Pros and Cons of a 393 stroker

[bluevenom867]

Take a 100,000 mile piston (w/ oil ring intersection) and one without. Driven the same...

I promise you the one with the oil ring intersection will have a greater chance of blowby...

Just take a look at the piston...pretty simple really.

Rod ratio doesn't have to much to do with anything for most enthusiast. It is part of engineering and can not be ignored.

The 331 for example has an offset wrist pin to improve the rod ratio. They wouldn't design it that way if there was not a reason.

In my opinion it is literally unethical to prescribe to someone the 'longer rod' with a wrist pin that goes up into the oil ring land area of the piston unless they plan to race it. The shorter rod with the same cubes would be a better fit for a true street car.

Ok,for one,most ring manufactors make EXCELLANT oil ring pack "supports" (thin piece of steel ring that goes in between the oil ring pack to bridge the pin gap) that fix just about any problems that you would normaly encounter with a pin/interescting ring piston.

Secondly,rod ratio....STOP WORRYING ABOUT IT! For the street go for the most cubes,only horrably short rods ratio cause problems.The 5.4L mod motors dont have a very good rod ratio and on high milage (100,000+) they wear a little bit on the thrust side,witch oblongs (out of round) the bore just sligthly.Usualy the only problem it causes,it a slight piston knock till things warm up,and maybe a very marginal drop in compression ( havent heard anything about this one,but I would think).

However, I will say for most stroker motors that will be getting rebuilt befor 100K anyways (hell,your worried about rings waring and buring oil,when you'll probably need valve springs befor 50K) dont worry abot rod ratio.Test have shown that a shorter rod ratio can produce slightly more torque,and it also reduces piston dwell time,witch helps with revesion at high rpm (rpm that most of you will never see 8,000+).Of course,it has a larger effect on bigger motors.Longer rod,only benifit is better stability really.

 

[5spd GT]

Ok,for one,most ring manufactors make EXCELLANT oil ring pack "supports" (thin piece of steel ring that goes in between the oil ring pack to bridge the pin gap) that fix just about any problems that you would normaly encounter with a pin/interescting ring piston.

Secondly,rod ratio....STOP WORRYING ABOUT IT! For the street go for the most cubes,only horrably short rods ratio cause problems.The 5.4L mod motors dont have a very good rod ratio and on high milage (100,000+) they wear a little bit on the thrust side,witch oblongs (out of round) the bore just sligthly.Usualy the only problem it causes,it a slight piston knock till things warm up,and maybe a very marginal drop in compression ( havent heard anything about this one,but I would think).

However, I will say for most stroker motors that will be getting rebuilt befor 100K anyways (hell,your worried about rings waring and buring oil,when you'll probably need valve springs befor 50K) dont worry abot rod ratio.Test have shown that a shorter rod ratio can produce slightly more torque,and it also reduces piston dwell time,witch helps with revesion at high rpm (rpm that most of you will never see 8,000+).Of course,it has a larger effect on bigger motors.Longer rod,only benifit is better stability really.

I never said I was worried about rod ratio. Just blank statements are made on how rod ratio effects nothing. Even you just proved that wrong.

There is a point where rod ratio becomes a negative instead of a positive. But not with this aftermarket.

Thank you.

 

[bluevenom867]

I never said I was worried about rod ratio. Just blank statements are made on how rod ratio effects nothing. Even you just proved that wrong.

There is a point where rod ratio becomes a negative instead of a positive. But not with this aftermarket.

Thank you.

Actualy,I was agreeing with you somewhat.....

 

[ammosteve]

PROs are it is a realitivlely cheap stroker to build ie. stock 351 rods and a 302 piston. You only need the 3.85 crank. 10 second power can be had with the right induction.

CONs are all of the folks who have never built one telling you what the problems are. Oh and gas prices.

The 347s with the long rods and ring supports are a non-issue...Chevy folks have been doing it for years without complaints. The oil burning issues stem from poor assemby practices not design. And while some companies are quite reputable don't get caught up on marketing schemes to sell their product.

 

[Grn92LX]

PROs are it is a realitivlely cheap stroker to build ie. stock 351 rods and a 302 piston. You only need the 3.85 crank. 10 second power can be had with the right induction.

CONs are all of the folks who have never built one telling you what the problems are. Oh and gas prices.

The 347s with the long rods and ring supports are a non-issue...Chevy folks have been doing it for years without complaints. The oil burning issues stem from poor assemby practices not design. And while some companies are quite reputable don't get caught up on marketing schemes to sell their product.

Right on

 

[5spd GT]

PROs are it is a realitivlely cheap stroker to build ie. stock 351 rods and a 302 piston. You only need the 3.85 crank. 10 second power can be had with the right induction.

CONs are all of the folks who have never built one telling you what the problems are. Oh and gas prices.

The 347s with the long rods and ring supports are a non-issue...Chevy folks have been doing it for years without complaints. The oil burning issues stem from poor assemby practices not design. And while some companies are quite reputable don't get caught up on marketing schemes to sell their product.

You do not have to build something to know what it does.

You or bluevenom, modular 2v may have built one, but no one else in this thread has

 

[bluevenom867]

You do not have to build something to know what it does.

You or bluevenom, modular 2v may have built one, but no one else in this thread has

Exactly,thats where calculations and estimation comes into play,but that isnt real world,there are variables that you can never predict and conditions that you cant recreate in the real world that look just fine on paper.

 

[Modular2v]

You do not have to build something to know what it does.

You or bluevenom, modular 2v may have built one, but no one else in this thread has

I have not built a 393 but have built a 351 and 408. One of my friends wants me to help him put together the "budget" 393 but the way i see it is, if you are going to take the time to order the stroker crank and .030 over pistons.....why not order higher quality rods? I think i have learned the hardway somewhat at an early age that going cheap on anything just comes back to haunt you later . As for the oil burning issue....... i have a saying that i dont know for sure if it holds 100% true but i thought it was kinda interesting....."Show me a car that has not burned ANY oil in a 3000mile period and i will show you a car that has been towed 3000miles." Im not saying that every single car burns a NOTICABLE amount of oil but you would think it would have to burn some amount!? The structure of the internal combustion engine(way the rings are set) Seem like it would never give a total 100% seal no matter what. Just my thoughts.....not saying they are right but just the way i think

 

[86bluecobra]

One of my friends wants me to help him put together the "budget" 393 but the way i see it is, if you are going to take the time to order the stroker crank and .030 over pistons.....why not order higher quality rods? I think i have learned the hardway somewhat at an early age that going cheap on anything just comes back to haunt you later .

Correct me if I'm wrong but a 393 budget is a stroker crank stock rods and 302 pistons. If I am correct and it is 351w rods that you use then really they can handle a lot of power. I wouldn't be worring 2 much about stock 351w rods. Worry more about convincing him to get arp bolts installed in everything.

 

[bluevenom867]

Correct me if I'm wrong but a 393 budget is a stroker crank stock rods and 302 pistons. If I am correct and it is 351w rods that you use then really they can handle a lot of power. I wouldn't be worring 2 much about stock 351w rods. Worry more about convincing him to get arp bolts installed in everything.

Dont skimp on the machine work,do what you can yourself yes,but if it needs honed,decked,milled,polished,ect. whatever make sure it gets done.Dont just throw a part in assuming it will be fine,check it first.

 

[5spd GT]

Exactly,thats where calculations and estimation comes into play,but that isnt real world,there are variables that you can never predict and conditions that you cant recreate in the real world that look just fine on paper.

My basis is off real world experience, it doesn't have to be built by me to be 'real world experience.'

Like I said alluded to earlier the pistons are different, they had to compensate for the more negative geometry that the longer rod possesses.

I have never said the 347 or 408 will burn oil, like was just stated they all do to some extent. Some quicker than others...

That is just real life.

 

[Modular2v]

Correct me if I'm wrong but a 393 budget is a stroker crank stock rods and 302 pistons. If I am correct and it is 351w rods that you use then really they can handle a lot of power. I wouldn't be worring 2 much about stock 351w rods. Worry more about convincing him to get arp bolts installed in everything.

i know how much power they are capable of.....not a shabby rod at all from the factory. But to be honest if i was going to spend all that money (which i plan on in the future) I would go ahead and order new rods. For peace of mind. I fully agree on the arp bolt issue......... it would be stupid to get cheap with it

 

[5.0 HOtrain]

My 418 wasnt an oil burner, made 581/539 on pump gas, hydor roller, in a full street trim car with a bad driver it went [email protected] the first time out. Also, got a best of 16mph, and a worst of 7 (carbureted). Needless to say, was a fun car, sold now Just me though.
Mike.