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So I have a plan but now im Second guessing myself.

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48kenworth
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So I have a plan but now im Second guessing myself.

Post #1 by 48kenworth » Tue May 28, 2019 10:39 pm

So as of right now my 78 f100, np435, 2.75 rear end, and powered by a .030 over 300 has an offy DP, 500cfm edelbrock with annualar boosters,
Chevy rockers, EFI manifolds, 2.5" exhaust, and 12degrees base timing rolling smoothly up to 38 degrees at 3000rpm.

I scored a 240 head that I'm am planning on having worked over, bigger valves, porting, gasket matching, screw in studs, all the normal stuff...

At the same time I swap the head I intend to throw an isky 256 supercam and proper springs at it.

This is still a work pickup though that does get labored fairly hard at times and I'm really concerned that I may have issues running 87 octane once I swap in the head and cam. Truth is I'm really not intelligent enough to determine if this set up will work on regular unleaded?

I have also no yet determined if the high ratio rockers will work with that cam or not..

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Re: So I have a plan but now im Second guessing myself.

Post #2 by THE FRENCHTOWN FLYER » Tue May 28, 2019 11:03 pm

I would knock back the total timing to 33 - 34 degrees.
Sure, the 1.76 rockers will work with your combo. Be sure to check for coil bind and sufficient clearances in all the usual places.
Last edited by THE FRENCHTOWN FLYER on Tue May 28, 2019 11:25 pm, edited 1 time in total.
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Re: So I have a plan but now im Second guessing myself.

Post #3 by pmuller9 » Tue May 28, 2019 11:24 pm

When the engine was bored .030" over, what pistons were used?

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Re: So I have a plan but now im Second guessing myself.

Post #4 by 48kenworth » Wed May 29, 2019 7:15 am

pmuller9 wrote:When the engine was bored .030" over, what pistons were used?


They are just stock rebuilder pistons.

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Re: So I have a plan but now im Second guessing myself.

Post #5 by pmuller9 » Wed May 29, 2019 11:04 am

Assuming the current static compression ratio is around 8.4
The Isky 256 cam has 12 degrees less .006" duration than the stock cam and closes the intake valve 10 degrees sooner than the stock cam if it is installed straight up.
That will raise the Dynamic Compression Ratio by 0.5

The 240 head will raise the DCR another 0.5 putting the final DCR around the 7.6

Way too high for 87 to 89 octane pump gas.

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Re: So I have a plan but now im Second guessing myself.

Post #6 by 48kenworth » Wed May 29, 2019 1:17 pm

I was under the impression that the smaller chambers would affect static compression by 0.5 and would have a lesser effect on dynamic compression. We are having a conversation that's on the fringes of my mathematical abilities.

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Re: So I have a plan but now im Second guessing myself.

Post #7 by pmuller9 » Wed May 29, 2019 2:45 pm

Let's say that the static compression ratio is 8.4
That's with a 76cc chamber and 22cc pistons .025" in the hole.
The Dynamic compression ratio is 6.6 with the stock cam 4 degrees retarded.

If you change to the 240 head with a 68cc chamber the static compression ratio goes to 9.0 and the dynamic goes to 7.0 which is still good for 87 octane gas.

If you change cams to the Isky 256 and install it straight up with no advance the static compression ratio stays at 9.0 but the dynamic compression ratio moves up to 7.6 which is too high for 87 or 89 octane gas.

You would need a larger cam which is what we have been recommending for all applications.
The Crower 284HDP (19205) or the Schneider 140H (13912) would take care of the problem and give you a very wide power band with plenty of low end torque.

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Re: So I have a plan but now im Second guessing myself.

Post #8 by 48kenworth » Wed May 29, 2019 3:44 pm

pmuller9 wrote:Let's say that the static compression ratio is 8.4
That's with a 76cc chamber and 22cc pistons .025" in the hole.
The Dynamic compression ratio is 6.6 with the stock cam 4 degrees retarded.

If you change to the 240 head with a 68cc chamber the static compression ratio goes to 9.0 and the dynamic goes to 7.0 which is still good for 87 octane gas.

If you change cams to the Isky 256 and install it straight up with no advance the static compression ratio stays at 9.0 but the dynamic compression ratio moves up to 7.6 which is too high for 87 or 89 octane gas.

You would need a larger cam which is what we have been recommending for all applications.
The Crower 284HDP (19205) or the Schneider 140H (13912) would take care of the problem and give you a very wide power band with plenty of low end torque.


Thanks a bunch! I considered a longer duration cam to begin with but was concerned that my tall gears would really make crawling though a pasture with a load very difficult. Although I am well aware that I do not have math on my side I am having a difficult time visualizing good performance from 1000-3000rpm with a cam who's manufacturer states it's power range begins at 2500rpm. I trust you and the French town flyer as you have both been good to me but somebody will have to assure me that snheider cam won't be lumpy and gutless at 800rpm.

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Re: So I have a plan but now im Second guessing myself.

Post #9 by pmuller9 » Wed May 29, 2019 4:41 pm


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Re: So I have a plan but now im Second guessing myself.

Post #10 by BigBlue94 » Wed May 29, 2019 7:22 pm

I can actually add to a thread haha!

I'm running 9.75 static CR with a dynamic CR of 7.47. It runs great on 91 octane. It ran okay on a 50/50 mix of 91 and 85 octane (at a much higher altitude than I live).

I am running the Schneider 140H cam and I can tell you it is NOT a gutless wonder off idle. It has PLENTY of grunt from idle to 4500+. Very pleased with it. It's also not overly lopey, and I get about 17-18" hg of vacuum at idle. It will idle all the way down to about 550 rpm, but I have it set at 800.

I run a 450 quickfuel 4bbl with a Clifford intake, headers, and 1.6 roller rockers with an HEI handling the ignition. It's in a bronco with np435 manual trans, 4.56 gears, and 37" tires. It will do 85mph down the highway all day long, although 65-70 is much more comfortable.
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: So I have a plan but now im Second guessing myself.

Post #11 by 48kenworth » Thu May 30, 2019 9:19 am

I'm going to order the Schneider 140h this all makes better sense after reading the same conversation that was had with bigblue94 in the thread linked. Cam selection for a 300 is a very different thing than for a small block. It is can be hard to look at the straight 6 like a big block and harder still to look at manufacturers advertised rpm ranges and know they are not accurate for the 300.

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Re: So I have a plan but now im Second guessing myself.

Post #12 by pmuller9 » Thu May 30, 2019 10:34 am

You will want to use a 1.6 ratio rocker with the 140H cam.
I don't remember anyone using the stock style stamped rockers but it shouldn't be a problem with a light valve spring.
Everyone to date has used roller rockers.

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Re: So I have a plan but now im Second guessing myself.

Post #13 by 48kenworth » Thu May 30, 2019 2:08 pm

I have not called Schneider yet but I would have assumed some stiff springs would be recommended.

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Re: So I have a plan but now im Second guessing myself.

Post #14 by sandboxer » Thu May 30, 2019 6:03 pm

Talked to Kevin at Schneider yesterday and was told that the 142F would fall on its face at 5500 because of the poor breathing of the head. That can is rated to 6500. As well, Jerry at Schneider today confirmed that they have all the requisite springs.

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Re: So I have a plan but now im Second guessing myself.

Post #15 by 48kenworth » Thu May 30, 2019 7:20 pm

That's kinda funny I talked to Jerry today and he said that he has been getting blown up with Ford inline 6 guys all week. I purchased the cam, lifters, and 110psi seat pressure springs while we were on the phone today.

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Re: So I have a plan but now im Second guessing myself.

Post #16 by 48kenworth » Thu May 30, 2019 7:24 pm

pmuller9 wrote:You will want to use a 1.6 ratio rocker with the 140H cam.
I don't remember anyone using the stock style stamped rockers but it shouldn't be a problem with a light valve spring.
Everyone to date has used roller rockers.


So I have to ask why you Are recommending stepping away from the 1.76 rockers? With the 140h cam that will give me .525 valve lift. Are you thinking the affect on ramp rate will affect low end torque?

I have seen stamped rockers used on some pretty wild setups here and there over the years. I don't suspect there will be any issue with my setup.

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Re: So I have a plan but now im Second guessing myself.

Post #17 by 48kenworth » Thu May 30, 2019 7:31 pm

BigBlue94 wrote:I can actually add to a thread haha!

I'm running 9.75 static CR with a dynamic CR of 7.47. It runs great on 91 octane. It ran okay on a 50/50 mix of 91 and 85 octane (at a much higher altitude than I live).

I am running the Schneider 140H cam and I can tell you it is NOT a gutless wonder off idle. It has PLENTY of grunt from idle to 4500+. Very pleased with it. It's also not overly lopey, and I get about 17-18" hg of vacuum at idle. It will idle all the way down to about 550 rpm, but I have it set at 800.

I run a 450 quickfuel 4bbl with a Clifford intake, headers, and 1.6 roller rockers with an HEI handling the ignition. It's in a bronco with np435 manual trans, 4.56 gears, and 37" tires. It will do 85mph down the highway all day long, although 65-70 is much more comfortable.


It would be interesting at this point to see a video of yours running. I'm excited to get mine together.

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Re: So I have a plan but now im Second guessing myself.

Post #18 by BigBlue94 » Thu May 30, 2019 7:34 pm

I too used their lifters, since they wont warranty the stick if you dont. Jerry originally recommended the 131H for me, but I wanted a bit bigger. PMuller helped me choose the 140H.

I also used their breakin additive and the ZDDP additive once the rings seated.

When I 'found' Schneider, I was amazed by the number of big six cams they offered. Be advised that they grind all cams to order, so it takes a bit longer.

The reason for 1.6 rockers is the cam was designed for them. With 1.73 rockers, the cam curve will be slightly different. The valves will be moving faster and that changes how the cam works. At least that's what I understood when I asked that question

I have a couple videos but they arent the best quality. I'll post em
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: So I have a plan but now im Second guessing myself.

Post #19 by BigBlue94 » Thu May 30, 2019 7:39 pm

Sorry for the lifter tick, didnt have em adjusted quite right. Breakin and first drive. Exhaust is 3" through a borla xr1 muffler.

https://youtu.be/IjIARlqU91w

https://youtu.be/_-cn1HqEKmA

https://youtu.be/zobA_DZ5Zzs
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: So I have a plan but now im Second guessing myself.

Post #20 by 48kenworth » Thu May 30, 2019 8:21 pm

BigBlue94 wrote:
The reason for 1.6 rockers is the cam was designed for them. With 1.73 rockers, the cam curve will be slightly different. The valves will be moving faster and that changes how the cam works. At least that's what I understood when I asked that question

I have a couple videos but they arent the best quality. I'll post em


Yes changing rocker ratio alters the cam profile as far as the valves see it. I discussed the higher ratio rockers with Jerry and he didn't think they would not compliment the build but we didn't get into there affect on the power curve. Piston clearance is also a concern for me at this point.

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Re: So I have a plan but now im Second guessing myself.

Post #21 by THE FRENCHTOWN FLYER » Thu May 30, 2019 8:35 pm

I have a current build going on that I am going to use stamped stock rocker arms. The reason for that is I am running a back-to-back experiment on replacing a 240 with a 300 in the same vehicle and I want to keep the engines similar in build-up. I plan to contour dress the valve tip ends with a fine emery wheel since they show some wear witness marks. We'll see.
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Re: So I have a plan but now im Second guessing myself.

Post #22 by pmuller9 » Thu May 30, 2019 9:22 pm

The reason for a little concern using the stamped rockers over .500" lift has to do with the extra pressure on the pivot ball causing squeaking.
Also need to check the pattern on the valve stem tip.
Otherwise there is some performance to be gained with the extra lift and duration from the increased ratio.
There is no harm starting with stamped rockers and if they give a problem they can be switched to a roller rocker.

There is not a problem with piston to valve clearance on a 300 six unless a domed piston is being used.

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Re: So I have a plan but now im Second guessing myself.

Post #23 by pmuller9 » Thu May 30, 2019 10:32 pm

48kenworth wrote:It would be interesting at this point to see a video of yours running. I'm excited to get mine together.

Here is a video of the Erson cam equivalent E270321 (Hi-Flow AH) .504"/.504" 220/220 284/284 110deg.
https://youtu.be/Ah7alvyiYT0

This is also one of the engines that had squeaky stamped rockers and finally switch to rollers to solve the problem.

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Re: So I have a plan but now im Second guessing myself.

Post #24 by 1986F150six » Fri May 31, 2019 12:47 pm

AbandonedBronco's ride! :thumbup:

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Re: So I have a plan but now im Second guessing myself.

Post #25 by BigBlue94 » Fri May 31, 2019 1:22 pm

1986F150six wrote:AbandonedBronco's ride! :thumbup:


Yep, I got to ride in it when we were both in Moab for the Bronco Safari a few weeks ago. It's got great power and smooth performance. Definitely a good build.
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: So I have a plan but now im Second guessing myself.

Post #26 by 48kenworth » Sun Jun 16, 2019 6:23 pm

Okay I must be calculating something wrong here.

Trying to decide about milling the head and using a dcr calculator my dynamic compression is to high.
So here are the figures I'm using
Bore 4.03
Stroke 3.98
Combustion chamber volume 68cc
Gasket thickness 0.048
Gasket bore 4.17
Deck clearance .025
Ivc @ .050 41 degrees for the Schneider 140h this is all numbers I sourced trying to do this myself.
I'm coming up with 7.56 for
8.85 static.
I came up with ivc @ .050 by the following 222÷2= 111+110= 221- 180= 41.
Last edited by 48kenworth on Sun Jun 16, 2019 7:04 pm, edited 1 time in total.

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Re: So I have a plan but now im Second guessing myself.

Post #27 by Max_Effort » Sun Jun 16, 2019 6:43 pm

48kenworth wrote:Okay I must be calculating something wrong here.

Trying to decide about milling the head and using a dcr calculator my dynamic compression is to high.
So here are the figures I'm using
Bore 4.03
Stroke 3.98
Combustion chamber volume 68cc
Gasket thickness 0.048
Gasket bore 4.17
Deck clearance .025
Vic @ .050 41 degrees for the Schneider 140h this is all numbers I sourced trying to do this myself.


If you are going by .050” for IVC, use this calculator https://uempistons.com/p-27-compression ... lator.html

Is the gasket actually .048”? Typical is .038”

What is the piston top? Flat top, no valve relief, no dish?

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Re: So I have a plan but now im Second guessing myself.

Post #28 by 48kenworth » Sun Jun 16, 2019 7:09 pm

Max_Effort wrote:
48kenworth wrote:Okay I must be calculating something wrong here.

Trying to decide about milling the head and using a dcr calculator my dynamic compression is to high.
So here are the figures I'm using
Bore 4.03
Stroke 3.98
Combustion chamber volume 68cc
Gasket thickness 0.048
Gasket bore 4.17
Deck clearance .025
Vic @ .050 41 degrees for the Schneider 140h this is all numbers I sourced trying to do this myself.


If you are going by .050” for IVC, use this calculator https://uempistons.com/p-27-compression ... lator.html

Is the gasket actually .048”? Typical is .038”

What is the piston top? Flat top, no valve relief, no dish?


I tried a few calculators. I don't really like the .050 part but it seems all the calculators that ask all the questions use it. Pistons are just stock rebuilder pistons, The .048 was taken from some fine internet forum research. If 0.038 is correct for our gaskets and the math I'm doing is right i won't be able to run 87 octane. Y'all bear with me. I'm a class 8 truck mechanic and not accustomed to doing custom builds on a gassers. My math has to be wrong.

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Re: So I have a plan but now im Second guessing myself.

Post #29 by CNC-Dude » Sun Jun 16, 2019 7:14 pm

Another issue with using stock style stamped steel rockers for valve lifts over .500" is that the slots can't allow the rockers to pivot that much without binding against the rocker studs. Even in high performance versions of Big Block Chevy's, GM had to make special long slot stamped steel rockers for use with cams that had more than .500" lift. So if using higher ratio steel aftermarket rockers, don't assume they can accommodate lifts beyond a certain lift unless they clearly specify they can.
Image

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Re: So I have a plan but now im Second guessing myself.

Post #30 by 48kenworth » Sun Jun 16, 2019 7:18 pm

CNC-Dude wrote:Another issue with using stock style stamped steel rockers for valve lifts over .500" is that the slots can't allow the rockers to pivot that much without binding against the rocker studs. Even in high performance versions of Big Block Chevy's, GM had to make special long slot stamped steel rockers for use with cams that had more than .500" lift. So if using higher ratio steel aftermarket rockers, don't assume they can accommodate lifts beyond a certain lift unless they clearly specify they can.


Yea I've been looking into that and I'm take going to take a wait and see approach to that deal. But I've already been on summit scoping out roller rockers and deciding on how I'm going to graft two valve covers together if I have to. Or buying your spacer.
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Re: So I have a plan but now im Second guessing myself.

Post #31 by 48kenworth » Sun Jun 16, 2019 7:22 pm

Right now I really need somebody to help me learn how to grasp the math and do it right without having my hand held.

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Re: So I have a plan but now im Second guessing myself.

Post #32 by Mdixon300f100 » Sun Jun 16, 2019 7:43 pm

The felpro 1024 is .038 torqued. Bore is 4.18. What’s the dish in the piston? Common rebuild piston is 20cc dish.

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Re: So I have a plan but now im Second guessing myself.

Post #33 by 48kenworth » Sun Jun 16, 2019 7:52 pm

Mdixon300f100 wrote:The felpro 1024 is .038 torqued. Bore is 4.18. What’s the dish in the piston? Common rebuild piston is 20cc dish.

The engine is currently a runner and I can't afford for the pickup it's in to be eating up a bay in my shop for weeks with the head off so
I'm having to assume the dish in the pistons. I didn't check them when I lapped the valves on the stock head. I assumed 25cc.

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Re: So I have a plan but now im Second guessing myself.

Post #34 by Max_Effort » Sun Jun 16, 2019 8:03 pm

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Re: So I have a plan but now im Second guessing myself.

Post #35 by 48kenworth » Sun Jun 16, 2019 8:07 pm

Yea I used that calculator. I may have to rethink things here. I need to run 87 octane and I am under the impression to do so requires dynamic compression to be in the low 7's?

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Re: So I have a plan but now im Second guessing myself.

Post #36 by pmuller9 » Sun Jun 16, 2019 9:17 pm

That is the calculator I use also but I use the intake valve closing point based on the .006" lobe lift point (advertised duration) not the .050" plus 15 degrees.
There are too many variations between the advertised and .050 durations on camshafts.

For the purposes of detonation, DCR is simply a reference number that is specific to an engine in our case being the 300 six.
It is observed using many different 300 engine builds that at sea level the DCR range for pump gas is between 7.0 to 7.5 allowing margin for other variations.

This reference number is calculated by using the actual intake valve closing point approximately .010" off the seat.
The SAE standard for the advertised duration is calculated on the .006" lobe lift.
Some will argue that some cam companies will use a lesser lobe lift to increase the advertised duration but all you can do is use what is given
Using the .006" lobe lift number gives that value using the many different DCR calculators available online.

If you install the 140H cam straight up 280÷2 = 140 + 110 -180 = 70 degrees ABDC
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Re: So I have a plan but now im Second guessing myself.

Post #37 by Max_Effort » Sun Jun 16, 2019 9:37 pm

This is with the IVC at .006” timing (adding 29 to the 41 at .050”) if Schneider uses gross duration at .006” . Some cam companies use different lift points...

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Re: So I have a plan but now im Second guessing myself.

Post #38 by 48kenworth » Mon Jun 17, 2019 5:54 am

It's amazing how much the numbers change when not following the calculators instructions. I was following the instructions on different calculators and coming up with Dcr's closer to 8.

It's hard to play the game when you don't know the rules were changed.

But at least the question is answered, No I cannot mill the head any further than necessary to flatten it.

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Re: So I have a plan but now im Second guessing myself.

Post #39 by Max_Effort » Mon Jun 17, 2019 8:33 am

pmuller9 wrote:The SAE standard for the advertised duration is calculated on the .006" lobe lift.
Some will argue that some cam companies will use a lesser lobe lift to increase the advertised duration but all you can do is use what is given
Using the .006" lobe lift number gives that value using the many different DCR calculators available online.


This is or was done quite a bit, listing advertised anywhere from 004", .006", .012", .020"

The company makes the cam seem larger, smaller, more or less aggressive. Very common with marketers of the generic "white box" cams that are made by CMC and sold under many different brand names. It was a big reason Harvey Crane pushed the .050" duration numbers. Of course there is a lot more than advertised or .050" to a lift curve and how the cam performs.

Then there is Harley with .053" lift numbers....

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Re: So I have a plan but now im Second guessing myself.

Post #40 by 48kenworth » Mon Jun 17, 2019 9:27 am

It's not enough for somebody to tell me what I need to do. I want to understand the reasoning and gain the wisdom to make determinations without help. I am truly grateful for the people here who do not know me but take the time to share knowledge and wisdom. To be honest knowing this stuff will likely make me better at my job! At least indirectly.

So as I have been figuring this, i cannot safely mill the head to reduce combustion chamber size considering my goals. If I were working over the short block I may would have been able to get my pistons to zero deck and polish the combustion chambers to improve the Quincy area and be able to squeeze a little more. But that part is only a hypothetical idea I came to in my figuring.

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Re: So I have a plan but now im Second guessing myself.

Post #41 by pmuller9 » Mon Jun 17, 2019 10:05 am

Review
There is one group of Hypereutectic pistons that are advertised at 22cc dish volume.
They should be checked for accuracy once you get them.
The few other possibilities have either way too little or to much volume.

The compression ratio should limited to 9:1 for 87 octane gas with the Schneider 140H cam.

This puts the pistons at least .025" in the hole which means very little block decking, enough to clean up the top of the block or non at all if the deck is straight.

The cylinder head combustion chamber can be modified to add volume by unshrouding the valves and chamber polishing.
The cylinder head should be completed first because the chamber volume determines the rest.
If you could get the chamber volume out to 72-73cc then you could zero deck the pistons for better quench.

Do you have a 100cc Burette to measure head chamber and piston dish volume?
Do you also have a degree wheel, dial indicator and magnetic base to degree the cam?

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Re: So I have a plan but now im Second guessing myself.

Post #42 by 48kenworth » Mon Jun 17, 2019 1:14 pm

pmuller9 wrote:Review
There is one group of Hypereutectic pistons that are advertised at 22cc dish volume.
They should be checked for accuracy once you get them.
The few other possibilities have either way too little or to much volume.

The compression ratio should limited to 9:1 for 87 octane gas with the Schneider 140H cam.

This puts the pistons at least .025" in the hole which means very little block decking, enough to clean up the top of the block or non at all if the deck is straight.

The cylinder head combustion chamber can be modified to add volume by unshrouding the valves and chamber polishing.
The cylinder head should be completed first because the chamber volume determines the rest.
If you could get the chamber volume out to 72-73cc then you could zero deck the pistons for better quench.

Do you have a 100cc Burette to measure head chamber and piston dish volume?
Do you also have a degree wheel, dial indicator and magnetic base to degree the cam?


So I am clear I'm not making changes to the short block, I was only doing what if type thinking. Yes I have a degree wheel and dial indicator. Any CC measuring I do will have to be with my cattle syringe.

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Re: So I have a plan but now im Second guessing myself.

Post #43 by pmuller9 » Mon Jun 17, 2019 9:41 pm

48kenworth wrote:So I am clear I'm not making changes to the short block, I was only doing what if type thinking.

I was confused earlier thinking the shortblock was going to be rebuilt. Too many project to keep track of.

The short block should be able to stay as is.
When you take the head off it would be important to bring a piston to TDC and measure how far down the piston is from the top of the block and also cc the dish in the piston.

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Re: So I have a plan but now im Second guessing myself.

Post #44 by 68Flareside240 » Tue Jun 18, 2019 10:34 am

You can get a 100mL burette for about $20 online. A large syringe may get you close, but I have seen some that were quite a bit off.

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Re: So I have a plan but now im Second guessing myself.

Post #45 by 48kenworth » Thu Jul 04, 2019 4:49 pm

Ok head is done, engine is apart. Final numbers are in.
Screenshot_20190704-153814.png
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Re: So I have a plan but now im Second guessing myself.

Post #46 by bubba22349 » Thu Jul 04, 2019 5:46 pm

:beer: Congrats looks like you achieved your compression goal! :thumbup: :nod:
A bad day Drag Racing is still better than a good day at work!

I am still hunting for a project car to build but with my current low budget it's not looking so good. My Ex- Fleet of Sixes these are all long gone! :bang: 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: So I have a plan but now im Second guessing myself.

Post #47 by 48kenworth » Sun Jul 07, 2019 12:08 am

Well I got it together, the cam ran in, and had a chance to play with it a little and do some tuning. I can say if I'm hotrodding it the thing runs great but the driving manners at below 1100 rpm are terrible. Not sure yet what my next move is.

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Re: So I have a plan but now im Second guessing myself.

Post #48 by Max_Effort » Sun Jul 07, 2019 5:40 am

48kenworth wrote:Well I got it together, the cam ran in, and had a chance to play with it a little and do some tuning. I can say if I'm hotrodding it the thing runs great but the driving manners at below 1100 rpm are terrible. Not sure yet what my next move is.


What are the drive ability issues?

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Re: So I have a plan but now im Second guessing myself.

Post #49 by 48kenworth » Sun Jul 07, 2019 7:47 am

Max_Effort wrote:
48kenworth wrote:Well I got it together, the cam ran in, and had a chance to play with it a little and do some tuning. I can say if I'm hotrodding it the thing runs great but the driving manners at below 1100 rpm are terrible. Not sure yet what my next move is.


What are the drive ability issues?

Under load it gradually goes lean, then nearly stalls, darts back rich with a surge of power causing the pickup to lunge, then repeats over and over. Once the rpm is high enough to overcome that it is just generally sluggish and tapers into vibrant power as rpm increases. It acts like it has a very aggressive cam in it.

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Re: So I have a plan but now im Second guessing myself.

Post #50 by Max_Effort » Sun Jul 07, 2019 8:05 am

48kenworth wrote:
Max_Effort wrote:
48kenworth wrote:Well I got it together, the cam ran in, and had a chance to play with it a little and do some tuning. I can say if I'm hotrodding it the thing runs great but the driving manners at below 1100 rpm are terrible. Not sure yet what my next move is.


What are the drive ability issues?

Under load it gradually goes lean, then nearly stalls, darts back rich with a surge of power causing the pickup to lunge, then repeats over and over. Once the rpm is high enough to overcome that it is just generally sluggish and tapers into vibrant power as rpm increases. It acts like it has a very aggressive cam in it.


You ended up with the 140H? That would be considered a mild cam.

What carb does it have? Edelbrock? I’d be looking there after I ruled out vacuum leaks etc..

https://www.hotrod.com/articles/rebuild ... arburetor/

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