8.1L Whipple 2.9L Supercharger
#11
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You can always order a procharger kit for a 496MAG and adapt it to your motor. That'll give you 3.5-5lbs of boost.
https://www.procharger.com/marine-su...cruiser/efimpi
https://www.procharger.com/marine-su...cruiser/efimpi
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Its been a long time since our last update, but we picked up a 2003 GMC Yukon 2500 off craigslist with an 8.1L (4x4, 3.73, 4L80E) that had blown its pistons up. After tearing the old 8.1L out, we tossed in one of our new 8.8L / 540cid crate engines with stock iron heads and a 202 cam.
For those wondering, the 202 cam in a 540cid displacement is perfect for stock heads as the cam falls off right about the same time the heads do (4200rpm). In terms of driveability, this combo might as well be a dead stock offering from General Motors. Expect about 440hp / 540ft-lbs.
We decided to make the GMC a test mule for the the 2.9L blower kit which is finally back from the casting company. After driving it around town, all I can say is blower whine is the ultimate mechanical temptation to stand on the throttle.
Here are some shots of the completed kit - we should have dyno numbers in the next week or two for the 540 budget build.
For those wondering, the 202 cam in a 540cid displacement is perfect for stock heads as the cam falls off right about the same time the heads do (4200rpm). In terms of driveability, this combo might as well be a dead stock offering from General Motors. Expect about 440hp / 540ft-lbs.
We decided to make the GMC a test mule for the the 2.9L blower kit which is finally back from the casting company. After driving it around town, all I can say is blower whine is the ultimate mechanical temptation to stand on the throttle.
Here are some shots of the completed kit - we should have dyno numbers in the next week or two for the 540 budget build.
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Yep, you can't go over .530 lift or the valves start kissing the pistons. If you do have aftermarket pistons, you still have to cut down the iron head's valve seats as they have the same limit.
Our 201 Heavy Towing / 202 Towing / 203 Street Strip / 211-S (supercharger) / 212-T (turbocharger) are all safe to run with stock pistons.
Here's the description for a 202 in a stock 496 / 8.1L: High torque camshaft. Stock-like idle. Best for daily towing emissions compliant Truck / RV use under 8000lbs. Safe for stock pistons. Powerband: Idle - 4700rpm
#17
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Thanks!
Yep, you can't go over .530 lift or the valves start kissing the pistons. If you do have aftermarket pistons, you still have to cut down the iron head's valve seats as they have the same limit.
Our 201 Heavy Towing / 202 Towing / 203 Street Strip / 211-S (supercharger) / 212-T (turbocharger) are all safe to run with stock pistons.
Here's the description for a 202 in a stock 496 / 8.1L: High torque camshaft. Stock-like idle. Best for daily towing emissions compliant Truck / RV use under 8000lbs. Safe for stock pistons. Powerband: Idle - 4700rpm
Yep, you can't go over .530 lift or the valves start kissing the pistons. If you do have aftermarket pistons, you still have to cut down the iron head's valve seats as they have the same limit.
Our 201 Heavy Towing / 202 Towing / 203 Street Strip / 211-S (supercharger) / 212-T (turbocharger) are all safe to run with stock pistons.
Here's the description for a 202 in a stock 496 / 8.1L: High torque camshaft. Stock-like idle. Best for daily towing emissions compliant Truck / RV use under 8000lbs. Safe for stock pistons. Powerband: Idle - 4700rpm
What about LSA? I was considering a 114LSA. Stock 8.1L Long block with a Modified intake and a 90MM TB
Thoughts?
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114 is about the minimum you'll want to run in terms of LSA. Our towing cams (201/202) are on a 116 to maximize output with the long runner intake and produce the broadest possible torque curve.
Last edited by Raylar Engineering; 03-13-2016 at 12:09 AM.
#20
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What do you recommend for springs? I was looking on your site and your valvetrain package says to go to comp for springs.
I see an outer spring and a beehive spring?
Is the Beehive for a stock replacement with factory locks and retainers and the outer requires different locks and retainers?
I see an outer spring and a beehive spring?
Is the Beehive for a stock replacement with factory locks and retainers and the outer requires different locks and retainers?