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I thought I’d post this for the simple reason stated above, something a little different.
One of my upcoming builds is, drum roll please, a turbo charged 455 for a 1976 23’ GMC Motorhome!
Custom Racetec .040 over 2618 pistons, 40cc dish, 8.4:1
New Gen III Edelbrocks
Hyd roller
Edelbrock O4B intake(scrapping the stock low profile iron one)
Terminator X TBI set up for flex fuel
For right now we’re going to try to use the previous manifolds and turbo setup that was on it when he bought the vehicle. We’ll see.
I tried talking him into doing a big block Stroker, low compression that he could run on 87 octane anywhere. But he was pretty hell-bent on using the unit that came with a vehicle. So, here we are. It’ll be a little while before I get it on the dyno, but any progress I’ll post here whenever possible.
Thanks guys!
Last edited by cutlassefi; Nov 13, 2024 at 05:11 PM.
Mark, what are your HP TQ goals? How much boost? Is the turbo a recent design or from one of those '80s kits that were the rage back then, especially for SBCs.
Mark, what are your HP TQ goals? How much boost? Is the turbo a recent design or from one of those '80s kits that were the rage back then, especially for SBCs.
It should make 400hp-500tq on motor only. Boost is going to be held to 5#’s or so. Not going to push it. I don’t think the turbo is very efficient anyway.
Just a thought and sharing a moment. The other day I heard what could have been the whine of a supercharger coming from a Dodge Challenger across the road from me at an intersection but the hood was original and I suspected there was no room for one so I thought, "maybe it's a turbo, they whine sometimes like that too". As I crossed the road and drove by the guy I notice his window was down and hollered "Spin it up!" as he started to take his turn crossing. So he did and man did he light up the tires! What a show! Maybe it was a turbo, maybe it wasn't.
Just a thought and sharing a moment. The other day I heard what could have been the whine of a supercharger coming from a Dodge Challenger across the road from me at an intersection but the hood was original and I suspected there was no room for one so I thought, "maybe it's a turbo, they whine sometimes like that too". As I crossed the road and drove by the guy I notice his window was down and hollered "Spin it up!" as he started to take his turn crossing. So he did and man did he light up the tires! What a show! Maybe it was a turbo, maybe it wasn't.
I bought a supercharged roots type 455 from a GM motorhome that was locked up. It had a B&M style 177 on it. Same type of build you are doing with the engine, gen 2 edelbrocks and it was nearly new.
It over heated badly and warped one head and caused it to lock up. Be wary of a supersized cooling system.
Subscribed, interesting.😊. Could we possibly get some photos of the GMC itself? Those things are all over the map with regards to quality. I’ve seen both stunning versions as well as “Cousin Eddie editions”
Last edited by Funkwagon455; Nov 19, 2024 at 03:51 PM.
Close to dyno time;
Updated specs;
8.8:1 comp
Cam 227/234@.050 on a 113lsa
It'll be dyno’d NA first with an Edelbrock 750 VRS Carb.
Anyone want to guess power with manifolds? Headers?
Thanks.
Spill the beans, man! What's the scoop on those lifters, especially compared to the Comp evolution? Anyone else notice sizing variances with the Comp Evo or is it just me?
Spill the beans, man! What's the scoop on those lifters, especially compared to the Comp evolution? Anyone else notice sizing variances with the Comp Evo or is it just me?
It's been a few years so my memory is foggy. I'm pretty sure there was more than 1 thou variance between lifters in diameter and they were an extremely tight fit.
It's been a few years so my memory is foggy. I'm pretty sure there was more than 1 thou variance between lifters in diameter and they were an extremely tight fit.
you said the Comp evo’s have variances….now you say it’s been a few years and your memory is foggy? The evo’s are a new design.
Why bring up Crane… are they even around anymore?
if you’ve ever measured the lifter bores on an Olds, you would know they are all over the place. The lifter dimensions are the least of your problems
you said the Comp evo’s have variances….now you say it’s been a few years and your memory is foggy? The evo’s are a new design.
Why bring up Crane… are they even around anymore?
if you’ve ever measured the lifter bores on an Olds, you would know they are all over the place. The lifter dimensions are the least of your problems
Evo’s have been out AT LEAST two years, maybe a bit longer.
And Crane was absorbed by Comp, at least part of it.
Bill Gaterman (Gaterman lifters) worked at Crane for years, as did Brad A. Miller, founder and owner of BAM lifters. Each of them bought machinery and programs from Crane once they closed their doors.
Last edited by cutlassefi; Jan 1, 2025 at 06:09 PM.
Evo’s have been out AT LEAST two years, maybe a bit longer.
And Crane was absorbed by Comp, at least part of it.
Bill Gaterman (Gaterman lifters) worked at Crane for years, as did Brad A. Miller, founder and owner of BAM lifters. Each of them bought machinery and programs from Crane once they closed their doors.
I don’t want to clutter up your thread with hearsay on variances..how about you start a new one to clear up the variance claim.
I never said anything about variances, you and oddball did.
I never said you did..you have an overactive imagination. even through this is your thread, you butted in to answer a question I asked of someone else …with a bunch of name dropping that meant nothing.
the fact is, there are no variance problems with the evo’s, for the Olds or any others.
Yes you did. you have a habit of not reading your own posts. I never said anything about variances, I just stated the Evo's have been out for at least 2 years. "I don’t want to clutter up your thread with hearsay on variances. how about you start a new one to clear up the variance claim".
This was directed to me for some reason, not oddball. YOUR post, #25. Get it?
Last edited by cutlassefi; Jan 2, 2025 at 05:14 PM.
Yes you did. you have a habit of not reading your own posts. I never said anything about variances, I just stated the Evo's have been out for at least 2 years. "I don’t want to clutter up your thread with hearsay on variances. how about you start a new one to clear up the variance claim".
This was directed to me for some reason, not oddball. YOUR post, #25. Get it?
exactly…I ASKED you to start a thread about the variance claim because you responded to my question to another person about a variance claim…understand?…I never said you SAID anything about variances…
I never asked you anything..you were being a Karen like usual..nobody asked who worked where or when or who does what with who . you went right into the drama .
Preliminary base numbers.
Remember it’s getting a TBI unit so I didn’t spend a lot of time tuning it. However air/fuels were pretty good, high 12’s to 13 or so.
I’m still trying to convince him to bag the turbo route, but we’ll see.
Last edited by cutlassefi; Jan 21, 2025 at 03:17 PM.
Final numbers were 452hp, 521tq (corrected) with the Terminator TBI. I’ll post the dyno sheet in a few.
Better yet I was able to talk him out of the turbo. I’ll explain more on that as well.
And yes, all done on 87 octane, and a 2.500” exhaust, just like he’s going to run.
Last edited by cutlassefi; Mar 11, 2025 at 08:48 AM.
Final numbers were 471hp, 524tq with the Terminator TBI. I’ll post the dyno sheet in a few.
Better yet I was able to talk him out of the turbo. I’ll explain more on that as well.
Very nice low compression 87 octane combo !
He could always throw NOS Cheater plate on and some 93 octane for the RV drags !
j/k
Last edited by GEARMAN69; Mar 13, 2025 at 08:03 AM.
