371 build W/Big Mouth heads

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jimjimjimmy said:
Jesse did you do any blending or are these heads the way they came from Hugh's the reason I ask is would the shitty short side help cause the low end power below 4000 you speak of .
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Believe me I "helped" these heads a ton with extra care blending the bowl/throat, trick valve job, there was a gouge in the short side that I did my best to remove/lessen, pushed S.S. back as much as I dared to "stand it up" etc....

To answer your question YES a proper S.S. would bolster the flow numbers and hence velocity in the lower lift ranges which would probably pick up the torque 30-40 points below peak torque. I pulled this engine down @ 3500-6800 once just to see and its weak 380 ft/lbs--it also sounded and acted really bad. J.Rob
 
B3422w5 said:
They designed W2/5 stuff for stock stroke motors.
No eddie type head will ever be too big for a stock stroke smallblock that is making any steam at all.
Modified or not, they are still just a factory replacement head.

Wide LSA cam might or might not look good on the dyno, but i can almost guarantee you any car its put in will be a dog out of the gate. Been there done that with 112 stuff in a smallblock drag car that isnt a lightweight gutted ride
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Totally possible but this isn't aimed at a drag type build--more of a street/autocross/roadcourse. J.Rob
 
rumblefish360 said:
So sorry, can you explain this?
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Darin Morgan talks about it a lot. Its basically a ratio of flow vs curtain area and valve size. Basically if you have a 2.02" valve that flows 280 cfm and you move up to a 2.05" valve and it flows 281 cfm you will most likely lose power and a bunch of it. So if you move to a 2.05" it better move a proportionally greater amount. So with these heads flowing a whopping 284 with a 2.08" it has a very poor discharge co-efficient. If you search Speedtalk you will see this and the math behind it discussed a lot-and it absolutely works. J.Rob
 
Sounds like there previous “BM” head was better.
 
You even surprised yourself, best part of the hobby.
Ironmike knows what the numbers could be with a 4" arm, a different cam though ..he would not. You could guess the wider lobe would bring the hp/tq closer together.. however with one moving more than the other. I had forgotten they used 2.08, in effort to keep it together. Ouch. I'd guess the eq' s weren't or wouldn't be as dirty down low, which intake manifold was it? You could do better if the short turn was yours to modify...but the pic of the BM bowl I have seen looked like a light bulb. I've been so busy though.. I can't remember.

stixx said:
Well, his last 371 [published] made 540 HP @6800 and 492 (?) TQ @5100 with max ported EQ heads, IIRC.
We'll see.
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RAMM said:
Found my flow notes from last year. J.Rob

View attachment 1715022871
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RAMM said:
Good memory--in all honesty I doubt these heads will reach that. J.Rob
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RAMM said:
??? J.Rob
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In regards to the sft cam, nothing wrong with it...in fact it bled the heads for all they had.
Had it been ground specifically for them there could be more, could mostly be torque gained. But more so with another head, It is interesting. Thanks for taking the time to post it.

So much has been done, not all documented for us to see. Sure people hide their specs... but unless you completely mirror image every detail , well ... I don't worry about giving out my specs and yeah it idles great with a 4 spd, though its a roller anyhow. But it's the reason I gave a 550 guess...similar'ish .The flow numbers are only a hair lighter than mine but your cid makes those heads big in this case.
I could understand if someone had built the best combo on the face of the planet woth parts everyone could get their hands on or easily emulate... but this isn't the case for me, not the accumulation of all I've learned... more of a back lash towards over priced cylinder heads, though I'm very happy with it.

.575
287
251
104 int cl
108 Lsa
S. Roller

It's always interesting to see the way people go after hp and what they know in order to exploit what they have.
 
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RAMM said:
Both. When it idles @ 1150-1200 rpm it surges like it has a blower on it. Retarded amounts of reversion. J.Rob
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That highly technical term 'retarded' made me laugh LOL
Any VE numbers that can be shared? (I think they are cut off to the right hand side of the sheet....)
 
nm9stheham said:
That highly technical term 'retarded' made me laugh LOL
Any VE numbers that can be shared? (I think they are cut off to the right hand side of the sheet....)
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Sorry no VE numbers yet because I didn't even take the 10 seconds to install the air turbine. I bet its 104-105% though. I plan to record all of that and idle vacuum as well. This wil be important when I swap cams. J.Rob
 
Are you going to run a vacuum advance distributor?
 
RAMM said:
Sorry no VE numbers yet because I didn't even take the 10 seconds to install the air turbine. I bet its 104-105% though. I plan to record all of that and idle vacuum as well. This wil be important when I swap cams. J.Rob
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OK, I just like to see those numbers. Thanks!
 
RAMM said:
Sorry no VE numbers yet because I didn't even take the 10 seconds to install the air turbine. I bet its 104-105% though. I plan to record all of that and idle vacuum as well. This wil be important when I swap cams. J.Rob
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I'm guessing 107.33333333333333%
 
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The current plan for this engine is to re cam it and I am on the hunt for a Weiand X-celrator manifold part # 7545 or 7510. I'm hoping to send Tarzan to etiquette school and give it some manners with equal or superior power. Im not sure if this is really possible but am willing to try. This engine is just so good. This week I put Hedman truck headers on it which feature smaller primaries and a 3" collector as opposed to the dyno headers of 3.5" collector. As expected it added a boatload of torque under peak and sacrificed about 10HP at the top. So as it stands I have 28 dyno pulls on this including the 5 x 5 min break in cycles and it never makes less than 540 hp/475 tq. Really attached to this thing at this point. In addition to the cam and intake change I will also can the locked out timing curve and put a proper distributor in. Currently trying to upload a video of a test I did today to Youtube. J.Rob
 
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