383 Project Update

[Kevin - Blown 95 TA]

I was wondering how that was going. How far along are you?

Joe, regarding my stock engine's demise of late fall. I didn't want to hijack the other guy's thread so I started this one.

I have the AFR heads (re)done. I ported and polished them enough to get rid of the CNC marks and polished the chambers & exhaust ports. I opened the roof a little on the 95cc intake runners into 200cc and the chambers from 56cc to 61cc to lower compression. Got the valves & seats cut. AFR Hydra-Rev kit will go in the lifter valley. I ported up the LT4 manifold a little to unshroud the injectors and match the LT4 performance gaskets but didn't weld & port the roofs like they really need. Shimmed up some Comp 318 beehive springs set at 140# closed. Got Comp ProMag 1.6 rockers on ARP 7/16" studs. Going to look at the AFR guideplates, or may use the GMPP ones, not sure yet. Cam is a Comp Extreme 224/236 blower grind. Cloyes Tru-roller timing set.

Engine block is still tied up at the machine shop where they are putting other work in front of mine, but it should be done in a couple weeks even if I have to go there and make fun of them in front of the other customers. I clearanced it for the Lunati Sledgehammer 3.75 stroke crank and Lunati Pro-Mod 6" rods, then chamfered the oil pump & filter passages and did a little deburring. Shop is boring to .030, decking to .010, fitting ProGram caps on 2,3, & 4, then align bore & hone. Pistons are Mahle -26cc, bearings are Clevite H series. Plan on using .045 Cometic MLS head gaskets for a static compression of about 9.0:1. Assy is internally balanced with an ATI neutral flexplate. Also fitted with ARP head studs, oil pan studs, cam and flexplate bolts. Milodon Main studs for a Diamond Stripper windage tray, Moroso (customized) rear baffle & crank scraper, but trying to stay with a stock pan. Stock type oil pump with a white spring & stock 3/4" pickup & Moroso shaft.

Other stuff - Moroso accumulator with electric valve if I can find a place for it (it's huge). Probably AC delete this time around to make room for some stuff like the tranny filter & cooler and make it easier to work on. Will add 60# Siemens high impedance injectors after breakin. Probably rework the Methanol/Water injection to two smaller nozzles instead of the one big one. Rebuilt the opti with a MSD kit.

Other stuff staying same as before - Built A4 with Transgo kit & vacuum modulator, Vigilante 3k stall, ATI deep pan, external filter & B&M cooler. Moser 3.42 12 bolt, Spohn driveshaft, LCA brackets, & tork arm, SLP Shorties & Subframes, Borla exh. with elec. cutout, Techedge Wideband sensor, LT1 Edit tuned PCM. Fuel system is a Racetronix (Walbro) with a T-Rex inline booster pump - stock lines for now but planning on a redo. Autometer boost & fuel gauges. Hotchkiss sway bars, strut tower brace & LCAs. Hal shocks in back with airbags. ZL1 275/315s with BFG drag radials and/or Goodyear Eagle F1 GS-D3s, Z06 brakes & Baer rotors. The blower is still an S-trim and pulleyed up with a 3.12 at the compressor and 6.66 at the crank - we'll see what the boost is with the 383, but I suspect about 8-9psi, maybe less.

Anyway, that's all I can think of.

[fastTa]

You know you want to put on a smaller blower pulley!

[Dan B. 96 T/A]

Nice buildup Kev! Too bad for you I sold the Z. Woulda been a great race! You would definitely have had to pulley up the 383 though... lol.


Shoot me an email sometime!

[Kevin - Blown 95 TA]

You know you want to put on a smaller blower pulley!

I stated the pully size wrong in my post above - it is a 2.95", not a 3.12" so it is 2 sizes smaller than the stock 3.3" and the 6.6" crank pully is larger than the stock 6", but I need the larger T-trim compressor now, rather than spin the crap out of the S-trim.

[Kevin - Blown 95 TA]

Nice buildup Kev! Too bad for you I sold the Z. Woulda been a great race! You would definitely have had to pulley up the 383 though... lol.


Shoot me an email sometime!

Just for that, I won't save you my old parts this time.

[Joe 1320]

. Plan on using .045 Cometic MLS head gaskets for a static compression of about 9.0:1.

Have you thought about O-ringing the block deck? That would make double sure the headgasket seals tight under lots of boost.

[FroSSty]

Have you thought about O-ringing the block deck? That would make double sure the headgasket seals tight under lots of boost.

Thats what I was thinking...But then I remembered reading (in Hot Rod Mag) about a new head gasket by Cometic that has a gas-filled ring that replaces the metallic ring around the gasket. When bolted down the ring actually squishes down a bit. Then if/when, God forbid, the head lifts up off the block, due to high pressure, the heated gas expands the ring and actually seals the cylinders without fail.

The article even tells about Kinetic Racing using an LS-1 supercharged drag-race motor running 30 pounds of boost, generating over 1800 hp with just 385 ci to work with. All this for about 200 bucks... WEll worth the extra moneys imho. You should give em a call for more info...
Cometic Gaskets - 800-752-9850 or 440-354-0777

sorry so long BTW. Sounds like a great setup to me!

[Kevin - Blown 95 TA]

Have you thought about O-ringing the block deck? That would make double sure the headgasket seals tight under lots of boost.

I think it is less necessary with the gaskets that are available today and at my boost levels. The only downside to MLS gaskets, though is possible coolant sealing problems. The Cometics have .001 Viton coating, but you have to have a fine surface finish on the blocks & heads to make it work - it needs to be a RA of 60ish or less for a lot of the MLS gaskets to work (not sure about Cometics. Either way, I'm going to spray them with Coppercoat or something similar to help the water passages seal.

The other thing about head gaskets is that, if you make it impossible for them to blow, something else, like a piston, will take the punishment. Some consider gaskets like fuses. I need to not let it detonate, and that's where the Meth comes in.

[Kevin - Blown 95 TA]

Thats what I was thinking...But then I remembered reading (in Hot Rod Mag) about a new head gasket by Cometic that has a gas-filled ring that replaces the metallic ring around the gasket. When bolted down the ring actually squishes down a bit. Then if/when, God forbid, the head lifts up off the block, due to high pressure, the heated gas expands the ring and actually seals the cylinders without fail.

The article even tells about Kinetic Racing using an LS-1 supercharged drag-race motor running 30 pounds of boost, generating over 1800 hp with just 385 ci to work with. All this for about 200 bucks... WEll worth the extra moneys imho. You should give em a call for more info...
Cometic Gaskets - 800-752-9850 or 440-354-0777

sorry so long BTW. Sounds like a great setup to me!

Thanks for the info and the compliment - will definitely look into it.

[Joe 1320]

The other thing about head gaskets is that, if you make it impossible for them to blow, something else, like a piston, will take the punishment. Some consider gaskets like fuses. I need to not let it detonate, and that's where the Meth comes in.

True....... if the gasket doesn't blow, the pressure must go somewhere. The key is to not let it detonate in the first place. I run those gaskets in my GN albiet with the O-ringed block deck and not the head. No problems with lots of boost providing there is good fuel.

[fastTa]

Cometic makes a killer gasket. The best IMO. O-ringed heads are great for a serious race motor, but for a street/strip blown motor, cometics are perfect. If you DO get detonation or worse pre-ignition, you want the gasket to give and not the head.

Believe it or not, before they started to o-ring cylinder heads, some of the pro teams would tack weld the heads down to the block on nitrous and blown motors.

[Dan B. 96 T/A]

Just for that, I won't save you my old parts this time.

I'm always in the market for more parts! I have a daily driven boxy caprice to build up now!!!