My 8# twin intercooled LT1 broke a ring land after 3000miles. I was seeing 8# of boost, AFR of 11.3:1 throught the rev range, and NO knock! Oh well.

I want to rebuild to 550 to 600rwhp and need to know what will get me there. The car is a daily driver seeing 15,000miles/year. It needs to be able to run at the track and still live a long life. I'm not planning on stroking it, only doing a 355. I've got 42# injectors, stock intank, and ATI in-line. I was planning on running a 12rib 12# D1SC. It's a street car, so I would want good low end torque and probably only rev it to 6200rpm.

My questions are:

1. How much do I have to have my stock heads worked to get to 550 to 600rwhp on 12# of boost with a cam? Is a mild clean up port/polish enough, or do I need larger valves, and more serious porting?

2. What cam would be a good choice for this? I know Rich was happy with his Comp Cams XE lobes #3190/#3192 on a 114lsa 214/224 ground straight up. Would this be a good choice for me?

3. What kind of rotating assembly would be good? I don't want to pay for overkill, but I do need it to be able to take some hard driving/track days and last a few years. We only have 91 octane gas here, so I was thinking around 8.5:1 CR.

I need to start ordering parts quickly so I can actually get some use out of this car, as it is parked during the winter. Any help would be appreciated.

Thanks,
Brent M.

 

You will need some decent heads to come close to 600rwhp on 12#'s.

If you are planning on that much power, and beating on the car, might as well only have to do one rebuild.

I'd go with all forged rotating assembly. Might as well go with a stroker if you have to buy a new crank anyways. 4 bolt main too.


Look at the LT1/LT4 Street Stroker Plus: http://www.cmotorsports.com/lt1shortblocks.htm


You will need to upgrade your fuel system.

 

1. You can't make that much hp with stock heads. You will need porting.

2. The cam you should use is CC lobes #3190/3192 on a 114LSA and a 110 intake center line.

3. 8.5:1 would be nice. You will most likely need a custom piston to get this with LT1 heads though. I really like JE "Extreme Duty Inverted Dome" for SC applications. Heavy, but hella strong. JE #100F8 for a 5.7" rod/3.48" stroke combo is an off the shelf piston with a -22cc dish and would give ~9:1 with 58cc heads.They could probably make a custom with a bigger dish and the right compression height, you should call. Take a look at http://www.jepistons.com/pdf/2002-je4-13.pdf to get some ideas.

My last 383 combo with an S-trim made 597rwhp with no intercooler, the above cam, water injection, and out of the box AFR heads, which flow less than ported LT1 castings. The CR was ~8.5:1. It had 16-18" of vacuum and peak hp at ~5,700rpm.

Keep in mind that if you want to make that much hp you will need a fuel system to keep up with it as well as a good exhaust system.

Good luck!

Rich Krause

 

I too like a 355 for a every day driver, its just me but i think a 355 is stronger more reliable. Crank will cost the same money though. Callies,eagle or cola crank (forged)will all be able to handle the power. I use JE pistons and eagle I beam rods. I too went with 8.5:1 to ensure no detonation problems. I have no problem with low end either, infact i need traction big time. Im happy with the 224/234 @50 501 516. It has a nice idle too. Its all about how much you wanna blow on the heads. I went with a mild+ job and i guess im at 500rwhp.

Dont you have the dual intank pumps?

 

I don't have the dual in-tanks. I've been trying to buy them, but haven't been able to, so that is why I posted the question on them. Seems Racetronix is backed up with orders for them right now. Hopefully I will have the duals before my car is running again.

I've just said the heck with it and decided to order a fully assembled 383 stroker from either Nu-Teck or Combination Motorsports.

I've looked at the cost $7350 for a good 383 stroker and by the time I get my heads done, replace lifters/pushrods/RR's/cam, full forged and balanced rotating assembly, upgrade the timing chain, gaskets, ARP bolts, etc, I will have spent as much rebuilding mine to a 355 as a fully assembled 383 would cost. 600rwhp will be the goal.

What pistons did you use to get down to 8.5:1? I wanted to use the JE Extreme duty blower pistons, but like Rich said, they only come in a -22cc dish. I haven't called to see if they would do a custom dish.

Brent M.

 

I am using the -22cc piston, but have 76cc chambers. It's a "custom" piston. JE pn 131631 has a -31cc dish and the correct compression height for a 5.7" rod/3.75 inch stroke. That's gives 9:1 with a 58cc chamber and should work well. They will make a custom set though, just call or fill out their piston order form and fax it.

Rich Krause

 

LOL well why not if 7k is a budget engine, but than again im only 21 and dont make that much money. My motor was like 3.5 k with heads, if you do a search on my name i posted a post with all the prices parts and labor it took to build my motor. I dont see how so many people spend 5-8k for a stroker. Do they give a warrantee(<---spelling?

 

94SLUG, I tried going to your website, but it wasn't available. I wanted to see what you were running for 3.5k. That is doing really, really good for an engine. I didn't say it was a budget engine, but a "good 383 stroker".

A _good_ set of heads cost anywhere from $1500 to $2500. Add that on to a fully forged short block and a person is easily at 7k. With a 600rwhp target (therefore good heads) and reliability (therefore forged internals) it is not that hard to spend 7k. All the little things add up very quickly.

Brent M.

 

Im sorry for the website, its one of the free ones. Try to reload and you should be able to get in. 1500-2000 for heads is not a fair price for a daily driver stock casting. Theres no reason to go to a after market casting for 600hp. My P&P was 400 bucks and i dont care what anyone says you can get a good job done for reasonable price. Yet i did spend a lot of other money on RRs,valvs,springs,........ In my case the machinest was building a lt4 for his daughter so he was happy to play around. The work was very nice and i would tell anyone to go to STREET & STRIP (miami, fl).

My web-site is a little wack (out of date)but nice PICs .

If i can get this damn scanner working ill put the invoice on the web site .


A fully forged sb is only 1500-2000 depending on your hooks, and even somtimes way cheaper if time is on your side!

Bill