zr11990broken

Ok guys I have spent untold money rebuilding this engine and this question came to ma as I was reading the string on radiators. With this engine which will be Im told 500 rwhp (yes I like to say that) from your experience do you think I need a new rad I will be using evans coolant with a 180 ,wheres the degree symbol on a keyboard. Have any of you had any probs with yours after rebuilding them to 368.

USAZR1

How are you planning to use Evans Coolant with a stock LT5 water pump?
Just my opinion but I would forget that idea.
Buy a Ron Davis radiator,add water,20% regular coolant,and a bottle or two of Redline WaterWetter. That should handle your cooling problems fine.

Rkreigh

the evans is pretty expensive and designed for a low pressure system.

not sure how that will work out for you as clint mentioned. I have a 368, 180 stat, ron davis rad, and right now a manual fan switch (until I get the old LPE chip fan strategy reprogrammed) and the car runs @ 200 or less at crooze which is about right (generally between 190 and 195).

even with the stock rad (if clean and free of debris) the car ran OK but would creep up in temp in traffic (240 is too hot for me!!) with the AC on. the stock radiator really isn't adequate IMHO for the HP level you are running and the plastic end tanks are prone to cracking from heat cycles as they get old.

don't really need anything exotic IMHO even with the high 12-1 compression of some of the 368s. fan and airflow are the more of a problem in stop and go, once croozin, temps drop to mid 190s or less.

you might also consider replacing the stock small fans with the large "nascar" style electric fan, flows quite a bit more. I understand the factory vipers have a pretty high flow fan and SPAL makes some nice units too.

definitely check out the ron davis, a very nice unit, only light mods to the cushions and cooling stack cover to install.

keep us posted on that 368!!! :reddevil :cool: :D

A26B

Would you mind sharing with us what all has been done to your 368? The 500 rwhp is about 50 hp higher than a typical 368. That much of a gain from different cams? Naturally I'm interested in knowing and seeing dyno cards because I'm planning a 368 build this fall after the summer driving season.

Jerry

Jeffvette

That's the issue, typical usually is no cams which is where you can pick up some big power along with a big price tag. ZR1broken is using one of the last sets of 470 lift cams. Jim Pritchard has them in his car as well. I don't think he has dyno'd his yet.


If you have to pass emissions, don't count on using anything but the stock valvetrain

Rkreigh

even the 368 with the stock cams retimed proved marginal for me passing emissions. I tried with both the stock ZR1 cal and the LPE cal, failed twice, and finally passed by getting the car VERY hot and just squeaked by with a little alchohol in the tank for insurance. even doing all that, the car was right on the ragged edge of passing.

I know one of my cats had a cracked core (which I'm sure didn't help, and rattled like crazy)

but indeed I had a tough time and just BARELY passed with my 93 LPE 368 on the rear wheel dyno test. also the 368 has always seemed just a tad bit sluggish below 2500 in comparison to the stock cam timing. after that, look out!! it revs and pulls hard to 7500 and is just plain scarey how flat the torque/HP curve it.

I'd like to hear more about your build up for a 500 RWHP 368, sounds like it would have to be pretty radical to do that IMHO without nitrous or other power adder. I don't think just cams will get you there.

fast lane build a 373 (368 + .030 overbore on liners) that made 675 HP, but he had some pretty radical mods and I believe very high compression and wasn't too streetable. anyone know more about that particular build???

after seeing his 431 make a few passes, I was a believer!! cya.

zr11990broken

as far as I know the stock water pump is fine with evans coolant at least they told me it was and i have the low pressure caps.

as far as the engine I got the last set of Billy Kirchoffers 470 lift cams, 60 hp over stock. Since I have the same setup as Jim Prichard and that is what he is running,if Im wrong correct me and Ill look like a fool again, that is what Im bragging.

as far as emisions testing Im a used car dealer I have my ways. Besides there is is no need for it if you took every car off the road it would not make any diff in air quality, global warming is just a tool used by the one worlders to get people to conserve their recources. If you can get oround it do it


[Modified by zr11990broken, 12:16 AM 4/30/2003]

zr11990broken

I want to know more about the 373 you were talking about I was told I couldnt do that . What did he do that I could not have. tell me tell me tell me

DDSLT5

He's running something around 15:1 compression ratio - only race fuel will work in this engine - thus not too streetable. :seeya

xsmph

Last time I heard, I think Jim P. with the big Jeal 470 lift intake/450 lift exhaust cams was at around 470's rwhp, but TQ was at around 380's...
if this is not his car is another 368 with huge cams that is running around.

Kurt's 415 has these same cams, siamesed runners and big valves.(567 rwhp) if you go by hp/cid, i guess a 368 could be at 500 rwhp, but i dont think so. high 470's is possible though. Somehow the bigger cubes motor take more advantage of the bigger cams/valves combos. If you could rev it higher it could be possible. But 7400 rpms is where most set the limit at, and 500 rwhp out of a 368 with 12:1 is very difficult in my humble opinion.

FastLane 373 ( same set up as a 368, but .030" overbore on the std. 4" pistons) did do 675 on engine dyno, about 560 rwhp, but it had all done to it, and 17:1 CR. His current 431 is 16:1 CR.

Keep us posted on the 368, is Bill K. doing the work?


[Modified by xsmph, 5:51 PM 4/30/2003]

zr11990broken

Bill has done the work its now time to shove it back in an haul azz

xsmph

Post dyno/track numbers as soon as they become available. Thanks!

FU

The man go's right to the matt !!