383 rotating assembly's

[jims56]

Looking for 383 rotating assembly suggestions. Looking to turn my L31 vortex 350 into a 383. Use the stock 64cc heads, it's a newer crate motor with 7000 miles on it now. Will be a street driver. What i read read so far scat comes in first am I wrong here?
Jim

[markm]

I have never bought an assembly, but have had good success with their cranks. Great choice in wheels Jim.

[jims56]

Thanks markm.

[56ls408]

Thanks markm.

used they're 3.75 crank & I beam rods in a 383 balanced well no issues I felt the rods were a nicer set than Eagle's I beams also used a set of I beams in a small journal L79 327 in a 65 vett i had another company that isn't heard a lot from is Molnar Technology Tom Molnar was the lead designer at Oliver rods then started K1 later sold the company to weisco but ran it for 5 years because of a no compete contract then started his own company several years ago like Eagle Scat & even Callis lower end forgings are offshore but 100* of the machining is done in-house to very high standards I have his crank & rods in my 408ls3 plus if you call he's who you talk with prices are in the same range

[BamaNomad]

that's the definitions I've always used as well, Mark... A 'dish' piston ADD volume to the combustion chamber, whereas a domed piston reduces the combustion chamber volume.

What was bothering me was Mike55 stated intention to use 12cc dish pistons and getting a CR close to 10.5... I thought the CR would be much less than that (but I was thinking of a 350 ci engine.. Mike55 was referencing a 383.. so I went into my Compression Calculator and increased the stroke to 3.75 and the bore to 4.030 to get the 383 cid, and sure enough a (-)12 cc DISH piston with 64 cc heads, 0.020 deck height, 0.016 gasket (steel shim) will result in a chamber volume of 5.10 in**3 and a static CR of around 10.4...

So Mike please excuse my confusion, as I have never built a 383 and wasn't thinking about the additional 1/4" stroke and it's effects.. I think the use of DISH pistons in such an engine very likely is one of the reasons that those engines are so powerful!

PS. I've got a std 350 block (with bad forged crank) in my basement.... maybe I should consider buying such a 383 stroker kit for it..

[markm]

that's the definitions I've always used as well, Mark... A 'dish' piston ADD volume to the combustion chamber, whereas a domed piston reduces the combustion chamber volume.

What was bothering me was Mike55 stated intention to use 12cc dish pistons and getting a CR close to 10.5... I thought the CR would be much less than that (but I was thinking of a 350 ci engine.. Mike55 was referencing a 383.. so I went into my Compression Calculator and increased the stroke to 3.75 and the bore to 4.030 to get the 383 cid, and sure enough a (-)12 cc DISH piston with 64 cc heads, 0.020 deck height, 0.016 gasket (steel shim) will result in a chamber volume of 5.10 in**3 and a static CR of around 10.4...

So Mike please excuse my confusion, as I have never built a 383 and wasn't thinking about the additional 1/4" stroke and it's effects.. I think the use of DISH pistons in such an engine very likely is one of the reasons that those engines are so powerful!

PS. I've got a std 350 block (with bad forged crank) in my basement.... maybe I should consider buying such a 383 stroker kit for it..

ar

No problem, I have damn near come to blows with friends who are mechanics with 40 plus years on the job who either think a 64 cc head on a flat top 283 is 10-1 or a flat top 454 is 10-1

[55mike]

So.... now that are all singing from the same hymnal, has anyone used the CompCams XE274 in their 383?

[BamaNomad]

There may have been a change/modification in terminology since the days long ago when I spent more time on engine configurations; mostly these days I lean towards running 'factory stock' (but hopefully high performance) engines on the street. I never heard the term 'dish pistons' until the factory began to reduce compression and kill performance (mid-late 70s). Dish pistons were used to increase compressed volume and reduce compression in those motors.

I just searched for and found a fairly good article (by Wiseco - a piston mfg) which explains significant detail related to piston crown design.

https://www.hotrod.com/articles/insi...ons-explained/

Obviously the piston crown design is complicated and varies by what type of engine and induction is planned. He makes a statement, which should be obvious, that most desirable is a 'flat top' piston, because the maximum combustion force is directly applied to downward motion of the piston. You have to think about head combustion chamber shape/volume, quench, head gasket thickness, etc when choosing your pistons (or let the engine builder choose it for you based on your objectives).

[55mike]

I'm going to build a 383 in the future. My plan is to use 12cc dish pistons, with my AFR 190 heads that have been decked to achieve 64cc chambers. The plan is to have about 10.5 to 1 compression (might be a touch higher). The block is a seasoned 350, 2 piece rear main, and I'll use a flat tappet camshaft. I'm planning to use a CompCams XE 274 camshaft. My question to the forum is, has anyone used the CompCams XE 274 in a 383? Comments about the XE 274...?

[jims56]

That's my plan also to use the +12cc piston.

https://www.summitracing.com/parts/esp-b13504l00053