No - I thought you said it will be a 383....the number you are looking for as the final on a piston is compression height which will change with different stroke and rod.

#131636 will put you in the same place compression-wise.

 

Don't be a wussy... just join the club and build a 383.

-B

 

Building a 383 would be almost no difference cost and effort wise. I want this thing to be as strong as possible and be able to reliably handle more boost than a 383 would let me.

I don't have the restriction of "blown383" forcing me to go that route.

Any update on your motor? Who's doing it?

 

Thanks. I'll try that part number.

Another question. I submitted a different thread, but haven't gotten any responses. I was wondering what the disadvantages would be if I did NOT use hellfire rings. It seems to be the consensus that they are not the best for high-mileage motors like mine because of the cylinder wall abuse. So, if for the sake of longevity I decide not to use the hellfire rings, what will I be giving up???

 

Profiling refers to altering the contuor of the counterweights to decrease the drag resulting from moving them through the oil in the crankcase. This can add a few hp, especially at high rpm (7,500+) where the gain can be considerable. I don't know a lot about it. But interestingly, the shape of the trailing edge is as, or more, important thean the leading edge of the counterweight. No one knows the "best" shape, but a long, smoothly tapering profile for the trailing edge works best. Kind of like a LSR car tail.

Drillling the pins can decrease rotating weight without penalizing strength.

Rich

 

Hey Rich, what are your thoughts on the hellfire rings?

Should I risk the cylinder wall wear since almost all the miles on the car will be freeway miles, or should I just go with a normal gapless ring?

Thanks for everyone's help so far!

 

I just found that that piston has a -22CC dish. Has anyone seen a -31CC version?

 

WRT the rings, being realistic these things blow up before they wear out. Or, you will decide to change something and have the motor apart anyway.

Rich

 

Crap, I have to sound dumb and ask what "WRT" stands for?

Are you saying the gapless toprings will be fine up to those boost levels?

 

WRT= with regards to

IMO, either the hellfires or any good plasma moly ring will work fine for you. Rich is also saying that something else in the motor will likely fail at these power levels before you will wear out your rings or cylinder wall, or you'll have the motor apart changing something else before they wear out anyway.

 

OK, thanks.

Well, the question still is what will I be sacrificing if I don't use hellfire rings?

After this build, I don't plan on opening up this engine unless it blows up, and I'm doing everything I can to make sure it is as reliable as possible.

Also, it looks like JE doesn't make an off-the-shelf piston for me. Do I have to order a custom one through them directly?

 

Didnt you start another thread about that?


IMO, probably very little to be sacrificed. If anything, I guess the rings might not seal as good under extreme boost pressures. But running 15-20 psi, your motor wont be a high mileage motor, as much as you want it to be. And BTW, everyone says they're just going to drive around under low boost and rarely turn it up... but guess what happens... they dont And eventually something breaks.... I tend to agree with Rich.... something else will fail long before a hellfire ring... Maybe you should just try those. You should just go ahead and give up on that whole high mileage thing now.... and go buy a daily driver as well.

 

I did, but no one wants to respond to that post for some reason.

I live in California and the car will be driven with the heavy traffic side of the commute. So basically, I have no choice but to not be under boost.

If normal gapless rings give a little on the sealing, would that cause any damage to the motor, or do I just a little bit of that boost benefit?

I'm getting a motorcycle to help cut down the miles though.

 

I am not a big fan of gapless rings. This is not so much based on any bad experience but my inherent conservatism. Yes, they give better leakdown numbers, but I have never seen convincing evidence of more hp compared to properly installed and gapped "gap" rings. Since I am basically conservative and know what works, I tend to stay with it.

Rich

 

I think I'm leaning away from moly rings since they tend flake during detonation. Although I'm hoping for little of that, it makes me a little worried.

I think I'll risk the cylinder wall wear instead.