one the bench

[dwilfong]

Well I am taking a break from RC boating to do a few projects.

I am rebuilding the LS2 eng in my Trailblazer SS.

Here are a few pics of the rebuild.

 

[Andy Brown]

Nice David!

Why after market pistons? I little more performance due to a litghter piston at the cost of a long lasting rebuild? What cam?

 

[dwilfong]

The forged pistons are made by JE and are .005 over. Thy are 110g lighter than the stock cast pistons GO figure.

The guy that did the machine work (David Croom) dose about 50 LS eng a year for a air boat builder and Corvette guys.

This is the only piston he uses as thy are tight fitting and the wrist pin hole is off set in the piston to help control piston rocking.

Thy hold up better than the stock cast piston as far as wear and don't rattle when at idle. Those Corvette guys don't want to hear any rattle in the eng....LOL

The thin sleeves in the LS2 block can not be board out much or replaced as the liners are cast in to the block. Cast pistons start at .020 over. Can't take more than .010 out of the sleeve.

I am using the stock roller cam but have changed the rocker arms to a higher ratio from the stock 1.7 to 1.9 . this will increase the lift to .587 from stock .525 wile still mantling the stock valve open and close timing but will add timed area with out a aggressive lobe lift profile.

The only down fall is the SS rockers are heavy..........150g compared to the stock 100g so heaver duel springs are needed. 140lbs seat and 375lbs open pressure.

New stock nodular cast crank and using the stock powder forged crack cap rods with ARP bolts.

The eng had a 6500RPM red line stock it will spin 7000+ with this setup. will see where it makes the power when I put it on the chase dyno for the tuning.

Will bump the cam 4deg advanced to start.

Should be 400+HP at the rear wheels on the Dyno. Stock thy run about 300HP at the rear wheels and 394 net at the crank.

Will see if the 4 weeks of head ports , chamber , intake and throttle body porting paid off........LOL

I will post the Dyno # and 1/4 mile times when I am done.

Need a BAD truck to tow the Vector when it is done...................

 

[Charles Perdue]

I re-did mine last year, 2001 Chevy PU with the 5.3. Tried to help the towing power and mileage. I did the same port gasket matching, cleanup and unshrouded the tops of the intake ports where the fuel injectors sprayed directly against the cylinder head/ intake mounting surface. Installed slightly reduced head diameter 6.0 intake valves with a fancy valve job. New Speed-Pro pistons, Total Seal rings and a Comp Cams torque camshaft set at 4 degrees advance.

I also had 2 1/2 inch dual exhaust ran all the way out with RV, 3 chamber turbo mufflers, made and installed a 4 inch diameter stainless steel elbow for the intake air inlet tube between the mass airflow sensor and the throttle body to do away with the restricting plastic contraption that came on the truck stock. Removed the stock fan clutch and installed a large thermostat controlled electric fan and shroud from a Ford Crown Vic Police car.

It tows much better and the gas mileage went from 19.8 MPG to 22.6 MPG on the highway. Not a world changing difference but it made it better to drive and much, much cheaper than a new truck.

Charles

 

[dwilfong]

getting close now.

Should be in the truck this weekend.

 

[Tom Foley]

You can drive it up to the Suwannee BBQ Nov 13 weekend and feed your boating frenzy as well as feast on mass quantities of great food with giant bonfire !

 

[Chris Wood]

When I am not doing boat stuff I am messin with this

.

 

[dwilfong]

Very nice ride there Chris.

Would be afraid to drive it down my dirt road. Would take a week to clean it up..............

 

[Chris Wood]

Thanks man

Ya it had never seen rain lol

 

[SayMikey]

Guess its just the pic ,dont care for the margin on those intake valves. Should be a rocket,might as well put a supercharger on while your there

 

[dwilfong]

Dang mine had 186000 mils on it before the it got a rod knock.

Thy are finally paving the road in a few weeks. So may be I can keep it clean after all this work.

The dang new Fiat I got the wife floats down the road when it rains hard...........LOL

Lost a hub cap already....she don't know how that happened.............

 

[dwilfong]

I thought the same when I took it apart. But thy guy that did the valve job said thy are like that on the LS2 eng.

Was going to put some larger valves in the heads to get a better margin. But he said don't do it thy don't like it.

He builds one LS eng almost every week for the air boat guys. Thy run the crap out of them wide open all day.

The stock valves are very light and expensive for this eng. Used the old ones over thy where fine.