55chevr

Need some information on doing a 4.8 L20 engine build for D class land speed project. Using a 1999 Corvette FRC for the hull. Maximum displacement is 5.0 for D Motor. I have a 30k mile L20 4.8 engine with a Howard cam, Edelbrock dual plane, MSD box, Holley 4150 650. Would to bore .060 for 302 displacement. Pistons and rings are what I see as the biggest issue.
Joe

KCS

iTrader: (20)

Total seal makes a 1.2/1.5/3.0mm ring set for a 3.850" bore. That would be 4,987cc's or 304ci. Any of the piston manufacturers could probably set you up with some custom pistons for that bore and ring pack.

55chevr

I know the rings are the toughest part but I would prefer off the shelf pistons if possible.

KCS

iTrader: (20)

I don't think that's possible.

JoeNova

KB and Sealed power make pistons in a 3.819" bore (97.01)mm.

55chevr

I was able to get 3.840 forged pistons (3.78 + .060) with valve reliefs BUT it has a small pin .927 instead of a .945. Manley 6.300 rods have the small pin diameter so I found the match. This makes displacement come out to 302 cu in. Right where I want to be. Now looking for a stronger cam. Considering Crane 1449121.
Joe

pantera_efi

iTrader: (1)

Hi Joe, I USE a 98mm bore OFTEN with Shelf NPR Rings.
I use RaceTec Pistons at 98mm with the cost of a "shelf" item.

Would you like my help ?

Andy Flag won MANY championships (salt) with my help/ECU/tech.

Lance

55chevr

That sounds like it would work at 3.858. I already bought the pistons/rods for 3.840. Any suggestions on a cam? L20 has VVT but no DOD.

Joe

Crf450r420

iTrader: (1)

RaceTec pistons are very nice. I have used many of them before. Actually have 3 large motors with them in the shop now.

gnx7

iTrader: (28)

I use RaceTec/AutoTec pistons all the time. Good quality and price!

For sustained high RPM you may want piston squirters and certainly a dry sump system.

Steve Demirjin at RED in Oceanside, CA can do the piston squirter mod as well as any/all machine work....

I bought the engine out of this truck with a couple fried pistons and then rebuilt it with a 4" stroke crank to gain 80rwtq+ (441ci). You could probably copy a lot from that build! My friend Chris Coffey at Coffey Fab in TN built it from top to bottom. Kurt Urban built the motor.
http://www.lsxmag.com/features/inter...at-bonneville/

55chevr

I've seen this truck run at Maxton. I remember you shook the tires and blocks of salt came out from underneath. That truck makes power.
Joe

55chevr

Any one running on nitrous oxide --- Crane 1449121

Joe

pantera_efi

iTrader: (1)

Hi Joe, YES and I use Crower Cams to Regrind YOUR VVT Camshaft Core.

My ECU-882C will allow you to control the VVT Motor, Advance ONLY for best operation is the WAY.

Limiters Required

Lance

55chevr

I got the heads done by Texas Speed. Really nicely machined.

55chevr

The C5 Land Speed Corvette engine assembly finally underway. 2015 Chevy Express Van L20 4.8 engine with 23,000 miles. Bored to 301 cu.in. by Jack Merkel Performance, Texas Speed 2.5 ported heads on 799 castings, BTR 33350135 cam, forged flat top pistons, Manley H beam 6.300 rods, Johnson 2116 lifters, VVT eliminated.

I am considering either an MSD Air Force 2702 intake manifold. Is there a better performance choice. We are racing NA this year but will be spraying nitrous oxide next year.

Joe

pantera_efi

iTrader: (1)

Hi Joe, YES I manufacture an ITB Eight Stack with 2.5" butterflies.

Many report a 75-100 Hp Increase.

Lance PanteraEFI.com

55chevr

ss.slp.ls1

iTrader: (36)

Cool thread and nice build so far. Just curious, have you calculated your compression? Also, what rpm are you going to shift at? Lastly, I didn't see a mention of exhaust set up, what are you going to use?

55chevr

Anticipate shifting at 7500 rpm. Only had .020" shaved off heads CR should be mid 9-s. We will use ARH long tubes with an X pipe.

Joe

pantera_efi

iTrader: (1)

Hi Joe, I have customers in Tooele, we ALWAYS run more compression pressure in that area. (your at 9.5 ?)

I also ADD Timing, about 1*- 2*, for the Road Cars that race at the Miller Track.

Lance