Well, seeing as how my LT4 spun a rod bearing shortly after completing all of my mods, I have decided to go with the original recommendations of some of the forum's esteemed members.

I decided to go .030 and with a stroker kit. Does anyone have a recommendation on equipment? I found a kit by Eagle, using speed pro pistons for $700. Seemed kind of cheap to me, but I've heard good things about Eagle. Does anyone here have any insight on this kit?

Also, I've come to the conclusion that the LT4 hot cam will not work for me with the new rotating assembly. I would love to get some input on cams from you guys.

Thanks in advance!

 

Broken record starts playing...
- search is your friend. Many of us have posted 383 builds with a wide variety of parts.
- what is your intended usage? Drag race? Road race? Street?
- what is your hp goal?
- what is your tq goal?
- what is your budget?

 

Yes, yes, I get it and have done it. When doing my hotcam mods I got advice from you that I couldn't find the detailed answers to through search. It took me a while to complete (almost 9 months) and then as soon as it was finished, I spun a rod bearing. So, I decided that since I have to tear everything apart, I may as well build the stroker.

That said: Intended usage: Toy. Occassional driving, periodic trips to the 1/8 mile track with the occassional trip to the 1/4. Would like to do 175 at the Texas Mile.

HP Goal: No real goal. Would like it to be in the low to mid 400's at the wheels.

TQ: Same as above.

Budget: Not of much concern. I have a disease where I always seem to search for the best deal, but I'll spend whatever I need to.


So, in the search, I did not find anything pertaining to my original question. The quality of the Eagle Stroker kit with speed pro pistons. I was hoping someone has some insight on it.


Parts so far: Long Tube headers
Cat back system with x pipe
Meizere electric water pump
Ported, polished and matched LT4 heads and intake
Dual roller timing chain
LT4 Hot Cam (need replacement recommendations)
New Optispark distributor

 

There are lots of 383 examples here.

I am not an expert, however you are still gonna send it to the machine shop to be balanced.

Lightwt forged crank, lightwt rods, light pistons = bigus buckus

Look at other builds and see what others have used. I think blackharlyman's build is still in the sticky above. Read it several times.

 

That 700ish 383 kit is a cast crank, SIR rods and Speed Pro hyper pistons.... honestly if your going to reuse the Hot Cam that kit is fine. Your looking at 350-360RWHP with some decent port work.

IF your going to cam it for 400RWHP then I wouldn't use hyper pistons.... it's just a combination of too much compression and too much RPM for me to recommend hyper pistons. The cast crank and SIR rods are still use able if your trying to save a few $$$... you definitely need a budget type forged piston... Probe, SRP, or ICON.

Since we already know you want 400RWHP then the biggest thing I have to ask about is your budget....

What do you have to spend?

Will

 

Don't really have a budget. I usually figure it out after I'm done. Seriously, like to get out as cheap as possible, but will spend whatever amount I need to. Budget is not an issue.

I do not plan on reusing the hot cam, so I'm looking for recommendations on a good cam for a 383 that began life as an LT4. My heads flowed 272 cfm at .500 lift and 297 at .600. With the right cam and rotating assembly, that should make for decent power.

 

You should really think new heads if your looking for 400 rwhp. Been there, done that.. Think for minimum with your intake, 195 afr heads. Call Jim Barth for great price...

 

I used afr 195 heads with the forged eagle rotating assy and got 442rwhp/419rwtq.My cam was a custom ground comp 232/236 @ .050 with .540/.530 lift.I used 1.6 rockers so lift was a little higher.I also had the elec water pump,long tubes,and a 52m TB.

The hot cam will work for you and make decent power but for 400rwhp you may need more cam if your heads can move the air.

 

Thanks man. I went with a lot of your advice on my original mods. After the working on my heads, they flowed very similar numbers to the AFR 195 Street heads. I like the idea of having the LT4 heads on the car, for no other reason than being able to remove the oil cap and seeing "LT4" cast in.

I absolutely DO NOT want to stay with the hot cam, as I feel that would be counterproductive for a 383. I appreciate you listing your cam specs, as that is one of the main pieces of info I am after. I've already made up my mind on a Scat forged crank, now it's just finding the proper pistons, rings and rods.

Correct me if I am wrong, but didn't 96GS#007 get similar power results as you, using the LT4 heads?

 

As cheap as I would recommend for 400RWHP would be cast crank, SIR type I beam rods and budget forged pistons....

Something like this kit. Scat 9000 crank, I beam rods, Probe pistons. $970

http://www.cnc-motorsports.com/rotat...in-seal-1.html

With flat top pistons and 54cc lt4 heads the compression could get too high (almost 12.1) if you deck the block to far and run too thin head gasket.

This kit has a 16cc dish and compression could vary from 10.1 to 10.8. $1010.00

http://www.cnc-motorsports.com/rotat...in-seal-1.html


If you want to go with Eagle -

This Kit (flat top pistons). $1075

http://www.cnc-motorsports.com/rotat...pistons-1.html

Or this Kit (16cc dish pistons) $1105.00

http://www.cnc-motorsports.com/rotat...pistons-1.html

All of them will have to be balanced so that is an additional $150-$250 at the machine shop.

Rough estimates for the rest of machine shop
$200 bore & hone
$150 deck
$150 clean & install cam brgs & freeze plugs
$75 clearance for stroker

As for the cam. My cam grinder is Mike Jones.

http://www.jonescams.com/2006catalog_001.htm

I would recommend something like the EHR71360/72360 ground on 108ICL and 112LSA
276/280@.006 230/234@.050 .576/.576 (w/1.6 rocker)

That cam cost about $395 shipped. There are lots of other options for cams out there.

The heads you have will be fine but your gonna need valve springs and retainers for the new cam.... talk to whoever you buy the cam from about them.
Will

 

Thanks Will!

So you think I'll be fine going with the Scat 9000 instead of the forged crank?

 

At 400ish RWHP I see no problems on a good cast crank with the lighter aftermarket rods and pistons. Espc in a street car that's gonna see more regular driving than WOT.

I always like to use the best parts the customer can afford but but I wouldn't refuse to build a street car engine with a cast crank until we get well past 420-430RWHP and RPM capability gets past 6500 on a regular basis with a 3.75 stroke.... At that point it's 4340 forged crank and rods or take your stuff to another engine builder.

That cam I gave you the spec to is gonna come on about 2500RPM peak HP at 6000RPM and fall off after 6500.... 400-420RWHP in a 383 with near 11.1 compression and good heads. The seat timing is pretty short so I'd put the cap on static compression at 11.25 to 1.... but anywhere between 10.8 and 11.25 would be fine.

Since you have LT4 heads with a 54 cc chamber I went and figured some compression ratios with the various kits.

With the 16cc dish piston, block decked to .010 in the hole and the Impala Gasket (.026) you're looking at 11.1 to 1 SCR and 8.8 DCR.

It just has way to small of a chamber to run flat tops without opening up the combustion chamber.... at 54cc's it's over 11.7SCR.... and that's using .039 Fel Pro head gasket and pretty much un-decked block with the piston at .020 in the hole.....

IF you can get the chambers opened up to 64cc's with the Impala gasket, block decked to .010 in the hole you can get 11.1 to 1 SCR and 8.8 DCR.

Likewise open them up to 59cc's deck the block to .020 in the hole, impala gasket would be 11.34 SCR and 8.96 DCR....

It's a lot easier in the long run to use the 16cc dish piston.
Will