mdacton

yeah it does. too much trouble for nothing.

383 is plenty of cubic inch to make good h.p.

user 647483

Good luck with the build man, I'm interested to see how it works out for you.
Sometimes it's fun to be different.

Formula408

Well guys thanks for the opinions. To answer a few questions I am using a 6 inch rod,I don't think you can do less because of piston to counterwieght issues. This does make for a very short skirt piston with a lot of sideload.(not for daily driver). I honestly don't know my compression height I would have to do some asking on that one.
As far as a cam I went with a .900 base circle which is common for a solid roller cam anyway, and I used stroker clearanced rods. I don't have the cam yet but I can tell you when the rods are at there highest point they do not go above the bearing journal.
As far as reliabilty I can't say yet. But what I can say is that I have seen guys break through on 383s and a lot of guys dont. I barely broke through on my 4inch and in all honesty didn't need to. I would say an experienced builder with someone willing to spend the money for the good rods mentioned in earlier post on the thread could do it with good chances of success. For a rookie probably not a good idea. But i'm not sure that a 383 for a rookie is a good idea either.
Yes sometimes it is good to be a little different, You can build plenty of HP with a turbo ecotech but that's not my cup o tea. I have honestly never been a stroker fan. But I figured if I was gonna do it, go all out! I plan on a all NA motor and knowing the torque difference from 350 to 383 a 408 should be a torque monster.

2000GTP

Interesting buildup, definitely something different and unique. Keep us posted on the final result.

Masnart39

The most common is a 6" rod with a 1.000" compression height. As mentioned, the skirts are pretty short.

blkchevyz

i feel sorry for the guy who has to tune that thing.

marshall93z

Why?

blkchevyz

because its me.

Formula408

It has to get in the car and run without an oil pan full of water first! The shortblock is sitting in garage collecting dust now waiting for the cam to get here.
I think I figured out the devcon problem and have it repaired for anyone that still cares to hear. I believe the splayed cap bolts caused an issue unfortunatly I had to pour a little more after machine work but it will be ok I hope. Another lesson learned... Do the Devcon FIRST!!! before ANY machine work. There are some knowledgeable guys on here and I thank them for there replies.
I don't think its the 408 ci that scares him in the tuning process, he forgot to mention his reasoning. But thats a long way off and I'm still holding my breath.

CANTONRACER

I ruined a perfectly good block years ago trying to build a "bigger than normal" small block.

But, it turned out the machine shop I had do the work actually had an LT4 block, Milodon billet mains, everything done for $750 so really was better off. Customer never picked it up.....

AdioSS

it has been suggested to me that if you are wanting to go with a 4" (or even a 3.875") stroke, then buy your crank and rods with small rod journals to help with camshaft clearance issues.

rskrause

Well, that has many pros and cons. To sum it up, a max effort motor would be where you think about that kind of thing. It should be considered only if a top quality crank is used or if the motor is going to see frequent teadowns/rebuilds. The crank is going to be significantly weaker with small journals. OTOH there is less friction and clearance is improved, as you suggest. Bearing wear will also be more rapid with smaller journals.

Edit: clearance will only improve in this scenario IF a custom rod is also used. This will be very spendy. Most small journal rods have the same big end, just a smaller hole bored in it.

Rich

AdioSS

Do you folks think a 5.85" rod with 1.125" compression height piston would work at all? A while back I picked up a set of 4.030" pistons for cheap because they were very close to what I thought I needed for a engine I was working on. Wiseco tech Brian Nutter said they were originally ordered for a NASCAR SuperTruck team. That means they were designed for a 3.500" stroke since their displacement limit was 358cid.

I have no doubt that they'd work with a 3.75" crank and 6" rods. But naturally I want to push the limit. My heads will be able to support a larger engine at the PCM limit, so why not?

One bonus would be an increase in the compression ratio of about .8:1 with the longer stroke. Another is that I'd be able to run a longer duration camshaft to make even more horsepower without losing torque.

The skirt length is 1.335" (total piston height 2.460" minus known compression height 1.125" since measuring from pin centerline is difficult.)

Cylinder length on an LT1 block seems to be about 5 and half inches. That means that the skirt will start to hang out with any stroke longer than 3" With a 4" stroke the skirt will hang nearly an inch out of the bore at BDC. I am not sure if that will work or not.

AdioSS

Rich, I've seen 800-900hp motors using small journal rod journals. Of course they have absolutely top of the line crankshafts and have frequent teardowns like you said.

Agreed with the custom rod. I do believe there are some off the shelf small journal rods with smaller outside diameters.

rskrause

5.85 + 1.125 = 6.975" If the deck is 9.000 this leaves this piston 25 thou in the hole with a 4" stroke. Maybe I missed an earlier post, but how does that increase your CR?