4.7l forged turbo build underway

[TheZaZ]

All of this going in a 97 Cherokee Country that im building for the street and strip. No 4 wheelin or rock crawling here.

Parts list:

95 HO block
KB IC944 .060 forged pistons w/sealed power moly rings
RPM 4340 Forged I Beam long rods with ARP 8740 Cap Bolts
New Scat stroker crank thats also been nitrided
505 performance Nitrided Race cam and lifters. 226/234 .570 lift 114lsa
Teflon coated bearings for cam, rods, and crank
New Heavy Duty Casting head fully ported and polished w/ Ls1 size valves (2.00/1.55). Exhaust valves were upgraded to Isky Racing valves since ill be turboing it.
Dual valves springs good to .600 lift, titanium retainers, viton seals
ARP Head Bolts
Heavy Duty Single Roller timing set
505 performance Roller Rockers
Chromeoly pushrods
3 layer metal head gasket
Girdle
505 performance 70mm billet throttle body
99+ intake manifold bored to 70mm and port matched to head
Stainless steel header
Balanced rotating assembly

Im sure i forgot some stuff but thats most of it. Once its broke in then I'll begin the build the turbo setup for it. Going with a front mount intercooler and shooting for 15-20lbs of boost. Just thought i would share my build with you guys.

[TheZaZ]

Few pics

[TheZaZ]

Crank in

[Muad'Dib]

Whats your calculated SCR and DCR? Why not a dual roller timing set??

[SilverXJ]

x2 on the timing chain. There have been a few failures on the single chain. AFAIK there is no "heavy duty" single roller chain. Just a single row. Hesco sells one as well. Same thing with a "heavy duty" iron head casting.

What are the specs on the cam? I'd be interested in the DCR as I don't know how the KB944's compression ratio will handle boost. I'd also like to see how the cast camshaft handles the heavy spring.

[TurboTom]

Whos engine manangment system are you going to use?

[TheZaZ]

The head is a new casting. Not a 7120 or 0331. I had the machine shop shave .020 off the block. Head gasket is .042 thick. Cam is being ground as we speak and then nitrided. Should make it alot stronger. I cant remember the scr and dcr i came up with. Thought it was around 9.5:1 and 8.17:1....have to run the numbers again.

Specs on cam were 226/234 duration (not advertised, at .050")
.570 lift, 114 lsa. I dont have have the rest of the specs at the moment. Being custom ground for my setup. Ill have them in a few weeks when i get it.

Most likely i will end up running E85 , but ill see how it runs on low boost (5lbs or so)

[SilverXJ]

Most likely i will end up running E85 , but ill see how it runs on low boost (5lbs or so)

Ahhh... That should make the compression + boost work better. Planning on dynoing it?

[shawnxj]

505 claims the single roller they use is stronger then a double roller, supposedly it's from a 502 chevy just not sure i believe them

[TheZaZ]

Yea im definetly going to dyno it before and after the turbo. I havent decided on engine management yet. It will be one of the standalone setups available...just havent decided.

Yea the timing set is from 505.

[Muad'Dib]

I personally wounldnt trust it.

[Busey]

My machinist recommended the early style single roller over the double roller, for strength and accurate timing. He showed me the wear patterns on used timing sets and the single roller actually had more contact area. Golen engines use a single roller and Hesco sells the single roller drilled for cam adj. bushings. He said the only drawback is the single roller doesn't run as quiet.

[gradon]

After my stock single soft-ductile-iron cam sprocket failed(by 35K), I'd never run a non-billet gear again(why I chose the Rollmaster/JP over the Mopar dual). Don't know what the HP singles look like, so post a pic.

[Busey]

around 1992 and earlier engines had a single roller Cloyes #C3085
1992 and later engines have a silent link chain Cloyes #C3041
I am told the the #C3085 is much stronger but run louder
I have both , I will try to take a picture tonight
Grandon, do you know which type you had fail ?

[montelibre]

20 psi, even with E85 and that C.R., is not to much boost?
What octane is the E85?