Okay I have all my mods listed in the sig. My plans are to include a 383 stroker, probably some nice JE pistons, a nice forged crank, and 6" eagle h beams. 4 bolt main caps and studs everywhere. Clevite 77 cam/crank bearings. 12# pulley on the S-trim. Lloyd elliot heads and 224/236 crane xe on 116 lsa with all the valvetrain stuff (comp r lifters, proper valve springs for the cam/lift, 1.6rr's, hardened pushrods, etc. etc.). I'll probably get all that top end stuff from combo motorsports in a kit or something. I was also planning to go with a double roller/csi wp but if not then a LT4 extreme duty will be purchased. I am also going with the TechLine thermal intake manifold coating for another 150 as I'm sure that will help a lot with cold air =) I was thinking, I wanted to use the higher lift version of that cam. What top end mods would I have to do to go over .600 lift?

I was thinking that my currect fuel system would suffice as well. I am using 38# lucas injectors along with my alky system that I just finished. I have a Walbro 340 (high pressure) that has not been installed as I don't need it yet. Will that fuel system get my to 500? There's plenty of alky for my car to get drunk on too =)

I want to break into the 500 rwhp range. I'm pretty sure that will do it but I just want to hear it from some people that have already been here. You know, I remember when I used to talk about super fast cars and now it's time for mine to get to that level. I want everything to come out perfect the first time so if you have any tips or anything that you see that is weak in my plans for the car, please elaborate. The only thing that is going to be too expensive is aftermarket head castings, so hence the Lloyd Elliot stock heads. Also, I am going to try to stay emission legal so I want to keep the SLP dual cat headers for now or until I can find somebody that will smog me on one of these new smog machines. Other than that, I want it to be a stout 383 (all forged around 8.7-9.3 compression ratio). Is that low of a compression level attainable with stock heads on a 383?

I know my car talk but when it comes to building an engine this is my first time so any advice would be appreciated. I plan to order all the parts myself and have the block work and assembly done at a local shop with my supervision. So any advice? Will I be able to hit that 500 rwhp mark with shorties and stock heads??? I think I can with a good dyno tune, what do you guys think about my plans? Thanks!

 

I say without a dobt, you will be able to hit your mark. What Im concerned about is your head unit. Now that your going up in cubes, you may want to consider upgrading up to a t-trim. Im not sayng you have to b/c god knows if R.Krause(sp) can make big power out of it I know anyone can. But he was also spraying too. Im not sure what he made with the blower+alky. I guess I'll let him telly ou about that since I know he'll probably chime in here with a responce. BTW, im in the same boat your in too. Im currenty rebuilding a another block as well. Im prety well verse on the termanology but doing it is totally different and I hope to learn alot from m totall rebuild. Good luck man.

 

I would up the injectors to 50's or at least 42's. That 340 pump will go higher than the injectors. As far as the power you should be way above 500rwhp. Depeding on the heads you could come closer to 600rwhp. A cutout on those headers is going to make a real difference.

 

Like what was said above you will have to up the injectors. But I dont know if your S-Trim will be able to supply enough cfm for you to hit 600rw.

 

The injectors are too small. 50's, the largest readily available high-z injectors, will be barely big enough. The pump may be ok, be sure it has plenty of voltage. You do not want to run at all lean with these things, especially on pump gas. 12.5:1 or richer. Run a cold plug.

An S-trim is big enough to make 600rwhp. Mine made 611rwhp with mediocre heads, no IC, water/alcohol injection, small HR cam, through cats. That was a best ever run, great conditions, cool motor. Typical conditions it made in the 590's (M6). Many people are making more with a more radical setup. My approach was a mild setup with nitrous as needed. Still doing it that way at a whole new level (>800rwhp through a TH400 with ~200hp coming from the N2O).

Save your $$$ on the intake coating, if you are on any kind of a tight budget. The same $$$ put into coating your piston crowns will be a much better investment. Next priority for coatings is the combustion chambers and the exhaust valve.

Use the JE "Extreme Duty Inverted Dome" piston. You can get ~9:1 with stock chamber size. Lower would be even better, but that's about as low as you can go. Do not use a thicker head gasket to lower CR (ruins quench).

Rich Krause

 

Thanks for enlightening me fellas. I was under the impression that my injectors coupled with the alcohol would give it enough fuel but I guess I was mistaken. That's one thing I'm going to have to start looking into replacing. So I'm going to need some MSD50's??? Or would 42's be enough? What size were you using when you hit 600 with you S-Trim Rich?

Also, I asked about the cam and the top end. I want to use a cam similar to your cam, higher lift, 116lsa, 114 intake centerline etc. Can you break it down for me exactly what you need in the top end to use the lobes with over .600 lift??? Can I also get the part number for that cam.

How helpful would coating the piston crown, combustion chambers, and/or exhaust valves be to my car? I was thinking intake manifold to prevent the engine from heat soaking to make it more consistent (although it has become very consistent since I put the alcohol kit on it). I'm guessing the idea is to lower combustion chamber temp and piston surface temp to prolong life of the piston under harsh use correct?

I think that for now I am going to try to reach my goal with the S-Trim head unit and then upgrade later, possible even go to a turbo setup and swap the cam out and make some real nice power =) Hopefully it will be able to move enough air.

Thanks for responding!

 

I don't have a pn handy, but just make sure that whoever orders the cam specifies it's for an LT1 and the correct year (to get the correct length dowel and diameter center hole). You want the XE HR lobes #3192/3196 on a 116LSA with a 114 intake center line. The Comp Cams springs to use are either #977 or #978 or a comaprable srping from someone else. You will also need a high quality pushrod, good rockers, etc.

The coated piston crowns will add hp and contribute to piston longevity. Coating the intake isn't a bad idea, just of less importance.

You will definitely need 50# injectors. That's what I was using, but I also had a Superfueler to allow for boost indexed fuel tuning.

Rich Krause

 

Just for reference I have 50lb injectors in my 385 s-trim with 5lbs boost and the injectors are at 88% duty cycle @ 5700 rpm. The 50lb'ers don't like high duty cycles or high fuel pressure. I plan on getting 72# with converter box even at 5lbs boost. I am also switching to 12 lb pulley which I will probably see 10lbs boost. You will definately need bigger than 50lb'ers running 12lbs boost and you can never go to big so you might as well go with at least 72's

 

In case my post wasn't clear: I agree, more than 50lb/h injectors will be needed. I was at ~70% duty cycle on the 50lb "main" injectors and the 3x90lb injectors on the SF were at ~80%. I also would suggest the Acceleronics box and some big 'uns. I am using 90lb injectors now, they are at ~60% duty cycle with 17lbs of boost. And that is with 50psi of base fuel pressure.

Rich Krause

 

Out of curiousity, what kinda HP are you putting to the ground?

Thx,
Claude

 

Old setup ~600rwp with just the blower, 733 with a 125hp nitrous shot. That was through a T56. Currently, 876rwhp with a 200hp nitrous shot and 610rwhp without nitrous through a TH400 with a 4,200 stall converter.

Rich Krause

 

72's and a converter box is almost another 1000 bucks! Jeeze... Any way I could get that PN Rich, thanks! Maybe I'll just leave the 6# pulley on there for a little while...

I wanted to know how exactly I need to achieve the lowest possible compression ratio with a 383 and stock ported heads. I'd like to use an off the shelf piston, not custom. What should I go with? Are some brands better than others, why? What type/brand of rings should I get, and bearings as well. I need to start making a complete list of everything I will need. For my motor I am thinking that 4 bolt mains will be strong enough to hold. Am I better off trying to find an LT4 block or converting mine to 4 bolt mains?

 

Have you looked into the 57lb high z injectors from Racetronix??

 

Check out www.caspeed.com where Allen did exactly what you are attempting with a 383, S-trim, no aftercooler and with MSD 50#/hr injectors. He has also some LT1 files that you can download to help with your tuning. I believe Allen hit 525rwhp and is almost maxing out the 50#/hr injectors - at 50psi and 85%.

You may be able to squeeze by with 50#/hr injectors but if you can I would definitely go with LJ's box and 72#/hr so you don't have to do the injectors twice. This is with no FMU; with the FMU my Accel 36#/hr was able to handle 476rwhp easily at 30psi fuel pressure.

If you don't have to worry about smog, I would highly recommend getting some long tubes. I sold my shorties for some Hooker LT coated by Jethot when I did my rebuild as well. Everyone said that is a must and I totally agree.

Is your head flowing well. You can also think about bigger valves. Anything to help evacuate the exhaust is a plus.

cheers

 

I run 42# injectors with the Racetronix twin intank pump setup. My injector DC maxes at 96% at peak HP (around 5K rpm's) I made 542Hp and 633 Tq at the wheels. Keep in mind though the twin pumps put out about 70 psi of fuel press when both running (stock lines and FPR)

Bill