[hurryinhoosier62]

Originally Posted by Squidward

68azbird made a valid statement. He was legitimately exploring this exact scenario, because I have the 350 engine that he was going to use as the foundation. But when it comes down to the nuts and bolts and dollars, the project made less sense from a practicality point of view.

Does anyone have a realistic projection on what the stroke increase would get you? It amounts to a relatively small increase in stroke, assuming 3.75 to 4.00. What would be the estimated percent bump in power?

Tom S. got 480hp out of a 301T block based 388. Considering a 350 block is much stronger than a 301T block, 500+hp out of a stroked 350 with the correct heads, induction system and cam wouldn’t be out of the question.

[Sirrotica]

If someone builds a stroker 350 In my opinion they have to have a goal in mind to make it feasible. If you want to run heads up in a class that has say a cubic inch limit and you're going to be going head to head with a SBC, ford or mopar you're probably going to be the underdog fighting an uphill battle.

Now an application that needs low end torque from the basement, up to say 6000 RPM, and has a cubic inch limit you may have an advantage.

The Hudson engine was an undersquare engine and was the engine to beat until 1955 because they wouldn't go to an OHV configuration. The early bore and stroke was 3.5625 x 4.375-inch bore and stroke were enlarged to 3.8125 x 4.5 inches, totaling 308 cubic inches. So here you have a 4 3/8 stroke lengthened to 4 1/2 inches. Small bore with a huge disadvantage of a flathead configuration that beat the OHV olds and Cadillac V8s regularly. The Hudson was also an inline 6 to put it at a further disadvantage. Read up on the Hudson flathead 6 to get a little perspective on how competitive it was.

IMO, you'd have to have a specific use in mind to make a stroker 350 Stratostreak engine practical. I'm not sure what application it would be, maybe a truck, or a pulling engine with low end. The OP has not eluded to what he would use the engine for????

[ponjohn]

Stroke a 350 to 388 then a pair of turbos.

[RocktimusPryme]

Originally Posted by ponjohn

Stroke a 350 to 388 then a pair of turbos.

Stroke a xxx to xxx then add a pair of turbos.

That last part is pretty much a recipe for success is almost any combo.

[ponjohn]

Originally Posted by RocktimusPryme

Stroke a xxx to xxx then add a pair of turbos.

That last part is pretty much a recipe for success is almost any combo.

Correct but my thought was the smaller bore would allow the HG to live.

[tom s]

Actually 383 as I remember but im old.It was a 3.75 stroke and I think a 4.030 bore BUT!Everything was shorter,6ish rods,1 in shorter push rods etc.NO reason 60 over 350 cant do pretty much the same thing with a single plane intake,and like cam and you DONT have to do the stroker.HP is in the heads,they floed 260@600 and had a cam and intake that complemented them.FWIW,Tom

[67GTO4SPEED]

Originally Posted by hurryinhoosier62

Tom S. got 480hp out of a 301T block based 388. Considering a 350 block is much stronger than a 301T block, 500+hp out of a stroked 350 with the correct heads, induction system and cam wouldn’t be out of the question.

I've always thought (based on info from people here) that the 301T block was as strong as normal 350, 400 blocks? The 301T has a .125" bigger bore too.

Not saying a 350 couldn't make 500 HP (people have done it) but it wouldn't be as easy as getting it of a 301T block.

[67GTO4SPEED]

Originally Posted by JLMounce

In a normally aspirated build, I kind of agree that even a 557 block 400 would be a better candidate. What I've always wondered about however is the 350's potential for a boost (specifically turbocharged) build. You overcome some of the engine's pitfalls like it's small bore when you start force feeding it.

I bounced that idea around before. I have a good running '73 350, a Demon 650 blowthrough carb, and a pair of 301T manifolds! I've thought about throwing an eBay turbo on there and keeping boost low around 6-8 lbs.

[Squidward]

OK, so it begs the question: Maybe a boosted regular 350 instead of a NA stroker?

Butler's website shows "Not Available" for the cast 4.00" crank. It's $340, and has BBC rod journals. Forged custom pistons are going to be required any way you slice it because there are no off the shelf 350 forgings. So what are we looking at in cost JUST to do a NA stroker? From Butler, $2400 for 4.00" kit, and $1900 for 4.25" kit. But even going cheapo(?) ala carte, It'd be $500 for pistons, 240-340 for crank, 440 for rods, 100 for rings, whatever bearings go for these days. Add another $200 for balance.

If I wasn't an average Joe and had $$$ to throw at being eccentric and odd, I'd consider a stroker. Or I'd sooner consider using these throwaway 350's as test fodder on a boost project, since it would bolt in place of other CID's.

[Sirrotica]

2002 Hot rod article says B Flopper built a .060 350 that made 540 HP. Not many specifics though.

[67GTO4SPEED]

Originally Posted by Sirrotica

2002 Hot rod article says B Flopper built a .060 350 that made 540 HP. Not many specifics though.

Oh yeah. That's the infamous 87 octane 350 that destroyed the need for anybody to ever build a 400 stroker, according to Flopper...

[hurryinhoosier62]

Originally Posted by 67GTO4SPEED

I've always thought (based on info from people here) that the 301T block was as strong as normal 350, 400 blocks? The 301T has a .125" bigger bore too.

Not saying a 350 couldn't make 500 HP (people have done it) but it wouldn't be as easy as getting it of a 301T block.

Tom S. and I have had a few conversation about his 301T build. The late Joe Sherman rated the 301T block to be as strong as an SBC block, The Pontiac 350 bore is nearly the same as the LS 346 engines. 3.905 is a standard oversized for LS pistons. Bore a 350 block to 3.905 with a custom piston based on the LS piston ( very light), add in the 1.5/1.5/3.0 mm LS ring pack and light LS style pins. Add a 4.00 stroke 3” main crank with a set of good forged rods and you’d have the makings of an excellent street engine with more than enough horsepower and torque to surprise the 400 and 455 guys.

[hurryinhoosier62]

Originally Posted by tom s

Actually 383 as I remember but im old.It was a 3.75 stroke and I think a 4.030 bore BUT!Everything was shorter,6ish rods,1 in shorter push rods etc.NO reason 60 over 350 cant do pretty much the same thing with a single plane intake,and like cam and you DONT have to do the stroker.HP is in the heads,they floed 260@600 and had a cam and intake that complemented them.FWIW,Tom

Well said, Tom! People are spending too much time saying it can’t be done instead of looking at the real world possibilities. Too bad Paul Carter couldn’t get five interested people to buy his proposed LS based pistons from CP/Carrillo. They would have been the basis for one hell of a street engine...You’re correct, 383. I don’t recall why I thought it was a 388.

[unruhjonny]

please guys, don't drag this discussion down with any posts suggesting flopper;
he has proven time and again to be the scourge of the Pontiac commuinty.

Also, 301T exhaust manifolds won't work on a head for anything other than a 301/265...

Am I the only one here who seems to recall that there was an HPP article where an "off the shelf" forged 318(?) piston was used for the rebuild??

[Sirrotica]

I don't believe anyone suggested him, I cited a hot rod article that he built one, and they featured his engine in it, and they said it made 540 HP NA, that's it. I would never suggest anyone use him for any type of a build.

[ponyakr]

"...Forged custom pistons are going to be required any way you slice it because there are no off the shelf 350 forgings. So what are we looking at in cost JUST to do a NA stroker? From Butler, $2400 for 4.00" kit, and $1900 for 4.25" kit. But even going cheapo(?) ala carte, It'd be $500 for pistons, 240-340 for crank, 440 for rods, 100 for rings, whatever bearings go for these days. Add another $200 for balance..."


Looks to me like the price for a 350 stroker assembly is almost exactly the same as for a 400 block stroker. If not, what's different ?

So, looks to me like a 350 stroker will be cheaper, by the difference in the cost of the block. Even if you're one of the guys who has hoared up lots of 400 blocks, for an honest assessment of the cost of a 400 block stroker build, you would still need to consider how much you could sell the block for. I think there are probably lots of guys, in some areas, who would give $500 or more for a good 400 block that will safely bore .030.

But, I'm not saying that a 350 stroker will make as much power as a 400 block stroker. BUT, I think it has been proven beyond any shadow of a doubt that 450-500 streetable hp is easily available.

Everybody today seems to want 600hp on the street. We had lots of fun & won lots of bracket races with only around 400hp & less, running 12's & high 11's. I figure a well built 350 stroker would easily make a very streetable 400hp, without having a crazy cam or high compression. And, because of having less low end torque than a 455+, it should be a little easier on parts, such as trannies & rear ends.

But, some are going to put down any build using a 350 block, no matter what. So, I reckin it's not much different than a cam thread. We are not all gonna agree.

[ponyakr]

Byron McElfresh did a 350 block build for an Engine Masters Challenge, one year. I think he made well over 500hp. I had a link to an article about it. But, the link no longer works.

But, for anyone who is really interested, I'm sure he'd be glad to tell you all about the build. He seems like a really nice guy.

He started the Pontiac Drag racers FB page.

https://www.facebook.com/groups/pontiacdragracers/

https://www.facebook.com/byron.mcelfresh

[72LuxuryLeMansLa.]

Originally Posted by tom s

Actually 383 as I remember but im old.It was a 3.75 stroke and I think a 4.030 bore BUT!Everything was shorter,6ish rods,1 in shorter push rods etc.NO reason 60 over 350 cant do pretty much the same thing with a single plane intake,and like cam and you DONT have to do the stroker.HP is in the heads,they floed 260@600 and had a cam and intake that complemented them.FWIW,Tom

I'm certainly no expert but I would fall into this camp....

[Squidward]

Originally Posted by ponyakr

Everybody today seems to want 600hp on the street. We had lots of fun & won lots of bracket races with only around 400hp & less, running 12's & high 11's.

Well stated. I don't know exactly when the bar got raised so much for street motors. Somebody could easily build a 350 now that would've embarrassed some 400's and 455's from 30 years ago.

So in determining best bang for buck in a 350 based build:
1. Stroke 350
2. Put awesome heads on a 350 and make it run with 3.75 stroke
3. Boost with single turbo

I know that each of these plans aren't equal in cost or power potential, but it is food for discussion!

[ta man]

Originally Posted by Squidward

Well stated. I don't know exactly when the bar got raised so much for street motors. Somebody could easily build a 350 now that would've embarrassed some 400's and 455's from 30 years ago.

So in determining best bang for buck in a 350 based build:
1. Stroke 350
2. Put awesome heads on a 350 and make it run with 3.75 stroke
3. Boost with single turbo

I know that each of these plans aren't equal in cost or power potential, but it is food for discussion!

I like the turbo idea...buy up all the unwanted "Grandma" driven 350's and turbo them!