Looking to build a 348 4” stroker........

taws697

taws697

Well Known Member
Hey guys. After attending the 348/409 drags in Earlville, I’ve been doing more research on a W motor build for my 63 Biscayne. This is what I’m looking to do....348 block, eagle 4” crank, forged rods and pistons, Edelbrock heads and intake manifold. I'd like to back it with an Autogear M23, beefier 2 piece driveshaft and a 9in. rear. I have zillions of questions!!!
First off, what 348 block would be best for a stroker as far as strength? Would this be a situation requiring a splayed 4 bolt main setup?
What compression ratio would I shoot for with aluminum heads on 93octane?
Has anyone used a needle scaler to texturize aluminum heads and paint them? Has anyone had headers coated in a cast iron looking color? I really enjoy the look of a factory engine for whatever reason.
Is 500 Rear wheel horsepower obtainable while still being streetable? (About 575 crank hp)
If running a 4.10 gear with a 28” tire, would a close ratio or wide ratio trans be a better set up?

Sorry, some of the questions may be off topic for this section. Any feedback is appreciated.
Thanks, Wes
 
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Phil Reed

Well Seasoned Member
Supporting Member 10
Wes.....did we meet each other???? Don't remember.

Call Carl Mcquillen in Leroy. NY!!!!!!! I was shown a dyno sheet at Earlville from one of our members, who started with 348 block and a 4" or 4 1/4" crank....440CI...that made insane horsepower!!!!!! I was blown away!!!! Made more horsepower than 409 blocks!!!! Don't know if he wants particulars known so I'm not saying more.
IT WAS AWESOME!!!!!!!!!!!
 
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Don Jacks

Well Seasoned Member
Supporting Member 3
Wes,Yes,it can be done.A 440 inch motor can be done from a 348 by boring it out .060 and using a 4 inch stroke crank.A fairly well ported set of Edelbrock heads,MQuillian intake,a roller cam in the 242@.050 range,a set of 2 inch primary tube headers and a compression ratio of 11-1 will get you there.A 962 X block or a 655 block are your best choices.4 bolt main conversion is unnecessary.Get with Carl McQuillian for the details,but your desired power levels are attainable in a streetable tune without having to go much past 6300 rpm on 93 octane fuel with careful tuning,but going to EFI would be the best and would have better street manners.You'd be better off going with an automatic because with this much power,it's going to need a strong aftermarket[expensive] transmission and a specialty clutch .Those parts are marginal as far as streetability is concerned.
 
Skip FIx

Skip FIx

Well Known Member
"You'd be better off going with an automatic because with this much power,it's going to need a strong aftermarket[expensive] transmission and a specialty clutch .Those parts are marginal as far as streetability is concerned. "

Why my 64 project is getting an auto. I had an extra semi built BOP TH350 we added an Ultrabell to mate to the Chevy motor.

Also I'm not sure on 348 blocks, but on my 65 409 block the main webs look thin where adding that outer bolt on a 4 bolt conversion if straight bolts would make it weaker.
 
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427John

Well Known Member
I can very much believe that an aluminum headed w motor built with good attention to detail especially to quench distance can tolerate 11:1 on pump gas.As far as the needle scaler creating an as cast texture on machined aluminum surface,I've never painted 1 afterward but have used 1 on a piece that I bead blasted afterward and couldn't tell it from surrounding as cast surfaces.If you do it on the machined ends of the heads make sure to round off the edges of the the flat area before using the scaler.
 
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Don Jacks

Well Seasoned Member
Supporting Member 3
No,Brian has many hours in tuning to find the sweet spot,and he doesn't have to put up with that 91 octane "Panther-Piss" they call fuel in your state,Mike.If he did,,you'd be right,he couldn't.
 
1964SuperStocker

1964SuperStocker

Well Known Member
Supporting Member 3
348 strokers are every poor mans magic potion. 4 inch stroke is no big deal and the aluminum heads are ideal but for the money and the power you are shooting for I would step up to BWR heads. Automatic is probably best and fuel injection is best too. Money is all it boils down to. Are you willing to spend what it takes to make 575hp? That is up to you. I built my 348 stroker with forged internals but saved money by going with a 454 crank. You could go the same route and have more money to spend on BWR heads. Earlville was a blast in my big family wagon project but my 64 2dr belair will get my stroker motor for light weight fun. :good
 
1964SuperStocker

1964SuperStocker

Well Known Member
Supporting Member 3
63 dream'n said:
Anything 348-409 = Stroker magic............not for the poor man.......:no$$$$$$$$$$:gaah
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Anyone can buy 348 blocks cheap. I paid $50 for the last one I picked up and haven't ever spent more than $500 for a complete engine. No one will deny a 409 block is always pricey in comparison so again poor mans magic is a 348 stroker as it directly relates to a 409. :D I have lots of friends that built their 409's for double what I paid for my 348 stroker.
 
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Skip FIx

Skip FIx

Well Known Member
CR and what can run on pump gas! A big discussion on my Pontiac board also. I know one well known builder on aluminum head builds limits them to 10.25 saying you never know what crap gas you will get and why take the chance of pounding the bearings if it detonates. I think I read a small % HP increase for every point of increased compression. And you can have detonation and not hear it! Some guys there swear they run over 10:1 with iron heads. Yes maybe with careful cam selection(big overlap to bleed off compression) timing, jetting. Mopar buddy running a wide band O2 meter saw big mixture swings between tanks of pump gas. You think the same blend is at every pump-especially if they legalize 15% ethanol??

When we dynoed my iron head Ram Air IV 400 10:1 we used pump gas for a few pulls-no audible detonation. Switched to race gas and picked up almost 10 HP. So it was obviously having some detonation and need for higher octane.

I'll try and pick up the HP loss form a slight decreased compression ratios somewhere else -or just deal with a a 10-20 HP loss.
 
1964SuperStocker

1964SuperStocker

Well Known Member
Supporting Member 3
Skip FIx said:
CR and what can run on pump gas! A big discussion on my Pontiac board also. I know one well known builder on aluminum head builds limits them to 10.25 saying you never know what crap gas you will get and why take the chance of pounding the bearings if it detonates. I think I read a small % HP increase for every point of increased compression. And you can have detonation and not hear it! Some guys there swear they run over 10:1 with iron heads. Yes maybe with careful cam selection(big overlap to bleed off compression) timing, jetting. Mopar buddy running a wide band O2 meter saw big mixture swings between tanks of pump gas. You think the same blend is at every pump-especially if they legalize 15% ethanol??

When we dynoed my iron head Ram Air IV 400 10:1 we used pump gas for a few pulls-no audible detonation. Switched to race gas and picked up almost 10 HP. So it was obviously having some detonation and need for higher octane.

I'll try and pick up the HP loss form a slight decreased compression ratios somewhere else -or just deal with a a 10-20 HP loss.
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Just using higher octane fuel doesn't specifically mean detonation is only cause to decreased HP does it? Was it "Switched to race gas..." and adjusted timing or jetting or plug gap...? Just trying to understand how you would adjust a motor to run and then switch to race gas and pick up 10hp without first determining that your tune was likely wrong in the first place before the race gas was used. Am I thinking about this right? You could have backed your timing down and it would have no detonation that you discovered you likely had once race gas was used. Thanks for any feedback.
I had a crappy tune going at the track before I raced and thankfully my crew stepped in and made adjustments based upon experience and not what a text book prescribed.
 
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Don Jacks

Well Seasoned Member
Supporting Member 3
I could be wrong,but I'm thinking that when e-15 becomes the prevelant fuel,we'll have to convert them to efi in order to live with these older cars.Carb's and e-15 will likely be more trouble than it's worth.Some of the older 4gc's have to have extensive work just to run decently on e-10 as it is now.E-10 doesn't have a detremental effect as far as detonation is concerned as long as the fuel mixture is right for the fuel being used,but getting it right can cause you to rethink what you've always done before.
 
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427John

Well Known Member
Yes the higher the alcohol content of the fuel will reguire more fuel flow due to the lower btu content.The guys that run straight alcohol in their race motors have to build their fuel systems with at least double the capacity of an equivalent gas engine.While I don't believe higher alcohol content will require all carbs to be abandoned,I agree that the possibility of even more inconsistent blends will cause a situation that lacking an O2 sensor along with an on the fly adjustable jetting system will make them more trouble than their worth(bordering on unmanageable).Instead of the current worst case scenario of swings in blend from 0-10 you could see 0-15%.This would only apply to people that put lots of miles on their cars,owners of occasionally used cars or race only rigs will probably be only too happy to buy ethanol free or race fuel to avoid those issues.
 
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tenxal

Well Known Member
Skip FIx said:
When we dynoed my iron head Ram Air IV 400 10:1 we used pump gas for a few pulls-no audible detonation. Switched to race gas and picked up almost 10 HP. So it was obviously having some detonation and need for higher octane.
Click to expand...

Not necessarily detonation.....depends on the combustion chamber design/shape, plug location, total quench area and volume, how far down the top ring is, etc.

Plus a lot of other things we can't control or predict when we build an engine. ;)
 
Skip FIx

Skip FIx

Well Known Member
Had a lot of pulls timing, jetting before we did the switch. RAIV chambers open compared to other Pontiac chambers 0 deck.

Just saying 10:1 and iron heads will probably need more octane than 92 variable blend gas at the pump. And that there can sure be inaudible detonation that can hammer bearings.
 
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