Welcome to the Corvette Forums at the Corvette Action Center!

2 or 4 bolt main's?

twiget

Well-known member
Joined
Nov 2, 2000
Messages
1,302
Location
The Land of Enchantment
Corvette
In the market
I read somewhere that the '90-'92 LT5's had 2 bolt main caps and that one of the upgrades done for the '93-'95 LT5's was to make them 4 bolt main's.

Is this true or what?

Jason
 
A

ArtZR1991

Guest
Both have a forged steel crankshaft, and the main caps are heat fitted into a "ladder" frame lower end. When the hoesepower was increased to 405, the rpm was a bit higher (for the rating), so for liability reasons, the cap part of the ladder was changed to 4 bolts.

To my knowledge, there has never been a problem with either. Keep in mind that the endurance records set (and still held) by the ZR1 were set with a 375 hp, 2 bolt engine.

Regards,
 

rkreigh

Well-known member
Joined
Dec 27, 2000
Messages
216
Location
Alexandria VA
because of the ladder design of the bottom end the 4 bolt engines probably only add about 5% strength from what I read. Probably more of a marketing than an engineering thing as all the gearhead are after "4bolt" engines.

has anyone ever converted a 2 bolt engine to a 4 bolt config???

could the 4 bolt bearing ladder be added to a 2 bolt block and the engine line honed??? can the 2 bolt ladder be drilled or modified???

I've heard of using studs instead of bolts, anyone ever hear of this being done???

tia for any tips.
 
A

ArtZR1991

Guest
Straight on the LT5, and the "ladder" frame, which it has is another descriptipn of a "girdle", isn't it (I mean automotive, not women's apparel, you wise guys!)


PS, I assume everyone knows, but the prototype w12 Volkswagon broke the ZR1 records a couple weeks ago. My hat's off to them; after all, records are meant to be broken. We ZR1 folks can still feel good in having held the record for so long, and for being the only production engine to ever hold it, since WWII. The W8 was a 600 HP one off prototype, as was the car, not intended for production at anywhere near that level. The LT5, though used in an old test mule Corvette ZR1, was an off the production line engine, sent to the track instead of going into a production car. And that's the way it was when it set the records!
 

JT ZR-Won

Well-known member
Joined
Dec 6, 2000
Messages
1,291
Location
Bradenton, FL
Corvette
'90 ZR-1 #3010
ArtZR1991 said:
PS, I assume everyone knows, but the prototype w12 Volkswagon broke the ZR1 records a couple weeks ago. My hat's off to them; after all, records are meant to be broken. We ZR1 folks can still feel good in having held the record for so long, and for being the only production engine to ever hold it, since WWII. The W8 was a 600 HP one off prototype, as was the car, not intended for production at anywhere near that level. The LT5, though used in an old test mule Corvette ZR1, was an off the production line engine, sent to the track instead of going into a production car. And that's the way it was when it set the records!

Well said Art :)

Jay
 

Corvette Forums

Not a member of the Corvette Action Center?  Join now!  It's free!

Help support the Corvette Action Center!

Supporting Vendors

Dealers:

MacMulkin Chevrolet - The Second Largest Corvette Dealer in the Country!

Parts/Accessories:

Vetteskins

Advertise with the Corvette Action Center!

Double Your Chances!

Partners

Top Bottom