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-   -   Duramax build and the machine shop. (http://www.duramaxdiesels.com/forum/showthread.php?t=77469)

Frogman1 08-31-2017 06:23 PM

Duramax build and the machine shop.
 
Hello all and firstly, many thanks for the top notch guidance I have received from other posts as well as the guidance from high end engine builders and mechanics.
I am in deep on an LBZ build with the goals of an enduring engine with strong fuel economy and the tuning options of higher than the basic 500-600hp safe zone.
I have an LBZ with about 76K on a non modified, easily worked farm truck, and from my disassembly and inspection it is matching. I am shooting for a max possibility of 800hp on very rare occassions in my Hummer H1(no sled pulling or drags, less the local red light rice burner kids here and there). Just ordered PPE 16.5:1 Mahle performance pack pistons and Carrillo rods. Running a Garrett GT4088R solo. I have dropped the block off today at a trustworthy machine shop who will be clean and fluxing for $100 and boring over to .020 and replacing the cam bearings for $250. They suggested two highly recommended additional options for the LBZ, a heavier block. I'm looking for knowable guidance on lasting, performing rebuilds.
Firstly, they recommended an additional "pressure test" of 80psi to look for pinholes from the water jacket side and from the cylinder side. I asked PPE and they said it was not a concern with the harder, heavier LBZ. I have not heard of the need for this during other builds on various forums and sources, and remember, my engine is low mileage, low wear, high compression (380-400psi per cylinder) and was not needing ra rebuild less my desire to make it heavy duty for higher torque/HP capable possibilities. Does anyone have any input on this PSI check specifically?
My second machine shop recommendation, when I told them I had ARP main studs on the factory main caps was their absolute recommendation for me to have a "Line Bore" done for the crank journals, or stick with the factory bolts. The owner admittedly said there was a D-max guy in here last week with his build that the block owner measured and stated he did not need the line bore done as the studs did not distort the lobes out of specs. I have no plans of going in an additional grand for this only to have to then get eccentric bearings to fit my factory crank and hope it holds evenly all the way around. I do plan on having them do the engine balance once I even up the weights on the PPE PerformancePak piston kit and Carrillos.
lastly, I was looking at going with the harder Clevite "H" or even better, "HK" vice "P" in the standard size for bearings for the crank, rods, and cam. Any experienced words on this to help me with the forever lasting engine? Thanks very much for all of your help.

Ralph

gmduramax 08-31-2017 06:37 PM

Send you pistons back and get fingers. Run away from the first machine shop. You will for sure need the mains line bored

Frogman1 08-31-2017 07:01 PM

Hahaha! I was vey strongly going to go with Fingers from all the info I had gathered up until last night, as they would be able to give me closer to 17:1 or higher compression to a somewhat safe point. I decided for the steal of a price, I would stick with 16.5 PPE de-lipped Mahle's for a grand or more less because I looked at what a high end pro builder/racer on here and Youtube was running successfully at 15.5:1.
Thanks for the info on the boring.

Best,
Ralph

Awenta 08-31-2017 07:01 PM

^ that. Line bore yes. Also deck plate hone.


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Frogman1 08-31-2017 07:10 PM

Thanks. They are deck plating, bore and honing to .020 over. Line boring the main isn't what I was hoping to hear, but apparently, it's a must do if I'm going to use the ARP main studs. Thank you for the help.

TheBac 08-31-2017 07:38 PM

You would understand the need for the line bore if you torqued the mains down with the studs without it.
Personally have seen it, freaked out when the crank stopped turning easily, laughed our butts off at it when we figured out what happened, then had the mains bored and all was well.

Frogman1 08-31-2017 07:49 PM

Ouch! At least you had the sense to check and catch it before reassembly! That was kind of my plan as well before the forum inputs. It could have been pricey drama for me hand I gone forward without asking for guidance. Much appreciated!

gmduramax 08-31-2017 08:01 PM

Quote:

Originally Posted by Frogman1 (Post 1077232)
Hahaha! I was vey strongly going to go with Fingers from all the info I had gathered up until last night, as they would be able to give me closer to 17:1 or higher compression to a somewhat safe point. I decided for the steal of a price, I would stick with 16.5 PPE de-lipped Mahle's for a grand or more less because I looked at what a high end pro builder/racer on here and Youtube was running successfully at 15.5:1.
Thanks for the info on the boring.

Best,
Ralph

Hope you enjoy changing pistons every 30,000

PureHybrid 08-31-2017 08:20 PM

Don't think that 4088 is going to net 800hp. I'd suggest skipping the main studs and run new bolts. If the bores check out true, I'd also run a std bore. Unless money is no object ;)

Frogman1 08-31-2017 09:10 PM

Pressure test
 
Thanks for the advise. I've been thinking it over with the support of your and other's posts. New factory bolts seem to be the smartest option for the money. ARP bolts plus line bore would end up at $800 plus what ever additional cost oversized bearings run, not to mention that the block would forever be resized and might or might not be done correctly. Plus... if I'm going that far, why not bore new HD main caps and put on a girdle with the longer ARP studs. It would never end and I'm not looking at ridiculous HP to need that. Good call.

Any ideas about the bore .020 over followed by a "pressure test" in the cylinders and water jacket looking for pitting leaks in the cylinder walls? I searched and found it done on Youtube with a 1933 ford block. From my view for the Duramax It sounds a lot like needing to put new fresh air in your tires every year because the old air gets stale. http://www.duramaxdiesels.com/forum/...cons/icon6.gif

Awenta 08-31-2017 09:30 PM

If you got 400 compression in each hole I wouldn't worry about it. If you were leaking you would know it. But after a bore it wouldn't be a bad idea.

Now on the line bore. I would recommend it no matter what path you go.


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Frogman1 08-31-2017 10:18 PM

Thanks Awenta. I figure if I tell him not to take my money for the pressure test, I'll probably be going back and paying more for a sleeve or sleeves from a well placed group of holes made during the honing;) have a great one. All say a line bore is a must. Maybe I'll be able to negotiate the price.

PureHybrid 09-01-2017 01:26 AM

The shop should be willing to torque the mains and check the block. Even if it needs a light line hone you can still run std bearings without negatively affecting bearing crush.

Yes it's nice to have every part machined and made perfect, but not everyone is building a race engine and we have budgets.

A little time spent measuring / inspecting the block before any work is performed will allow you to skip unnecessary steps and save money in the long run.

ikeG 09-01-2017 05:32 AM

Just had a lb7 block fixed that had a pin hole in two bores. If you had pin holes, you would know. It would burn coolant and also get it in the oil.

Frogman1 09-01-2017 07:35 AM

Thanks for the tip. I'll bring the ARP studs with me and see what they can do as far as checking to see how far out of round they distort.


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