C5-R 427

[LMN8R]

Who makes the C5R 427 CID engine for the C5R? Is it chevrolet? Lingenfelter or some other tuner? Someone else that I haven't heard of?

Just wondering.

-Greg

[Edmond]

i do believe that the c5r is a bored out ls1 block.

someone correct me if i'm wrong...

[J-Rod]

The C5R block is a special casting. The cost of the block is around $6995 for a bare block. You can buy the engine as a bare block from GM, and have the shop of choice build the engine. The C5 racing program is handled for Chevrolet through Katech. They build 427s for customers. A C5R street engine is over $20K from them.

The only thing a C5R block gains you over a re-sleeved Ls block is added strength in the mains, etc... This block will gain you no HP over a production block. But it will ive under higher HP loads such as a high boost twin turbo, etc...

[Rob]

Originally posted by LMN8R
Who makes the C5R 427 CID engine for the C5R? Is it chevrolet? Lingenfelter or some other tuner? Someone else that I haven't heard of?

Just wondering.

-Greg

Katech Inc.
24324 Sorrentino Ct.
Clinton Twp., MI 48035

Phone: (586)791-4120
Fax: (586)791-0802

[LMN8R]

Okay, cool. Thanks alot. The only thing I'm confused about is on the official Corvette page. This states that the C5 and the C5R engines are both LS blocks. Does Chevy/GM supply the block to these folks to beef it up, or is it a completely different cast that the company makes itself?

Originally posted by LMN8R
Okay, cool. Thanks alot. The only thing I'm confused about is on the official Corvette page. This states that the C5 and the C5R engines are both LS blocks. Does Chevy/GM supply the block to these folks to beef it up, or is it a completely different cast that the company makes itself?

It is a different casting but with similar architecture as the LS1/6 block. This is why it is called a "LS" block; just like the cast iron blocks in the new chevy trucks are "LS" blocks (same architecture).

The main differences between the two are the "stock" bore sizes and the bottom end. The C5R block has a much beefier bottom end. The extra strength comes at a hefty price though; the C5R bare block costs over $6,000, vs. about $4,000 for a complete, assembled LS1 motor.

[TCSF]

The C5-R block has a 4.125" inch bore and is also made of a stronger aluminum alloy.