McDude

Guys, I'm in the process of getting prices to have a shop rebuild my 95 Z28 LT1 motor and making it a 383 stroker with a forged crank, rods, and pistons. It currently has a 9psi procharger, 52mm throttle body, headers, crane ingition, and 30lb injectors. The drivetrain is stock with an auto trans, and a 2.73 gear. This car hasn't been started in over 10 years. It's not going to be a daily driver, just for nice nights, weekends, and perhaps a couple trips to track. The plan is to have compression of 9.5 to 1. Should I have the stock heads rebuilt or should I invest in some after market heads? I'm probably going to go with a mild cam From what I'm reading here, the stock converter is gonna be a drag. What size converter would be a nice upgrade for me. Also I think the 2.73 has got to go, I'm thinking maybe a 3.43. I don't want to pour huge amounts of money into this but I also want to do the work once and be done with it. I guess I want to get the most bang for my buck. Any suggestions would be appreciated.

nader454

For what you have planned for the car, if it were mine, i would get a 3600rpm stall, and 3.73's.

ItsRyan

Ok if you build a 383 stroker with a ProCharger then plan on replacing your whole driveline starting with the transmission. I have a 383 Stroker with about 10k invested including machine work. To bad I can't put it to the road until I get my new tranny. My tranny will cost me about 2500 to 2700 with new stall convertor. Then Im sure the driveshaft is next then the rearend. etc. etc.


GoodLuck on your build!

97WS6SCharged

The stock heads should be sufficient for what you're planning. Just send them to Lloyd or AI or a good porter and have them do some magic.

As for the converter question I would call one (or more) of the companies who make converters and see what they recommend.

NightTrain66

YANK SS 3600 stall and 3.42 gears will work great. Transmission will need a rebuild and shift kit isntalled for sure.

Make sure that you use good valve springs, rockers and pushrods.

A small cam is what you want to build boost and trap cylinder pressure. The CC 305 or CC 503 cams are descent choices for a catalog cam, just use a dbl spring with 150 bs of seat pressure.

Stock heads are OK, just get good springs, valve job, milling, etc.

If you get aftermarket heads, the TFS 23 degree haeds are a good choice (just adjust piston choice for the 62 cc chamber). You will need to shim the springs for more spring pressure or swap springs with these heads.

If you already have pistons designed for the small chambers, the 21 degree TFS heads are a good choice. These come with springs set up for what you are gonna run.

adam85

^^^ Wow! Haven't seen you post on the forums in a long time Lloyd! Glad to see your still sharing some knowledge.

Kevin Blown 95 TA

30# injectors are too small, and you're going to have to do something with your fuel pump to get more fuel up there, if you haven't already.

NightTrain66

yea, not much time for thr forums lately, jst been too busy.

I try to get every now and then and help out if i have time.

Lloyd

McDude

Thanks for the imput guys. Regarding the heads, is just having the heads rebuilt sufficient? From what I have heard, porting the heads is not very important on a s/c motor. Y/N?

Regarding the gear, I see Lloyd Elliot says that the 3.42 is great, would a 3.73be better. From what I remember the auto trannys have overdrive so when cruising the motor wouldn't be reving to high anyway? Also having a 2.73 gear that means that it is has a 2 series carrier, meaning that it would have to be switched to a 3 series to accomodate a new gear. I have seen a discussion talking about richmond and perhaps others make a thicker 3 series gear that will work with a 2 series carrier. Anyone familiar with this? If I have to changed the rear end later, I want to put as little $ as I have to now to get me by.

Regarding the 30lb injectors, what is going to happen or not happen if I stay with them. Bigger is not alway better.

Also, regarding the forged assebly, the machine shop I've been talking with was planning on using an Eagle kit, are these pretty good as a whole? I see talk on these forums where everyone seems use different cranks, rods, and pistons on the same assembly. Is it that big of a deal? Isn't that fact that they are forged enough.

Lastly, does anyone have an estimate at to what kind of HP I should be putting out.

Kevin Blown 95 TA

First of all, you are building a bigger engine and you are not going to be running aorund in boost all the time, so go ahead and port the heads and get some good springs on there keeping in mind the intake valve will have to have a little extra help to open when you are in boost.

3.42 works well with a blown car and you will have a bad enough problem with traction anyway. Yes you can us the thicker gear from Richmond - I built a 10 bolt that way and it worked fine.

You better put some thought into your fuel system, do some homework and learn how to figure this stuff out, or take the advice from someone who already has been down the road you're headed down. If you buy 30's now, you'll be buying 42s or 60s later. Built 355 NA engines use 30#.

Eagle cranks can be good or they might not be. Depends if you get a good one or not. That's how it is with the Chinese parts. Their rods are OK, but it is a lot easier to make a rod than a crankshaft.

You aren't going to be putting out any measurable horsepower. As a human, you are just too small and weak compared to a brewery horse. Maybe hook yourself up to some weights and see how much you can pull in a minute then measure the distance you pulled it and you should be able to calculate how much horsepower you are putting out. It will be some number way less than 1.

McDude

Kevin, LOL on the HP response.

Regardeing not being under boost all the time,
isn't it being put out in direct relation to the rpm's? In essense always under boost just not very much at low rpm's.

As for th'e Richmond gear, I'm glad to hear you did the same and it works fine. Is it noisey?

As for the fuel system, I am going to install a 255 in lieu of the stock pump, and there is already a boost pump that is part of the procharger system. The 30lb injectors are what are already on the present motor. Can I get by on these or will these severly restrict performance? When the rebuild is done I will have it tuned of course, but if I find it necessary to put in bigger injectors I would have to have further tuning adjustments made, right. I really don't want to be tinkering with changes all the time.

Kevin Blown 95 TA

You wil make boost near 3000 rpm (depending on rear end gear), pulleys, and whenever your bypass valve closes. So most of your cruising around isn't under boost - but that is a good thing, and it's designed that way.

Some Richmond gears have a little noise - Mine was near perfect - I think I had a little noise about 40 mph, but that was about it. Richmond gears may not be as quiet as GM, but they are a bit tougher. Whoever does your install will, to a great extent, be a factor on how quiet the gearset is. I always stone my ring gears and make sure they lay totally flat on the differential - it's the small things that make a difference - and which most people skip. Also use the Ratech spacer and not the crush sleeve. Takes a bit more patience for setup, but it eliminates one more weak spot in the 'made of glass' 10 bolt rear end.
the fuel pump you mentioned will work with the booster pump up to a point, then the booster pump will become a restriction, I'm guessing some point past 500 WHP, but it's just a guess and that means if you use the stock pulleys for your supercharger, it might work for you. If you get to the point where you mash the pedal and it bogs really bad, you might be experiencing loss of fuel pressure, an instant lean condition, and have to get rid of the inline pump and maybe add a second in-tank pump. With your injectors you will have to log some banzai runs and see what your pulsewidths are doing - you may be used up by 5000 rpms or something - you'll have to see. the other thing is get an electric fuel gauge in the car, they cost $200 but that will tell you what is going on with your fuel pressure. You might want a wideband, too and a boost gauge. Don't expect some generic mail order tune to give you the best results. You need to log it and see what's going on and make adjustments. And get the hardware and instrumentation you need.

96capricemgr

Look into the Ratech Smartsleeve. I used one and they are easist to assemble and are supposed to be stronger than shims.
I have a 8.5" which is already a LOT stronger than your axle so I can't comment directly on if it helped strength.

I do know I have setup a number of 8.5" with standard crush sleeves and a 7.5" with a shim kit and one 8.5" with the smartsleeve and will try and use the smartsleeve from now on. The 7.5" and 8.5" are the exact same architecture, some of the shims are even interchangeable.

97WS6SCharged

Kind of difficult to answer completely. The blower will help to make up for any short comings in the heads but a good set of heads are still important on an FI engine. The LT1 heads are pretty good from factory but the ports are a little small for a healthy 383.

True but too small is generally worse than too big. I'd look on tech for a set of Motron 60's personally. They're good for an easy 600 rwhp before they start becoming an issue.

Eagle's forged kits are usually pretty good. I have one in my 383.

Yes, boost with a centrifugal blower is directly related to engine RPM but you will not see much if any before 3000-3500 rpm because the blower isn't spinning fast enough to move more air than the engine can use.

Ditch the booster pump and install 2 255s in the tank. Just don't go crazy like I did.