# 326 stroker



## RunninLeMans (Apr 3, 2014)

Okay, I know the general wisdom is to invest engine dollars in a block with big holes since it costs about the same to build a 400 or 455 as a 326 and you get more HP and torque for the buck.

But, just as a hypothetical exercise, since we all like to dream about motor builds, if a Tempest/LeMans enthusiast wanted to keep his 326 block and retrofit a Butler 4.25" stroker kit, the result would be a very over-square motor of about 380 cubes. What would you do for cam grind, intake/carb, etc. to compliment this long-stroke motor? Seems like it would be more like a truck motor, lots of low-end pull and done at 4 grand.


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## geeteeohguy (Feb 2, 2008)

There is an excellent article in HPP magazine, maybe two years back, where they built a 350 engine similar to what you're describing. It made a ton of power....something like 440 HP, if I remember correctly. Search it out. Back in the old days, ALL engines were under-square. Because most were L-heads, it worked out fine. Even the overhead valve Nashes, Buicks, and Chevrolets had long stroke engines. I've owned several, and I can tell you, they are very easy to drive---pulling top gear from walking speed to top speed without lugging. I think for the price of the rotating assembly, though, you'd spend more money on the 326 then on a 400, where everything is readily available. 326's are excellent engines, though: cool running and long lived. A TON more torque than a 327-350 Chevy in every case, too.


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## RunninLeMans (Apr 3, 2014)

Thanks for the heads-up, here it is:

Small-Bore Pontiac Performance Engine Build - Revenge Of The 350

This motor looks like a $6K-$10K build to me, with a pretty radical cam, out of my budget and not suited to my purpose. 

When thinking about my next engine (yes, there will be another engine!), my pendulum swings back and forth, 95% of the Pontiac performance enthusiasts say start with a 400, or at least a 389, for the best HP/$ result, and I get that. Then there are a few stragglers who want to keep the smaller-bore block for their own reasons, usually originality. I asked the question because a 3.75" bore and 4.25" stroke seems so unusual, I'm curious how it would perform and I like the idea of doing something different. My gut tells me this would be a real stump-puller, which would be suited for an automatic car with a moderate gear. Still, $1,900 just for the rotating assembly is a chunk for an experimental engine....


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## jmt455 (Mar 26, 2012)

Did you see the PY Forum thread on the 383 stroker 301?
It was about a 2-year project.
I thought it was a fascinating thread.

Here's a link to one of the last pages (with posted dyno sheets):
301 stroker build - Page 17 - PY Online Forums

Peak HP 475HP @ 6000 RPM
Peak Torque: 438 lb.ft. @ 5300RPM

That engine was for sale a while back on racingjunk.com
Seller was asking $5000 for it.
The ad expired a cpople of months ago, but you can still see it here:
pontiac 383 stroker 301 engine for sale for Sale in LONG BEACH, CA | RacingJunk Classifieds


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## geeteeohguy (Feb 2, 2008)

Your gut is right, runnin'. You would have a very tractable, durable and economical high torque, low rpm engine. It would be great with a 2.56 or 2.78 rear gear.....and probably get 25 mpg on the open road, too.


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## Lemans guy (Oct 14, 2014)

I think it is an interesting discussion as well. GEETEEohguy is right about the surprising torque of the 326. Also how cool it runs. I like you runnin like it in the low RPM's anyway that is where I drive it, just a cruiser really.

But I like mine real peppy. I pass Butler every now and then they are just south of Nashville. I think Geeteeohguy does understand the 326, many just dismiss it. That said the 400 parts and all around stuff should be relatively easy to obtain for years. The 326 had only 4 years of production.

The 326 is good on gas and the 400 would be a little worse of course, and they could both operate strong in the low RPM bands.With the 400 you could keep it closer to stock than all the big stroker kits if don't need or want it.

running, don't forget your timing curve on that 326, really makes a difference when you set it right,,,:rofl::rofl::rofl::rofl:


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## RunninLeMans (Apr 3, 2014)

I talked to one of the stroker kit guys, just to satisfy my curiosity. I assumed the long stroke/small bore would like a high-lift/short duration cam profile. He said that might not be the case, as the smaller bore shrouds the valves, limiting air flow, the higher lift is wasted but it might like some duration. An old-school 067 might be just the thing....

LeMans Guy - Not to get sideways on the topic, but on the timing curve - I'm running about 14 initial and 35 total, my last stab at the springs I had one medium and one soft and it still wasn't all in until maybe 3,500 rpm, so next time I'm fussing with it I'm going back to two soft springs. How'm I doing? Any advice appreciated.


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## Lemans guy (Oct 14, 2014)

runnin, I go right from Lars timing 101 paper, you can find it easy on the web. He is the guy who knows and I follow his advice on it.

Here is what I do, I got a B-28 Distributor vacumn can from auto zone. It pulls in 16 degrees of advance with about 6 or 8 inches of vacumn. I use that can because I use full manifold vacumn at idle.

there are three timing settings'

Mechanical....use set when you turn the Dizzy and lock it down.
Vacumn...which you get off the Can
Centrifigal....which is your weights

Vacumn is load sensitive by your foot and centrifigal is ONLY rpm sensitive

So I run 10 mechanical, 16 vacumn, and 26 Centrifigal 

Total advance is only Mechanical and Centrifigal because it is the total you get at WOT, since you get no vacumn then....

So Total is 36 Degrees, but the majic is all in the 16 degrees vacumn as it responds to your demands....it makes a smooth idle at 26BTDC

Now when I put my Tech 2 on a modern Chevy, I can see those kind of advanced at idle. But the computer does it.

Try that B28 vac can, full manifold vacumn, about 8 to 12 degrees mechanical the rest centrifigal you want 52 degrees with all three.

I get all three at light throttle cruise, which is about 50 horse power, I watch my vacumn gauge and RPM gauge.....

It will make it run so sweet, and feel so powerful. Read Lars paper and you will get it. If it pings you turn it back a few degrees. We set up my friends 64 corvette with the right curve, what a difference.

you goota run vacumn advance the right way or you are missing lots of free adjutable performance.:rofl::rofl::rofl::rofl::rofl:


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## Lemans guy (Oct 14, 2014)

PS sorry yes I agree try two light spings all in as quick as you can...... and try it...

you have to see how it responds...a doggy vacumn can won't help 

and they only cost $13......best upgrade for the money!


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## RunninLeMans (Apr 3, 2014)

Took me a day of free time to read through the 301 stroker thread. Holy crap, 479 hp from a short-deck 301 block, that's amazing! Damn, wonder what I'm going to do...


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