ThirdGenLT1

Hey, I'm working on a LT1 out of a 95 9C1 caprice. I was originally going to rip it apart, port the heads, get a mild cam and be done. Well plans have changed and I'm going to build a 383. I have a couple questions about rod lengths. What are the advantages/disadvantages to shorter/longer rods? When I do searches for 383's I see people using rods from 5.7" to 6.0". If it helps this engine will be N/A, no nitrus/supercharger or anything.

Second question, the iron heads... now outside the weight factor, is it worth trying to port these and use them on my project, or should I just pick up a set a used aluminum LT1 heads and port them?

Crank, I plan on going with a forged unit, scat or eagle, any opinoins appreciated.

Pistons, (Froged) brand suggestions would be great, I know the exact piston will be determined once I figure out what length rods I will be using.

I am looking to build a strong/fast engine, but still a daily driver, which is why I am focusing on forged components.

One last question, block is 2 bolt main, is it a good idea to look into 4, or will I be fine?

Thanks for any help, I'll return the favor whenever I can!!!
Matt

ThirdGenLT1

Anyone, My main area of confusion is the rod length.....

Prorac1

The longer the rod, the beter the rod/stroke ratio. Also the longer the rod the less side load there is on the cylinder wall. Not a real big deal on a mild motor. But in the planing of my 383 build up (natural aspiration like yours) im going with the 6 inch rod (usually the same price no mater the length, so may as well get em long. and the pistons are about the same as well. the reason for going with a shorter rod (or mid length 5.85) is for piston heigth. on a nitrous motor you want a nice thick piston top to take the heat and abuse. I hope this helps Prorac1

speedmiser

Depends on what kind of 383 you plan on building and your budget . You dont necessarilly need to go all out forged this and billet that to have a strong running dependable street motor. What's you hp goals and how high do you plan to spinning the motor?

My 2 bolt 383 has been together for over 5 years now with stock rods (resized w/ polished beams and arp bolts), scat cast steel crank, and heavy shots of dope. I'm running forged pistons, since the goal was to spray it all along, but you could get away with hypercraptics.

Of course, if you're looking to build something well over 400rwph and continually spin it over 6500, then yea, look into some stronger parts.

ThirdGenLT1

My plans as far as HP, I would like over 400 at the wheels, @ 500 at the flywheel. As far as budget, I have no set budget. I plan on building the engine over the next 18 months, so I am doing it once and doing it right. I am gathering all the internals for the shortblock first because I am going to Wyotech in April and I plan on assembling the shortblock there. I don't want to waste money, but I'm not going to cut any corners. If you feel that for these power expectations I don't need all forged components, let me know. Like I said I don't need to waste money, But I do want a strong reliable engine.

Thanks, Matt

gb95zconv

I its gonna be NA only go with the 6". With a forgeb bottom end it would be a real shame not to spray though....in which case I would go 5.85" like I have.

ThirdGenLT1

Ok, after doing some more research, I'm finding that I probably don't need a forged crank, I am settling with the scat 9000.

For rods I plan to go with the Eagle H-beam 6" rods. P/N from cmotorsports.com is "EG-LTH600"

Pistons, well I'm set on SRP's Flat top. P/N from their website is "138093", is this a good choice? They have so many pistons, I think this is the one for my application.
Specs for piston.. 383 ci, 3.750 stroke, 6" rods, 1.125 comp height.

I've done tons of searches, but keep finding mixed answers. Anyone see any problems I may have with this setup?

Thanks, Matt

Dave88LX

If I remember correctly, when I did the math, a SRP flat top piston with 5cc valve reliefs will give you ~12.78:1 CR. SRP's got some 16cc inverse dome pistons that will give you ~11.2:1 with .006" milled off your heads.

Shoot an email to Brian Adams, scatstroker@hotmail.com and see what kind of price he can get you on an LT1 383 stroker rotating assembly. Scat 9000 Crank, Scat 4340 Forged I-beams, SRP Inverse dome 16cc pistons, p/n 138103.

Register at smokemup.com and use their calculators. Do a search on me for info on my stroker build-up to grab some more info.

385LT1

here is some motivation for your project......

383 cid LT1 91 RS 6spd

http://www.abrinoperformanceengineer...y/IM001219.jpg


http://www.abrinoperformanceengineer...y/IM001218.jpg

S.J.S.

I went with Eagle 4340 crank and Eagle H-beam 5.7 rods with SRP pistons. You are building exactly what I just finished with the same results in mind. Daily driver with about 400RWHP.

Just to let you know....whatever you plan on spending as far as budget wise. Make it 2k over that. Thats how much mine ran over. Had to upgrade injectors....PCM.....TB....tranny with stall was a big one. Its the lil things that kill you though. Dollar here..dollar there....motor mounts. Hell it just snowballs. Let me know if you need any info. I attempted to put it in this week with a major drawback so I had to stop to get more parts.

good luck