbers for the 4.9? I've trying to find what are the stock dome volume, gasket, deck clearance, etc. But I can't find it anywhere.

What is the max CR the 4.9 with the 240 iron heads can handle 91 and 93 octane before it starts to pin?

If I mill the 240 .060 and use Fel Pro #1024 gasket

I will make an intake like and want to put Webber 48 stack, but until them, I very inclined towards Clifford's dual Webber 38. As of cam I'm still divided,

if the short block needs works, then it changes, I will put piston to reach it.

Before deciding to stay on the 4.9, I planned to do a roller 351W with 10.5:1 CR for it. One of the main reasons I stayed with the 4.9 was the nostalgic look with carb stack; I have the 351 ready to go. The cost is about the same, the 351 would cost 1K more, and it is a generic setup.

BTW: the 351 came out of a 97 F350 with an E4OD, which works well but it is too big for my Bronco, if anyone needs it, it's justing sitting in storage there.





pmuller9 wrote:It is a very common practice here to use the Chevy six 1.75 ratio rocker arms with the stock Ford six cam to increase the valve lift.

If you are willing to run whatever fuel octane to meet a higher compression ratio then milling the head is fine.
I would wait until you inspect the cylinder wear. If you need oversize pistons then you can make up the compression with pistons and block deck machining.

If you want a double or triple carb set-up then use the lower half of the EFI intake and make your own plenum and carburetor mounting plate.
The long and equal length runners are a better configuration than the Clifford intake for low rpm response.

Image

Don't forget that a TBI or EFI doesn't care what angle the vehicle is at while climbing. A carburetor does.

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Re: Offenhauser VS Clifford

Post #28 by vcbota » Sat Aug 08, 2020 9:25 pm

I'm putting Davis Unified HEI Distributor / 10 mm cables / Ignition box, and a 6G alternator

What is better the 6A or 6L?



pmuller9 wrote:As far as ignition the most low rpm torque is found by using the MSD 6A or 6AL with the Ford Duraspark distributor.
There are many that have used this combination including myself and every one will tell you the same story.
The idle and low rpm response is better than with the previous ignition it replaced.

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Re: Offenhauser VS Clifford

Post #29 by pmuller9 » Sat Aug 08, 2020 10:10 pm

The stock piston for the 79 4.9 has a 19 cc round dish that is off center.
The piston has a .037" deck clearance.
The cylinder head combustion chamber has a 76cc volume.
A Fel-Pro 1024 gasket has a 4.18" bore and a .039" compressed thickness.
Compression ratio with a 4.00" bore is 8.56

The 240 head has a 68 cc chamber and would increase the compression ratio to 9.16

If you milled about .050" off the head the chamber volume should be about 64 cc which would raise the compression ratio to 9.5

As I explained previously the max Static Compression Ratio depends on the camshaft's intake valve closing point.
The intake valve closing point versus the static compression ratio determines the Dynamic Compression Ratio
The Max Dynamic Compression ratio is 7.5 at sea level for 91 to 93 octane pump gas.
Last edited by pmuller9 on Sat Aug 08, 2020 10:52 pm, edited 1 time in total.

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Re: Offenhauser VS Clifford

Post #30 by pmuller9 » Sat Aug 08, 2020 10:22 pm

The HEI ignition system is not a good match for a low rpm operating range.
It has a very low primary resistance coil for good spark at high rpm operations.
At very low rpm the HEI module has to current regulate the primary coil current for a long dwell period which means the module has to dissipate a lot of energy in the form of heat.

The MSD 6AL has a rev limiter and has a little more spark energy than the 6A which doesn't have a rev limiter.

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Re: Offenhauser VS Clifford

Post #31 by vcbota » Sat Aug 08, 2020 11:35 pm

What about the Davis United Ignition D.U.I. distributors ?

pmuller9 wrote:The HEI ignition system is not a good match for a low rpm operating range.
It has a very low primary resistance coil for good spark at high rpm operations.
At very low rpm the HEI module has to current regulate the primary coil current for a long dwell period which means the module has to dissipate a lot of energy in the form of heat.

The MSD 6AL has a rev limiter and has a little more spark energy than the 6A which doesn't have a rev limiter.

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Re: Offenhauser VS Clifford

Post #32 by pmuller9 » Sun Aug 09, 2020 12:30 am

vcbota wrote:What about the Davis United Ignition D.U.I. distributors ?

pmuller9 wrote:The HEI ignition system is not a good match for a low rpm operating range.
It has a very low primary resistance coil for good spark at high rpm operations.
At very low rpm the HEI module has to current regulate the primary coil current for a long dwell period which means the module has to dissipate a lot of energy in the form of heat.


The D.U.I. distributor uses the Dyna-Module which has even a longer dwell time than the stock HEI module.
Good for high rpm spark but runs hot at extended very low rpm.

The MSD has better spark intensity and provides multiple sparks at low rpm.
We have found the MSD to produce the best low rpm torque of all the ignition systems for the Ford 4.9.

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Re: Offenhauser VS Clifford

Post #33 by vcbota » Sun Aug 09, 2020 1:38 am

What about a PerTronix Second Strike Ignition Box or a Digital HP?
DIS system?
What do you recommend?

I want to put as much fire as possible into the cylinders.





pmuller9 wrote:
vcbota wrote:What about the Davis United Ignition D.U.I. distributors ?

pmuller9 wrote:The HEI ignition system is not a good match for a low rpm operating range.
It has a very low primary resistance coil for good spark at high rpm operations.
At very low rpm the HEI module has to current regulate the primary coil current for a long dwell period which means the module has to dissipate a lot of energy in the form of heat.


The D.U.I. distributor uses the Dyna-Module which has even a longer dwell time than the stock HEI module.
Good for high rpm spark but runs hot at extended very low rpm.

The MSD has better spark intensity and provides multiple sparks at low rpm.
We have found the MSD to produce the best low rpm torque of all the ignition systems for the Ford 4.9.

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Re: Offenhauser VS Clifford

Post #34 by vcbota » Sun Aug 09, 2020 1:40 am

What do you recommend to go with Clifford's dual 38s for the most torque possible on 91~93 octane?




pmuller9 wrote:The stock piston for the 79 4.9 has a 19 cc round dish that is off center.
The piston has a .037" deck clearance.
The cylinder head combustion chamber has a 76cc volume.
A Fel-Pro 1024 gasket has a 4.18" bore and a .039" compressed thickness.
Compression ratio with a 4.00" bore is 8.56

The 240 head has a 68 cc chamber and would increase the compression ratio to 9.16

If you milled about .050" off the head the chamber volume should be about 64 cc which would raise the compression ratio to 9.5

As I explained previously the max Static Compression Ratio depends on the camshaft's intake valve closing point.
The intake valve closing point versus the static compression ratio determines the Dynamic Compression Ratio
The Max Dynamic Compression ratio is 7.5 at sea level for 91 to 93 octane pump gas.

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Re: Offenhauser VS Clifford

Post #35 by vcbota » Sun Aug 09, 2020 1:41 am

I already have the 240 heads.

vcbota wrote:What do you recommend to go with Clifford's dual 38s for the most torque possible on 91~93 octane?




pmuller9 wrote:The stock piston for the 79 4.9 has a 19 cc round dish that is off center.
The piston has a .037" deck clearance.
The cylinder head combustion chamber has a 76cc volume.
A Fel-Pro 1024 gasket has a 4.18" bore and a .039" compressed thickness.
Compression ratio with a 4.00" bore is 8.56

The 240 head has a 68 cc chamber and would increase the compression ratio to 9.16

If you milled about .050" off the head the chamber volume should be about 64 cc which would raise the compression ratio to 9.5

As I explained previously the max Static Compression Ratio depends on the camshaft's intake valve closing point.
The intake valve closing point versus the static compression ratio determines the Dynamic Compression Ratio
The Max Dynamic Compression ratio is 7.5 at sea level for 91 to 93 octane pump gas.

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Re: Offenhauser VS Clifford

Post #36 by pmuller9 » Sun Aug 09, 2020 9:44 am

vcbota wrote:What about a PerTronix Second Strike Ignition Box or a Digital HP?
DIS system?
What do you recommend?

I want to put as much fire as possible into the cylinders.

The object is to stay away from inductive discharge ignitions that do not have dwell control.
The reason is at low rpm (where you be operating all the time) the ignition coil is charged and then spends the remaining long dwell period in saturation waiting for the discharge moment.
During the wasted long saturation period the coil is heated as well as the unit driving the coil and spark energy decreases.

The MSD is a capacitive discharge system where the charged capacitor discharges all of it's energy into the coil and produces a spark current much higher than the inductive discharge systems.
It also provides multiple sparks below 3000 rpm.
The coil never sees a saturation period so it runs cooler.

The PerTronix Second Strike uses an inductive spark then follows it up with a capacitive discharge spark.
You really want to lead with the high intensity CD spark.

The Digital HP is a single spark unit. Since the MSD only provides multi-spark up to 3000 rpm they figured most V8 power users are looking for power above that point so why bother with a multi-spark.
You are working below 3000 rpm and the multi-spark feature of the MSD works well for low rpm torque.

I recommend the MSD 6AL with a Duraspark2 distributor that has been recurved by "wsa111" one of the members here.

vcbota wrote:What do you recommend to go with Clifford's dual 38s for the most torque possible on 91~93 octane?

We don't have experience with the Weber carbs as far as I know but I'm sure they would do just fine.

What we do know from experience is the Autolite/Motorcraft 2100/2150 are excellent carburetors and do a great job with fuel atomization since they have Annular Fuel Discharge.

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Re: Offenhauser VS Clifford

Post #37 by BigBlue94 » Sun Aug 09, 2020 2:36 pm

Im running the Davis Unified Ignition HEI. Their livewires didnt fit, and i still have em somewhere. They just arent long enough. Great construction and insulation though.

Before that i was running a points distributor with a pertronix conversion in it and 50ohm wires. Was also a great little setup.

As far as issues at low rpm, I have no issues with power. But like paul said, it really screams at higher rpm.

Im at 9.75:1 static and 7.47:1 dynamic. Runs well at 1000' on 89 octane. Runs well at 5000' on 87 octane.
1985 Bronco. 309ci I6, NP435, 4.56 gears, Detroit locker and tru-trac, 4" lift, and 37" swamper tires. The 309 is 9.75:1 CR with a Schneider 140H cam, 4bbl, roller rockers, larger valves, and headers.

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Re: Offenhauser VS Clifford

Post #38 by vcbota » Sun Aug 09, 2020 3:09 pm

I will reach out to Billy. Thank you.

What if I do the Holley Sniper with Aussiepeed intake? I will be the same price; I'm divided between the nostalgic look and the reliability.




pmuller9 wrote:
vcbota wrote:What about a PerTronix Second Strike Ignition Box or a Digital HP?
DIS system?
What do you recommend?

I want to put as much fire as possible into the cylinders.

The object is to stay away from inductive discharge ignitions that do not have dwell control.
The reason is at low rpm (where you be operating all the time) the ignition coil is charged and then spends the remaining long dwell period in saturation waiting for the discharge moment.
During the wasted long saturation period the coil is heated as well as the unit driving the coil and spark energy decreases.

The MSD is a capacitive discharge system where the charged capacitor discharges all of it's energy into the coil and produces a spark current much higher than most of the inductive discharge systems.
It also provides multiple sparks below 3000 rpm.
The coil never sees a saturation period so it runs cooler.

I recommend the MSD 6AL with a Duraspark2 distributor that has been recurved by "wsa111" one of the members here.

vcbota wrote:What do you recommend to go with Clifford's dual 38s for the most torque possible on 91~93 octane?

We don't have experience with the Weber carbs as far as I know but I'm sure they would do just fine.

What we do know from experience is the Autolite/Motorcraft 2100/2150 are excellent carburetors and do a great job with fuel atomization since they have Annular Fuel Discharge.

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Re: Offenhauser VS Clifford

Post #39 by vcbota » Sun Aug 09, 2020 3:12 pm

hahahah

Like I said more questions.

What you be ideal setup for max low end torque running on 91~93?


BigBlue94 wrote:Im running the Davis Unified Ignition HEI. Their livewires didnt fit, and i still have em somewhere. They just arent long enough. Great construction and insulation though.

Before that i was running a points distributor with a pertronix conversion in it and 50ohm wires. Was also a great little setup.

As far as issues at low rpm, I have no issues with power. But like paul said, it really screams at higher rpm.

Im at 9.75:1 static and 7.47:1 dynamic. Runs well at 1000' on 89 octane. Runs well at 5000' on 87 octane.

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Re: Offenhauser VS Clifford

Post #40 by pmuller9 » Sun Aug 09, 2020 4:30 pm

vcbota wrote:I will reach out to Billy. Thank you.

What if I do the Holley Sniper with Aussiepeed intake? I will be the same price; I'm divided between the nostalgic look and the reliability.

You already know the answer. LOL
The Holley Sniper with the long runner Aussiespeed intake will give you great low end torque.
The Holley Sniper is immune to steep climbing angles.
The Holley Sniper 2300 has it's own timing control so you can do your own advance curve.
You can change the timing curve for best results without detonation.
The DS2 distributor's mechanical advance and vacuum advance gets locked.
The locked DS2 then triggers the Sniper and the Sniper will trigger the MSD unit.
Last edited by pmuller9 on Sun Aug 09, 2020 4:58 pm, edited 1 time in total.

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Re: Offenhauser VS Clifford

Post #41 by pmuller9 » Sun Aug 09, 2020 4:53 pm

vcbota wrote:hahahah

Like I said more questions.

What you be ideal setup for max low end torque running on 91~93?

OK A questions for you.
Just for reference: The stock 4.9 makes max torque at 1800 to 2000 rpm and max horsepower at 3000 to 3200 rpm.

If you are looking for huge torque, it requires some engine rpm to create high velocity airflow in the intake system so the cylinders continue to fill well beyond BDC and into the compression cycle. Volumetric Efficiency
Aside from modifications to the cylinder head for better port flow you need a moderate duration, high lift cam similar to the Clifford cam they suggested or a little larger and the highest compression ratio the fuel will allow.
That puts the torque peak around the 2500 rpm range.
Torque at an idle is still good.
The only reason for not going with even a larger cam is that you don't run the engine above 3000 rpm.

If you need tractor power at 600 rpm then the cam must have a very short duration where the intake valve is closed early with relatively high valve lift (This is where the 1.75 ratio rockers are used) but you sacrifice the engines maximum torque numbers.

A side note:
The ultimate set-up is the tractor power at 500 to 600 rpm and a small 49 mm turbocharger that starts making boost just after idle with full 8 to 10 lbs of boost before or at 2000 rpm. Over 500 ft lbs of torque.

What type of power will work the best for you?

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Re: Offenhauser VS Clifford

Post #42 by vcbota » Sun Aug 09, 2020 6:23 pm

Do you still have it? It would be perfect for what I want, I would put two two-barrel snippers on it. Let me know how much you want for it. thunderchief1972@gmail.com

Something like the below but with 2x2.
https://treperformance.com/i-23901955-h ... ramic.html




1986F150six wrote:If interested in a never installed Clifford 2X4 intake manifold, PM me.

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Re: Offenhauser VS Clifford

Post #43 by vcbota » Sun Aug 09, 2020 6:26 pm

You are right but it breaks my heart though, aahah

If can get a Clifford intake than I will put two snippers to have a similar feel and feed all cylinders equally

Is it is self tunning and timing, don't you think that with the EFI the HEI would be fine?


\
pmuller9 wrote:
vcbota wrote:I will reach out to Billy. Thank you.

What if I do the Holley Sniper with Aussiepeed intake? I will be the same price; I'm divided between the nostalgic look and the reliability.

You already know the answer. LOL
The Holley Sniper with the long runner Aussiespeed intake will give you great low end torque.
The Holley Sniper is immune to steep climbing angles.
The Holley Sniper 2300 has it's own timing control so you can do your own advance curve.
You can change the timing curve for best results without detonation.
The DS2 distributor's mechanical advance and vacuum advance gets locked.
The locked DS2 then triggers the Sniper and the Sniper will trigger the MSD unit.

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Re: Offenhauser VS Clifford

Post #44 by vcbota » Sun Aug 09, 2020 6:42 pm

I say low as the mountains around here are always wet and sometimes I have to creep up very slowly not to slide on the wet rock and snow.

Image
Image
Image
Image
Image

pmuller9 wrote:
vcbota wrote:hahahah

Like I said more questions.

What you be ideal setup for max low end torque running on 91~93?

OK A questions for you.
Just for reference: The stock 4.9 makes max torque at 1800 to 2000 rpm and max horsepower at 3000 to 3200 rpm.

If you are looking for huge torque, it requires some engine rpm to create high velocity airflow in the intake system so the cylinders continue to fill well beyond BDC and into the compression cycle. Volumetric Efficiency
Aside from modifications to the cylinder head for better port flow you need a moderate duration, high lift cam similar to the Clifford cam they suggested or a little larger and the highest compression ratio the fuel will allow.
That puts the torque peak around the 2500 rpm range.
Torque at an idle is still good.
The only reason for not going with even a larger cam is that you don't run the engine above 3000 rpm.

If you need tractor power at 600 rpm then the cam must have a very short duration where the intake valve is closed early with relatively high valve lift (This is where the 1.75 ratio rockers are used) but you sacrifice the engines maximum torque numbers.

A side note:
The ultimate set-up is the tractor power at 500 to 600 rpm and a small 49 mm turbocharger that starts making boost just after idle with full 8 to 10 lbs of boost before or at 2000 rpm. Over 500 ft lbs of torque.

What type of power will work the best for you?

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Re: Offenhauser VS Clifford

Post #45 by vcbota » Sun Aug 09, 2020 6:55 pm

I would like to have 350~400lb torque, and I would need to drive around town and be able to keep with small highway traffic ~60mph

Which by guys at Cillford sai that with their kist and the original I would be around 360, but ....

Lats winter I rented a Rubicon Recon and with all its bells and whistles it barely made up, it suffered. It gets slippery and wet with large rocks, snow, and mud.




pmuller9 wrote:
vcbota wrote:hahahah

Like I said more questions.

What you be ideal setup for max low end torque running on 91~93?

OK A questions for you.
Just for reference: The stock 4.9 makes max torque at 1800 to 2000 rpm and max horsepower at 3000 to 3200 rpm.

If you are looking for huge torque, it requires some engine rpm to create high velocity airflow in the intake system so the cylinders continue to fill well beyond BDC and into the compression cycle. Volumetric Efficiency
Aside from modifications to the cylinder head for better port flow you need a moderate duration, high lift cam similar to the Clifford cam they suggested or a little larger and the highest compression ratio the fuel will allow.
That puts the torque peak around the 2500 rpm range.
Torque at an idle is still good.
The only reason for not going with even a larger cam is that you don't run the engine above 3000 rpm.

If you need tractor power at 600 rpm then the cam must have a very short duration where the intake valve is closed early with relatively high valve lift (This is where the 1.75 ratio rockers are used) but you sacrifice the engines maximum torque numbers.

A side note:
The ultimate set-up is the tractor power at 500 to 600 rpm and a small 49 mm turbocharger that starts making boost just after idle with full 8 to 10 lbs of boost before or at 2000 rpm. Over 500 ft lbs of torque.

What type of power will work the best for you?

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Re: Offenhauser VS Clifford

Post #46 by pmuller9 » Sun Aug 09, 2020 9:30 pm

Thanks for the pictures.
They give a much better understanding of the environment.
It looks pretty nasty.

Is having a distributor cap and rotor that can get wet be a problem?

I can safely tell you that 400 ft lbs of torque with an iron head 300 requires forced induction.

If Clifford tells you their kit along with their instructions can yield 360 ft lbs and you trust them then go that direction.

With a 6.68 first gear and 1.97 transfer case (13.1 total gear ratio) the engine response off idle may not be that critical and the focus on torque above 2000 rpm in order to get big numbers may be OK.
You tell me.

What is the differential gear ratio?

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Re: Offenhauser VS Clifford

Post #47 by BigBlue94 » Mon Aug 10, 2020 11:40 am

Seems we have a very similar goal with our engines, but i like to rev mine out. Let me hash out my build for ya.

85 block and head. .060" over for 309ci.

Head- rocker studs installed and harland sharp roller rockers. 1.94 and 1.6 SI valves and bowl work to accommodate them. No port work on the runners. No milling of head surface except to clean it up.

Block- .060" over, zero decked, factory 85 crank and rods. KB 351w Sportsman N pistons- 15cc step dish.

Cam- Schneider 140H with smith bros 3/8" pushrods and guideplates. Hydro lifters.

Intake- clifford single 4bbl, topped by a 450 quickfuel carb. Port matched to head.
Headers and exhaust- clifford 3 into 1 headers, 2.5" y-pipe, 3" cat and muffler.

Bronco- np435/208, 4.56 gears, lockers, 37" tires. No sway bars and a 6" lift.

It has gobs of torque right off idle. It screams up to about 5000 rpm where it becomes gutless. It will do 85 down the highway no problem. And it has no problems getting up to speed or holding it. And when i say itll do it all day, I mean it. Ive done 700 miles over 12 hours at 75mph a couple times.

I dont know what gears you have, but 4.56 would be a really good ratio for you. With 37s, im at about 3000 rpms at 70mph. You would be a couple hundred higher with 35s. 4.10s would give you better milage, but your crawl ratio would suffer. 4.56s give you a 60:1 crawl ratio. 4.10s would give you a 54:1 ratio. With my np208, im at 80:1. I dont even have to press the gas pedal to start moving in granny gear and 4 low. Just let out on the clutch.
1985 Bronco. 309ci I6, NP435, 4.56 gears, Detroit locker and tru-trac, 4" lift, and 37" swamper tires. The 309 is 9.75:1 CR with a Schneider 140H cam, 4bbl, roller rockers, larger valves, and headers.

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Re: Offenhauser VS Clifford

Post #48 by sdiesel » Mon Aug 10, 2020 11:50 pm

Big blue, did you add , or will you add that engine build to the sticky on conceptual builds Pease? It's a popular type of build and reasonably priced to most builders
a long love affair with the 300 six.
my lastest and final fling is a fresh 300 in an 88 ford f350 dually 4X flatbed

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Re: Offenhauser VS Clifford

Post #49 by BigBlue94 » Tue Aug 11, 2020 10:48 am

sdiesel wrote:Big blue, did you add , or will you add that engine build to the sticky on conceptual builds Pease? It's a popular type of build and reasonably priced to most builders


I think its one of the first ones in there but ill double check.

EDIT: yep, its in there, though not as neatly as I put it here. Seems theres only a couple builds in that thread...
1985 Bronco. 309ci I6, NP435, 4.56 gears, Detroit locker and tru-trac, 4" lift, and 37" swamper tires. The 309 is 9.75:1 CR with a Schneider 140H cam, 4bbl, roller rockers, larger valves, and headers.

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Re: Offenhauser VS Clifford

Post #50 by sdiesel » Tue Aug 11, 2020 5:54 pm

Thx fer this
It helps a lot to keep the info in one place
a long love affair with the 300 six.
my lastest and final fling is a fresh 300 in an 88 ford f350 dually 4X flatbed

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