Fresh Rebuilt 240

[sandboxer]

Confirmed. The deep breath helped.

[sandboxer]

Here are a few soldiers...
1987 300
1966 240
1988 300 industrial
1974 240

I’ll figure something out.

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[pmuller9]

Nice collection.
Do you want a high rev 240 or a 300 with a much wider power band and more torque?

Secondly you need to decide if the engine is going to be turbocharged or naturally aspirated.
The compression ratios are very different between those two choices.

There are different size H1C turbos and most are too small for a 240/300 six with a ported head and big cam.
The other problem is the small turbine housing will choke the engine at higher rpm.

The M90 is way too small for a 300. Even an M112 is marginal.

[sandboxer]

Thanks!
I’ll do an NA and a Turbo.

The Clifford dual intake shrunk something fierce during cooling. I’m making my own manifolds with Lunatic Fringe’s AWESOME flanges.

The Turbo is an 18.5/52mm

The Sioux valve and seat grinding outfit matches the rotary phone...ready for head work:)

I’ll do a 240 and a 300. Not sure which gets what. Turbo for the high revving 240? Ideas?

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[pmuller9]

You have the larger H1C with the 8 blade compressor.
The compressor wheel inducer should measure 54mm.
You can measure the inlet diameter to verify.
If you measure a 54mm inlet then the turbocharger can make 400 hp without straining.

The turbine has a T3 18.5 cm housing which will spool quickly but is a better match for the 240 which won't choke on the smaller housing like the 300.
The 240 will not need to be run past 5500 rpm with the H1C turbo.The turbo would have to be larger to do that.

The 300 will make a better N/A engine and we can push the power with a larger cam than previously discussed if you don't mind a heavy low rpm lope.

You need the 1966 rods for the 240 turbo engine but it would also be good to have another set of 1965 to 1968 240 rods for the 300 engine.

A big valve, ported 300 head with 76cc chambers on the 240 with a flat top piston will give you an 8.8 compression ratio for turbocharging.

The N/A 300 can use the JR or SR head with two 500 cfm 2 barrel carbs.

[sandboxer]

You have the larger H1C with the 8 blade compressor.
The compressor wheel inducer should measure 54mm.
You can measure the inlet diameter to verify.
If you measure a 54mm inlet then the turbocharger can make 400 hp without straining.

The turbine has a T3 18.5 cm housing which will spool quickly but is a better match for the 240 which won't choke on the smaller housing like the 300.
The 240 will not need to be run past 5500 rpm with the H1C turbo.The turbo would have to be larger to do that.

The 300 will make a better N/A engine and we can push the power with a larger cam than previously discussed if you don't mind a heavy low rpm lope.

You need the 1966 rods for the 240 turbo engine but it would also be good to have another set of 1965 to 1968 240 rods for the 300 engine.

A big valve, ported 300 head with 76cc chambers on the 240 with a flat top piston will give you an 8.8 compression ratio for turbocharging.

The N/A 300 can use the JR or SR head with two 500 cfm 2 barrel carbs.

That’s a great plan. Alluding to FF’s post a while back...can the spit hole rods be used up to 5,500?
The general consensus was that it was risky. I’m not spending much time up there except when I need my “fix”. We are usually going up there and coming down shortly thereafter on the street.

I have the other 240 that’s mocked up in the car, so essentially 2 extra sets. The other option was the Molnar rod for the 2.100 journal.

The question is whether to save the 66 rods for the 300 and use the “undesirables” for the low rpm build, or not risk it at all.

FTF, have you tried the spit hole version yet?

[sandboxer]

I’m not sure how this is expected to work well. It looks like nothing lined up and there’s not a lot of meat for improvement.

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[pmuller9]

Here is a link to the spit hole subject.
The first 17 post pertain mainly to the 240 spit hole rod.
Starting at post #18 is relevant to the 300 spit hole rod.
viewtopic.php?p=611853#p611853

The 300 puts a lot more "G" forces on the rod at TDC than the 240.
I would not use the 300 spit hole rod for a N/A performance engine.

The question is whether to save the 66 rods for the 300 and use the “undesirables” for the low rpm build, or not risk it at all.

Then what rods would you use in the 240?
The 240 must use the 6.8" long 240 rod.

The Clifford runners also look small like the EFI manifold runners.
I would make my own as you suggested previously.

[sandboxer]

I’d use the 240 spit hole rods in the 240 Turbo.
The good 240 rods would be in the 300 NA.

[pmuller9]

The turbo is easier on the rods than N/A so I leave it up to you.
Meanwhile if you can find another set of "Good" 240 rods..

There is always the Molnar 7.130" Chevy six rods for the 240.
With the "Good" 240 rods or the Molnar rods, if you find a HX40 turbo later on you can push the rpm and HP.

[THE FRENCHTOWN FLYER]

sandboxer, I like your valve grinder. It is the same one I use. (Come to think of it so is the rotary phone) It is a wonderful machine in the hands of a skilled operator. I use mine for more than finishing valves.

I have used spit hole rods in both 240 and 300 drag cars. The 300 in my Willys has lots of runs on it and about 12,000 miles of street
use. The 240 only has a few hours of drag strip time on it, so, knock on wood, I've been lucky so far.

If you no longer have a use for the Clifford intake I may be interested in it, despite its flaws. Maybe trade for some other 300 junk of interest? PM me.

[Phase3]

I would like to add that im using the he351 holset on my 300 which spools just over 1500 rpm with a 9 cm ex housing. I will be using this on my 240 build and im fearing it may have some lag. That h1c will be directed more towards top end power especially on the 240. Wouldnt be surprised if you experience some lag.

[sandboxer]

Thanks FTF
What rpm are you seeing at the strip?

[sandboxer]

I would like to add that im using the he351 holset on my 300 which spools just over 1500 rpm with a 9 cm ex housing. I will be using this on my 240 build and im fearing it may have some lag. That h1c will be directed more towards top end power especially on the 240. Wouldnt be surprised if you experience some lag.

I’ve heard of spool up at 2,500... a bit late for sure, but with a standard Trans it should be fine. It’s a very light car.

[Phase3]

I would like to add that im using the he351 holset on my 300 which spools just over 1500 rpm with a 9 cm ex housing. I will be using this on my 240 build and im fearing it may have some lag. That h1c will be directed more towards top end power especially on the 240. Wouldnt be surprised if you experience some lag.

I’ve heard of spool up at 2,500... a bit late for sure, but with a standard Trans it should be fine. It’s a very light car.

Right on would be a blast in a light car. Very cool

[THE FRENCHTOWN FLYER]

Thanks FTF
What rpm are you seeing at the strip?

On the ones with stock rods we'll run it up to 5500. On a couple of times my son over revved his 240 and free revved the motor to 7000. I'm building him a replacement 303 and dropping his 240 in my Attic Anglia build.
https://www.jalopyjournal.com/forum/thr ... ia.704777/
That'll just be an old Grampa Car cruiser.

Anything over 5500 and I'd want something better for the long run.
And better rod bolts.

[pmuller9]

It looks like you can do the head work on a 300 carburetor head, be able to install 1.94"/1.60" valves and do the port work?

[sandboxer]

It looks like you can do the head work on a 300 carburetor head, be able to install 1.94"/1.60" valves and do the port work?

I believe I can do a decent job. I have plans for a flow bench but haven’t built it yet, so measuring my work isn’t possible at this point. I’d like to build the bench before I tackle the porting and I’m wanting to flow my manifolds as well. So I’m a ways off still.

I know that you’ve used the 2.02 before. Do you think that the 1:94 (or 1:90) is a better option?

[pmuller9]

I know that you’ve used the 2.02 before. Do you think that the 1:94 (or 1:90) is a better option?

The 2.02" showed gains at low valve lift points over the 1.94 but no advantage afterwards.
The 2.02 gets close to the spark plug ground strap and may be a problem with long reach plugs.
I indexed the plugs just to be sure there wouldn't be a problem.

I would stay with the 1.94" intake.

The drill and tap operation for screw in studs needs to be done on a vertical mill so that all the studs are in line with each other and also parallel with the valve stems.
Rocker stud center to valve stem center should be 1.585" to 1.590".
Cutting the rocker stud towers also needs to be done at the same time with the same set-up.

[sandboxer]

WorldChampGramp just summed it up nicely in his post regarding port dynamics. I’m going to play with my efi head, but in the meantime I’m still in with the Jr/Sr head program. I’d like a professional effort on my engine until I’ve made enough mistakes to proceed comfortably on my own. That might take a while...

[pmuller9]

What are you going to use for a Turbo exhaust manifold?

[sandboxer]

I’m building one. I’m torn between mounting the turbo right at the engine or in the back. Either way it gets an intercooler.

[THE FRENCHTOWN FLYER]

I believe I can do a decent job. I have plans for a flow bench but haven’t built it yet, so measuring my work isn’t possible at this point. I’d like to build the bench before I tackle the porting and I’m wanting to flow my manifolds as well. So I’m a ways off still.

Do you have the plans to build a flow bench? One of the rod magazines did an article on building one and I Xeroxed the plans with the intentions of building one, but the local community college where I used to teach upgraded their engine lab with a Superflow flow bench and some dynamometers, so I took a refresher course in engine building and that was enough to endear myself to the instructor who said I could use the college's anytime. You might try a similar approach.
(That course almost cost me the end of my thumb, but that's another story...)

[sandboxer]

Thanks FTF
What rpm are you seeing at the strip?

On the ones with stock rods we'll run it up to 5500. On a couple of times my son over revved his 240 and free revved the motor to 7000. I'm building him a replacement 303 and dropping his 240 in my Attic Anglia build.
https://www.jalopyjournal.com/forum/thr ... ia.704777/
That'll just be an old Grampa Car cruiser.

Anything over 5500 and I'd want something better for the long run.
And better rod bolts.

.

Beautiful build on the Anglia! Definitely one of my favourite cars (Topolino included).

The flowbench plans I got from flowbench.com.
There is quite a forum on building these.

Once again, the black art of interpreting and guessing information and outcomes of how flowbench data relates to engine performance will be a fun undertaking.

Also..!
I goofed on the Clifford intake. I should have taken the time right away to measure rather than be fooled by what my eyes gave me. The manifold checks out just fine after a caliper review. It needs a 16th pulled off the radius with the grinder. I’ll probably just hand file it to be safe.

I suppose the gasket is so oversized to prevent any chance of overlay into the port.

[pmuller9]

I’m building one. I’m torn between mounting the turbo right at the engine or in the back. Either way it gets an intercooler.

If you put the turbo in the back then you can use a full length tube header.

[THE FRENCHTOWN FLYER]

Also..!
I goofed on the Clifford intake...The manifold checks out just fine after a caliper review.

You win!!!

[sandboxer]

Also..!
I goofed on the Clifford intake...The manifold checks out just fine after a caliper review.

You win!!!

Too funny:)

[sandboxer]

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Two good reads!

[pmuller9]

Yes, very good reading.

Add pages 6 thru 18 of the Garrett catalog as good reading. It is important to be able to read a compressor map.
https://www.dropbox.com/s/wqnbemrygclw1 ... 5.pdf?dl=0

Here is one of the best tools for planning a turbo project. Have fun with it.
http://www.turbos.bwauto.com/aftermarke ... sin=92044&

[sandboxer]

Thanks pmuller
I’ll definitely have fun with that.

[sandboxer]

A question I’ve always pondered...
Rear mount turbo decreases heat input, but the header improves flow. Trade off for sure. Would you wrap the header and exhaust all the way to the turbo?

[THE FRENCHTOWN FLYER]

From a thermodynamic standpoint it would help turbo efficiency (PV=nRT). To what degree I don't know. But from a pragmatic standpoint I would worry about the long-term effect of heat and water/salt on the tubes. I would not wrap for that reason. Of course, if you make everything stainless it might be a moot point. I would not undertake a turbo installation unless I do it all in stainless.

[Mdixon300f100]

Up here in New England wrapped steel headers don’t last. If it’s off the road during winter months probably not a big deal. Ceramic coating is probably the best for longevity, stainless would make all that unnessary beyond thermal efficiency, ie faster spool, and requires less heat shielding. Stainless doesn’t radiate heat nearly as much as mild or cast steel.

[sandboxer]

I have a Hedman truck header that I’ll never use. I was going to cut it up and use the bits to make one that suits my format. It’s an interim solution that will give me a functioning prototype. I won’t wrap it though.
If that works out I’ll duplicate in stainless.
Thanks!

[sandboxer]

Bought some never used SBF Manleys today.

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1:94/1:60
5.080 length

Is anyone familiar with this style of valve?

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[pmuller9]

Those valves are .270" longer than early stock valves. You will be able to go .800" valve lift.

I used a similar set of undercut valve stems and dish valve head in the last head only my valves were only 4.911" long.
https://www.dropbox.com/s/5t7b6y8h5vdpu ... r.JPG?dl=0

[sandboxer]

Only .800? Bummer:)

Does this mean that I don’t have to mill down the stud boss for the Crane Gold rockers?

[pmuller9]

Only .800? Bummer:)

Does this mean that I don’t have to mill down the stud boss for the Crane Gold rockers?

Hopefully but you will need to measure.
Look for 1.5" from the top of the valve tip to the top of the stud boss.

[sandboxer]

Bought these beauties today.
BBC Crane Golds
1:7
7/16” stud

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Time for some head work:)

Thanks Lunatic Fringe and pmuller for your expert advice on what to look for.

[pmuller9]

Which head are these fine looking parts going on/in?

[sandboxer]

Which head are these fine looking parts going on/in?

I’ll be using one of my 240 heads to begin with.
I think I’d like to turbo the 240 and NA the 300. I’ll post photos of the aluminum intake I’m fabricating when it’s done, but it’ll have a common plenum with a single 4 barrel and dual 2 barrel option. In addition, I’ll make provisions for an isolator in the plenum for the dyno session. I’d like to see how the pressure waves are affected by isolating cylinders 123 from 456 on a dual carb set-up.
It’s a long way off, but taking shape...

I’m dying to find out about the JR/SR head results. I think these rockers would look awesome on a SR head!

[pmuller9]

If you turbo the 240 it should get a 300 carb head so you can use a flat top piston.

[sandboxer]

If you turbo the 240 it should get a 300 carb head so you can use a flat top piston.

I’m definitely heeding your advice on that. I have a carb head that is reserved for the turbo. Because I have 3 240 heads, one will become my NA mule for my intake manifold build.
I haven’t pulled the valve cover on the carb head to see if it’s pedestal, but given the year of build, I’m assuming it will be. More to come...

[sandboxer]

I measured the heights of all my heads’ pedestals, 240 and 300, and the heights are all the same. What does talk about machining them down for stud rockers mean if the stud rockers already use the pedestals in place?
Am I missing something?

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[Shorty]

the way I understand it is the boss needs to be machined down when the pressed in stud is pulled and the hole is threaded because the threaded stud will have a section that is hex shaped for the wrench when tightening. If the boss is not machined there would be potential for interference with the rocker.

[sandboxer]

the way I understand it is the boss needs to be machined down when the pressed in stud is pulled and the hole is threaded because the threaded stud will have a section that is hex shaped for the wrench when tightening. If the boss is not machined there would be potential for interference with the rocker.

Understood!
Thanks Shorty

[Shorty]

I can't take too much credit for that, I only know this from reading wisdom on this forum from many who have much more experience than I do, but glad I could help.

[pmuller9]

The BBC and BBF roller rockers are .050" longer than the 300 six rockers so they have to sit lower on the stud to get the roller tip centered on the valve stem tip.
See the following link at post #21
viewtopic.php?p=618023#p618023

This is a good example of the setup for the Crane 1.7 ratio roller rocker.
We started off with the ideal rocker setup that you always see in the valve train geometry videos and quickly discover that the longer BBC rocker makes the ideal setup impossible.
Start on post #212 and read to the end of the thread.
Tom worked hard on this.
viewtopic.php?p=613808#p613808

[sandboxer]

Thanks to both of you for that thread.
I remember reading it thoroughly as it unfolded but obviously my retention abilities need work. That is an epic thread. Very helpful.

[sandboxer]

I have another dilemma.
The exhaust ports measure 1500 sq. mm
- 1 1/2” header ID equals 1134 sq. mm
- 1 5/8” header ID equals 1334 sq. mm

Either way, a 1 3/4” header tube will barely equal the exhaust port size. Everything smaller is a huge step down.

Thoughts?