Haulin' 8.1

Hello boat guys, I'm asking this because I'm building up a hot truck that has the GM Vortec 8100. This is basically the automotive version of the 496HO. You guys have collectively done a lot more modifications to this engine than most truck guys I've been able to find online. I have a set of HP3 heads and a Whipple supercharger that will be installed at the same time as the cam. The pistons and rocker ratios would be stock for now. Before you think about detonation and cracked pistons know that I've already sucessfully converted the truck over to E85 fuel and have used it exclusively since May, this fuel is very stable and a intercooler. I believe it will be well within detonation limits but only one way to find out. The cam I want to use is a Crane catalog grind (#268721) with these specs.

Dur. @ 0.050" INT 222 EXT 230
Advertised Dur. INT 284 EXT 292
Lift INT .576 EXT .598
Timing Open/Close at 0.050" tappet lift
INT 4 / 38
EXT 52 / (2)
Deg. lobe sep. 112

If anyone can tell me if this would or woudn't, may or may not and why I would appreciate it. I can't really gamble on taking the family truck down to the cam only to find it won't work and having to order another high dollar camshaft then wait for it.

By the way I do own two boats but not nearly as nice as most of you guys. Ones an older "Sportster" Penta 5.0 and a '90 VIP with a 2.3 Ford. I have a old T-bird turbo coupe parts car that I think about using to turbo the boat but that's as rich as I get.

Thanks for any help you can give,
Vernon

Raylar

PLEASE DON'T iINSTALL THAT CAM IN YOUR STOCK ENGINE!
The stock 8100 /496 pistons have very small valve reliefs and the maximum lift they can take is .510" without having the Intake valve smack the piston!
For a supercharger grind cam for that stock block I would recommend something close to your duration numbers but your LSA number needs to be in the 115-117 range for the
fuel injection system.
We have several of our 496/8100 cams available as we do a lot of engines and parts for 8100's in trucks and such.
Visit our website www.raylarengine.com or click on our link here and you can contact us toll free @ (866) 496-8181 and we'll help you with a cam if you like.

Best Regards,

Ray @ Raylar

Haulin' 8.1

Hey thanks Ray, your level of expert knowledge was just what I hoped to find here. I do know your products for the 8.1 are top shelf. I didn't want to bother you personally because I've not yet been a customer of yours and couldn't promise you that I would. I understand how you don't like giving out your knowledge all the time for people who don't plan on being paying customers. I found this site by searching your company name and read through most of your posts. Info on this engine is short, even the cam companys can't tell me what they sell will or won't fit. I'm in no hurry so I WILL give you a call after the holidays and discuss what exactly I will need to complete this prodject and place an order. At least then I can relax knowing the parts have been tested and proven by Raylar and I'll not have any major surprises. I had already planned on calling you up for hardware and head gaskets etc.

Would custom pistons in compression ratios around 12.5 trough 13.3 to 1 be a problem for you to supply? I'm really digging the Ethanol.

One last thing, if your looking for a good place to drum up some truck parts business, the GM Gassers Forum at www.DieselPlace.com is full of 8.1 enthusiasts begging for more power. Look it over and consider becoming a supporting vendor. It would be great to have your level of support over there and many of those guys have a lot more money to play with than I do.

Most grateful,
Vernon

MrLipps

I know this question is late, but I have to know.
Hope you guys can help

Do the 496 mag engines use different pistons then the 496 truck engines?

Quick2500

There's late, then there's 8 year old thread late......

Ryan00TJ

iTrader: (8)

Same pistons.

Keith Atlanta

Yep, same ones.

Diamond Pistons makes a nice forged replacement and of course, so does Raylar.