8.1 Aluminum cylinder heads and other new products

[tbyrne]

 

This is a BIG POWER mod for your 8.1 motor! You'll be able to pick up 40+ horsepower and also take 100 lbs off the front of your truck with these aluminum cylinder heads.

 

Cylinder head specifications

 

Applications: GM 8.1 liter 8100 vortec (L18) engines

Mercury Marine 496MAG or 496HO

GM vortec Marine HP1, HP2, HP3 versions

Volvo Penta Marine GS8.1& GSX8.1 engines

Crusader 8.1 &8.1HO Captains’ choice engines

Indmar 8.1 & 8.1HO Malibu,Mastercraft engs.

Materials: Lightweight a356T56 Alcoa alloy aluminum

Heat treated and hard anodized for marine use

Method: Smooth cast

 

Machining: all required machining on 5 axis CNC centers

Valve seats: super alloy hardened high strength steel

Valve guides: manganese silicon bronze

Valve seals: super viton in steel "top hat" bodies

Valves: stainless steel EV8 with 11/32" stems, high flow necked stems with black nitride strength treatment after fabrication.

 

Valve sizes: Intake valve 2.20" x 12degree w/11/32" stems

Exhaust valve 1.725" x 20 degree w/11/32" stems

(Optional Inconel 1.725 exhaust valve x 20 degree avail.)

Rocker arm studs: Hardened steel with 8MM x 1.0 threaded top with

thrust nut base for mounting stock rocker arms with stock nuts, or

(optional) Raylar Stainless roller rocker arms with "all the way down"

adjusting nuts.

 

Intake Ports: 315cc. High velocity-High flow smooth ports

Exhaust Ports: 135cc.High velocity-High flow smooth ports

Complete Assembly: Includes:

Valves-intake & exhaust

Springs, retainers and locks

Valve stem seals, valve guides

Rocker studs and guide plates

Complete 5-angle valve job with

Back cut valves with special margins and radiuses.

 

Price - $2799.99 - free UPS ground shipping is being offered for all heads that are pre-ordered. We expect to start shipping these sometime in April!

 

A totally new intake manifold is in the late stages of development. It will allow much better airflow into this engine at all operating RPMs and allow it to develop more power and efficiency when combined with the new cylinder heads. This manifold will not create any added space considerations nor will it require any modification to stock or aftermarket marine configuration sensors, senders, injectors, fuel rails, brackets or hardware. Horsepower gains for the top end upgrades (heads and intake) will be in the 60-65+ range. More exact numbers will be available soon!

 

Other 8.1 products that you'll be seeing in the springs are - more aggressive cam grinds along with 1.8 ratio rockers.

 

Tom

[02 2500avalanche]

Ya Tom just when I though I was almost done modding, NOPE, o boy the wallet is going to be hurting come this summer. I have been waiting for aluminum heads for the 8.1 for a while. Now I still gotta through that cam in along with the rockers, just been too lazy

 

Alex

[LikeaRock14]

Tbyrne!!!!!

We're looking to supercharge our truck this spring possibly, wondrin how much a Whipple kit from you would cost. The one I found was on proficientpermormance.com I think, for like around mid$3k. It's for an 00 Chevy, 7.4 ltr 3500. Could you gimme a price?

[o4yukonxl]

These are much more interesting than the cast iron ones. I was hoping a set of aluminum ones would be coming out soon. This is a serious horsepower maker for the 8.1. Fortunately, my dyno guy can handle 500 RWHP or I'd have to go back to SOTP.

 

Can I assume that the Crane Rollers will bolt onto these heads?

[tbyrne]

02 2500avalanche. So have I. The stock heads are HEAVY! I weighed one in at about 90lbs. The two aluminum heads should weigh less than a single stock version.

 

LikeaRock14: We sell the 7.4 kit for $3899.99.

 

o4yukonxl: The Crane rockers will bolt up fine.

 

I've been thinking about adding a few more horsepower mods to my HD to spin the 37" tires that will be going on in the spring. That truck will probably get a set of these heads along with the intake manifold, 1.8 rockers and maybe a more aggressive cam. All this will be good for about 100+hp.

 

Tom

[juiced01s10]

think you could stuff a 8.1 into a S-10, hehehe if so I have a test vehical for ya.

[HanSolo0260]

think you could stuff a 8.1 into a S-10, hehehe if so I have a test vehical for ya.

I'll go one better, lol. I'm tempted to squeeze an 8.1 in my 3rd gen Firebird, instead of the popular LS1 swap. I found a few low milage ones for under $500, but without harness and computer.

[juiced01s10]

some day I will get the funds to do a 6.0 with a built bottom end, radix blower, cam, and some of the juice in my s-10. not to mention a quiet exaust to top off the sleeper look