Engine rebuild feedback

[ogrice]

I'm a new subscriber to the forum and I am looking for some feedback comments about the rebuild that I had completed on my truck.

I have a 93 c3500 std cab dually, 6.5td. I started the rebuild with a crate 6.5 long block. Internally, i've had the entire rotating/reciprocating assembly from harmonic balancer to flywheel balanced to 5000 rpm.
I lowered the compression from 21.3:1 to approx 18.7:1 by shaving .030 from the top of the piston crowns. The compression ratio calculation assumes a .020 compressed head gasket thickness. Did this because I didn't want to spend the cash for the Peninsular 18:1 pistons.
Tossed the timing chain and went with the dual idler phaser timing gears.
Tossed the stock cooling pieces and went with the dual thermostat housing and 130gpm waterpump.
Stayed with the GM-3 turbo. Had it rebuilt to oem specs. Tossed the oem canister wastegate and bought the turbo master adjustable wastegate. Decided to not go with the stock upper and lower turbo manifold. Instead went to a 6.2/6.5 NA intake manifold with the Banks Power upper intake. Had to go back to the turbo shop so they could fabricate a turbo outlet pipe that would work. The NA intake manifold has visually larger runners and ports than the turbo manifold.
I bought the BD 4" exh kit w/ a 3" mandrel bent
x-over. I had the stock exh manifolds and x-over pipe ceramic coated inside and out. The exh impeller side of the turbo I also had ceramic coated in and out.
Tossed the oem intake box and opted for a K&N open element intake.
At the time of the rebuild, my crank pulley had given up and was giving me the rattle of death noise. I opted to underdrive the accessories by installing a Ford Racing serpentine belt main pulley. It threads into the same 4 bolt holes and the belt height sits about 1/8" taller than the stock pulley. The over all underdrive from stock is big. About 25-30%. Found a new belt length that works good.
New injectors, new DB2 inj. pump. Tossed the stock electric priming pump and replaced it with a Holley Blue electric fuel pump.
Thats pretty much it.

Other mods are dual electric cooling fans.
1-piece flywheel with stage II kevlar clutch disc and pressure plate. Preluber aux oiling system. Stainless steel braided oil cooler lines. Tossed the oem bench seat and installed the reclining driver/pass replacement seats from Jegs.

Right now its been one year and 12k miles since completion. My truck runs smooth like a gasser. Totally different from before the engine rebuild. More mileage, acceleration, torque. Less noticeable vibration, runs cleaner, runs a lot cooler, just plain better.

[More Power]

Good job!

You've done your homework well. I agree with everything you've done, except I'd recommend an engine driven fan if you plan to tow heavy/large trailers. The highest rated dual electrics I've seen pull 5200-cfm. A 21" Duramax 9-blade can pull more than 10K at 3000 rpm.

I've heard from a couple other performance 6.5 owners recently who followed more or less the same buildup we did a few years ago. Both are very well satisfied with the power, smoothness and driveability. One of them has an 11K# wrecker, which has been used to tow some large vehicles. The owner told me there's not been a need for more power yet. smile.gif

MP

[gmenor]

Don't mind me asking what was the total damage cost.

[chickenhunterbob]

Good job indeed,

And, I (myself personally, not being a real gear head) cannot imagine how you could have done all of this without being on TDP, but you must be a pretty darn good mechanic!

I tip my hat to you, sound like a fine vehicle you have made.

Welcome to TDP and keep us posted on your truck, it sounds to me like you have a very fun truck to drive!

And on edit, PS, (since I see your sig) I am also a datsun Z fan, I owned a 1980 280ZX for 11 years, from new, and have been sort of casually looking for the identical car now for a bit. Talk about FUN!

Bob

[ogrice]

Attn gmenor,

After the tally on all my reciepts, the total cost for the engine alone was around $2800. If you're wondering how I managed to keep it that low, well i'll tell you how.
I got the engine from Frito lay. A friend of mine knows a guy who works for Frito lay. The delivery trucks run 6.5 NA engines and at regular intervals, they change out all of the engines for a grouping of trucks. They do this whether it is needed or not. I'm sure that all of the fleet guys know this thing happens. All of these engines go to whoever wants them and usually only in bulk quantities. I asked my friend for a favor since I was ready for a rebuild. He got me one particular long block that had less than 2000 miles on it according to the vehicle logs. It cost me two cases of beer and 500 bucks for the long block which was on a crate and wrapped in plastic when i picked it up.
Took the engine to the machine shop to get it checked out and worked on, they said that the engine had virtually no wear on it. No carbon, all the bearings are in perfect shape like they were right out of the box, cylinder walls had the crosshatchings with residual oil still in them.
Sweet deal.
All the other labor was done by my brother and I. Everything since the truck was down to include transmission, steering, brakes, 6 new tires, all the other parts including ones that I didn't list down, etc. has cost a total of about $7800.

[patrick m.]

two things im not sure about. One is using the GM-3 turbo.
It has been discussed many times the only GM turbo worth anything is the GM-8 (performance wise).

The other issue is under driving the accessories. If something isnt done to speed the alt back up, your tach will not be accurate.

Not to mention needing all of the cooling availible.

Other wise, i wish i were finishing mine up as you are, instead im just waiting for the end, which im sure is near ;)

[odee]

how will the cut pistons hold up while towing? I have about everything to start my rebuild of a 6.5

[ogrice]

About the tach, you're right. I've just learned to live with the results. It reads way off. As for the gm-3 turbo, the thought didn't cross my mind to go with another one till after I was done and the truck was on the road again. As for cooling, i drive 80/20, fwy/streets. With the lower water pump speed and higher rated volume, in my mind, this will ensure that the pump will not cavitate and will still spin fast enough to make rated coolant flow. The main reason why i didn't go back to a stock pulley. Too expensive. Every where I looked, it was going to cost 200-250 bucks just for the damn part. Already had the Ford racing billet aluminum main pulley sitting in a box gathering dust. Dollars and cents made that decision.

In the last year i've driven from Los Angeles, CA to Seattle, WA 5 times(1200 miles one way). Each time with a vehicle in tow. I get 17-18gpm on the flat at 65 mph, and around 15-16 gpm in the mountains going 55 when climbing in 4th gear. If I put my foot into it(which i've done) it will climb the same hills at 70 or as far as I want to push it. I shaved .030 from the piston crown only to lower the CR and save money. If my engine dies because of a piston failing i'll be sure to post it. If someone were to shave some material from the piston crowns to lower the CR, you can still have the crowns anodized, ceramic coated, or whatever heat strengthening that you want as a margin of safety.