Engine Build

[Evan Adams]

ok guys. A buddy of mines neighbor has a cclb dually with a 6.5td. Its a 95 or 96 has 160k miles and it has a problem with running it will start run till it gets warm then dieds (PMD). Any way for a while now ive had it in the books to build the best 6.5td probly ever. Im getting this engine for 150 bucks if i go pull it out (he lives 2 miles away) and its coming home and will start the tear down, machine shop, and engine stand life. Im going to port and polish both intake and exhaust port. Have the biggest valves possible put in it and get studs for rockers as im not a fan of the 6.5 top end of there valve train (i was born into a family of gasser builders) any way thats the just the heads. For the block im thinking a little boring mabey .010 over and just your everyday machining.(have contemplated the idea of making it a 6 bolt main. (duramax style) with bolts threw the side of the block. As the rotary system goes. Scat crank. H beam rods and 18-1 pistons. Fluidampr balancer and im going to destroke it another 1/4 of an inch. it will get main and head studs. A main girdle (in designing stage now made out of 3/4inch aluminum. Performance oil pump and pan. Building custom plentum to be able to take on 2 turbos. they will be intercooled and custom "headers" with be made to mount the turbos on either side (heath diesel style). I will probly run 2 HX-40II. Im going to run to separate 4 inch exhaust systems exiting on both side in front of the rear tires. Also im having a custom build cam. Going for the biggest cam possible. I will be running a junior moose injection pump. With a raptor lift pump. With a build 4l80e behind this. Did i mention this with be a daily driver and a work truck. with the occasional trip to thhee drag strip. going to run mabey around 30psi of boost max ( 15 each). Any other advice is a blessing. thanks ahead of time

 

[tanman_2006]

Ok, you close but 6 bolt main will not work.

Be prepared for cracks, if the main webs show cracks then you are back to square 1. Basically what I am saying is you will have the wrong block for the job. IF the block isn't cracked the look on kennedy diesel for splayed mains (gasser theory)

You don't want to put larger valves in stock GM 6.5 heads. Get new heads from Penninsular, they will be the new castings that are a lot less prone to cracking (as in none reported on the forums). Then put 81-82 style red block 6.2 valves in, if that isn't available then J-Code 6.2 valves. Harlan Sharp roller rockers will finish it off nicely.

Get gapless rings from total seal. Leave the pistons as is, just coat them and maybe cryo treatment. Rods are fine, the 6.2 link below has a solution to breaking rod bolts at high rpm. Shot peen, cryo and coat the rods if it makes you feel better. Get the rotating assembly balanced GOOD, up to 10K rpm good (use a new delco balancer not a fluid dampner for this). There are no aftermarket rods unless you make some work. There is not any custom pan or performance oil pump needed, at 5K rpm a 6.5L will blow the cdr off with all the oil pumped to the top end and mains ran dry.

W/ 30 psi you will need to fire ring the deck, 25psi is all you will hold before pulling studs or finding the weak spot in a head gasket.

110CC Moose pump and ATT w/ quick spool valve (QSV) will blow a HX40CK2 away anyday. A HOT 6.5L wont spool 2 GM4's until 2500RPM w/ wastegates wired shut, I'm not sure what you plan to achieve by bolting to bigger turbos to a 6.5l. More turbo's isn't better, heaths twins are extremely small garret turbos.

Heath refuses to use the ATT yet he built a turbo kit that use a turbo with all of the same characteristics, just took him 5yrs to catch up and he is still playing catch up in everything but cams and according to a few people the biggest change to the cam is a 2* key. Heath will not release cam specs, turbo specs, or any specs to his race truck.

The set up I just described will put down ~300-325hp to the wheels I bet.

For the trans: triple disk converter, 00 4L80 upgrades, TH400 HD race clutch kit (some tricks to that but pretty well direct fit), MAYBE a transgo kit, and a trans tune.

Exhaust manifolds you should get

Solid 6.2 Build (I'm not a heath fan BTW)

Solid Optimizer Build

All out (ish) P400 Burb

Quick Spool Valve

 

[Evan Adams]

well i was thinking on running 2 smaller holsets or mabey a couple of garretts. I dont reallly have the cash to buy 2 atts at 850 bucks a piece im looking for around 250-300 bucks a piece. i was going to run 18-1 pistons to make it easier on the lower end. Yes i was looking in to the 6.2 heads and will go that route. Im just looking for a bulletproof 6.5. that also will put down some good times on the strip or spank the cummins that pull up beside me and starts black smoking every

 

[tanman_2006]

I would never advise 2 atts unless it's a 600hp dmax or cummins that can spool them

There aren't many options for 18:1 pistons, make sure you bore the block after knowing what pistons are available.
W/ the money you will spend to beef up the gm block and find heads you could have bought a gep/navistar block for 2500 and not have to worry about it ever cracking and still be able to use standard pistons.

Don't get 6.2 heads, get new navistar heads and machine it to fit the valves you want. This was done in the P400 build.

Heath doesn't even recommend twins for dd, sure it will be different but not practical.

Read those threads, do research.

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