2 heads better than 1 - power porting E7TE iron.

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MadBill
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Re: 2 heads better than 1 - power porting E7TE iron.

Post by MadBill »

Carnut1 wrote: Mon Nov 19, 2018 6:12 pm Very happy, Now if we could just get some thin head gaskets donated to fix that miserable quench I would be thrilled! I know, I am a pain. I will add that the larger cam and fixed quench with some timing runs will cut deep into that stock block's max strength limits. Thanks, Charlie
0.015" SBC gaskets are < $10 ea. from some sources...
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Re: 2 heads better than 1 - power porting E7TE iron.

Post by travis »

MadBill wrote: Mon Nov 19, 2018 9:21 pm
Carnut1 wrote: Mon Nov 19, 2018 6:12 pm Very happy, Now if we could just get some thin head gaskets donated to fix that miserable quench I would be thrilled! I know, I am a pain. I will add that the larger cam and fixed quench with some timing runs will cut deep into that stock block's max strength limits. Thanks, Charlie
0.015" SBC gaskets are < $10 ea. from some sources...
I’m not sure how your going to make those work on an SBF :wink:
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Re: 2 heads better than 1 - power porting E7TE iron.

Post by MadBill »

My finger's on autopilot... :oops:
Fewer bolt holes, fewer choices, more $$...it ain't easy being Ford. :)
The thinnest I could find in a quick search is 0.027".
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Re: 2 heads better than 1 - power porting E7TE iron.

Post by David Vizard »

travis wrote: Mon Nov 19, 2018 9:05 pm I’m curious why the 268/220 .512” lobe, instead of the 268/218 (or 222) .544” lobe Mike has at his disposal?
Jesus - don't let Mike know but that lobe i quoted might have been the CC one on my desk not Mikes - --- ehhh - 76 next B/day!!!
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Re: 2 heads better than 1 - power porting E7TE iron.

Post by travis »

David Vizard wrote: Mon Nov 19, 2018 10:10 pm
travis wrote: Mon Nov 19, 2018 9:05 pm I’m curious why the 268/220 .512” lobe, instead of the 268/218 (or 222) .544” lobe Mike has at his disposal?
Jesus - don't let Mike know but that lobe i quoted might have been the CC one on my desk not Mikes - --- ehhh - 76 next B/day!!!
DV
Don’t feel bad...I’ve been having plenty of “senior” moments lately. I’ll be 47 in a few weeks :oops:

I was just curious is all. I’ve got one of Mikes 264/268, 218/222, .544/.544 hydraulic rollers here for a 351w I’m putting together for one of my trucks. I think it will do ok
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Re: 2 heads better than 1 - power porting E7TE iron.

Post by travis »

MadBill wrote: Mon Nov 19, 2018 9:52 pm My finger's on autopilot... :oops:
Fewer bolt holes, fewer choices, more $$...it ain't easy being Ford. :)
The thinnest I could find in a quick search is 0.027".
I was just giving you a hard time lol

Cometic is about your only choice for thin sbf head gaskets...and they certainly don’t give them away
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Re: 2 heads better than 1 - power porting E7TE iron.

Post by CamKing »

travis wrote: Mon Nov 19, 2018 9:05 pm I’m curious why the 268/220 .512” lobe, instead of the 268/218 (or 222) .544” lobe Mike has at his disposal?
It will be a 268/222, .544" on 110
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Re: 2 heads better than 1 - power porting E7TE iron.

Post by David Vizard »

CamKing wrote: Tue Nov 20, 2018 9:39 am
travis wrote: Mon Nov 19, 2018 9:05 pm I’m curious why the 268/220 .512” lobe, instead of the 268/218 (or 222) .544” lobe Mike has at his disposal?
It will be a 268/222, .544" on 110
Thanks for the correction Mikey.
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Re: 2 heads better than 1 - power porting E7TE iron.

Post by Carnut1 »

CamKing wrote: Tue Nov 20, 2018 9:39 am
travis wrote: Mon Nov 19, 2018 9:05 pm I’m curious why the 268/220 .512” lobe, instead of the 268/218 (or 222) .544” lobe Mike has at his disposal?
It will be a 268/222, .544" on 110
Will that be a hft or hyd roller? Thanks, Charlie
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Re: 2 heads better than 1 - power porting E7TE iron.

Post by David Vizard »

Carnut1 wrote: Tue Nov 20, 2018 10:45 am
CamKing wrote: Tue Nov 20, 2018 9:39 am
travis wrote: Mon Nov 19, 2018 9:05 pm I’m curious why the 268/220 .512” lobe, instead of the 268/218 (or 222) .544” lobe Mike has at his disposal?
It will be a 268/222, .544" on 110
Will that be a hft or hyd roller? Thanks, Charlie
Hyd. roller.

Just had a call from Mike - good news - cam will be shipping today.
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Re: 2 heads better than 1 - power porting E7TE iron.

Post by Carnut1 »

David Vizard wrote: Tue Nov 20, 2018 11:41 am
Carnut1 wrote: Tue Nov 20, 2018 10:45 am
CamKing wrote: Tue Nov 20, 2018 9:39 am

It will be a 268/222, .544" on 110
Will that be a hft or hyd roller? Thanks, Charlie



Hyd. roller.

Just had a call from Mike - good news - cam will be shipping today.
DV

Nice! I guess 390hp with DV/Charlie E7's with fixed quench and 32 degrees timing. Thanks, Charlie
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Re: 2 heads better than 1 - power porting E7TE iron.

Post by David Vizard »

Continuing my last post from page 36 which dealt with the discharge coefficients and how the curves can give a good insight ito where you need to make you next mods lets move on to the subject of port velocity. This is something that is almost universally accepted as important but very few head porters seem to have any idea what the numbers should be or, if they do, to pass them on.

Well here is some data that will fix that situation.

Take a look at the IOP graph shown below. Here are the mean velocity figures for RBJ Racing's head versus the stock head.

The thin lines are the stock head and the thick lines the RBJ head. Blue is intake and red ex.. What is the target velocity we should shoot for?
The way the IOP program deals with this we should be targeting about 290 - 330 in the intake and 300 to 350 on the exhaust. So lets see where we are.

First the intake.
As can be seen the velocity went up by a goodly amount. At the top of the lift range used by our baby 260 degree cam the mean port velocity on John's heads were up by over 26%. So the intake ports had a lot more flow and at any given lift, and more velocity. That accounts for the excellent torque output and the good top end power achieved without have to turn excessive RP{M.

As for the exhaust we can see the flow was gained at the expense of velocity.This indicates the port is too big and a more efficient but smaller CSA port needs to be sought after. That reduction on velocity means the scavenging effect is reduced and that can have a measurable effect on torque throughout the rpm range but more so at the low rpm used in street driving.

The increase in torque due to better scavenging at O/L and ramming at the end of the induction stroke is due to the increased velocity and air mass involved. In other words the kinetic energy it contains that, when slowed by a resistance can be turned into a higher pressure energy to better fill the cylinders.

and now we have broached the seemingly touchy subject of port energy I will show what the difference is between a stock head and RBJ Johns modified head. I will also answer the question of whether the increased exhaust flow was of grater benefit the the loss of velocity a detriment. Watch out for the flack and my next post.

DV
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Re: 2 heads better than 1 - power porting E7TE iron.

Post by Casper393W »

Well I'll get the Popcorn and kick back! This is very good info... Keep it coming
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Re: 2 heads better than 1 - power porting E7TE iron.

Post by randy331 »

RTercovich wrote: Sun Nov 11, 2018 10:12 pm One problem with software programs is that the program is only as smart as the person that designed it or the intelligence in which he/she chose to incorporate with the program. The flow bench falls into a "similar" category to a certain extent because tests are steady state and we all know that's a completely different story in a live engine. Programs and benches are great "basic" tools for "general guidelines" but if you are searching for more, you must dig deeper and twist your brain in a knot to find your finish line.
Guess it depends on where you currently stand on the engines you build.

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Re: 2 heads better than 1 - power porting E7TE iron.

Post by 68corvette »

Which of the heads had the biggest port energy?
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