To Bore Or Not To Bore????
 

I'm replacing the Cracked 53 block in my truck finally!:yeah: I have a complete engine out of a bus, that has the stronger Mexican block. I want to completley rebuild this engine before I put it in my truck.
My question is would there be any performance gains by boring the cylinders? I'm thinking the added displacement with a helix2 cam, and a port/polished head, might help with cutting down on low boost smoke, and maybe lowering EGT's.
That leads me to my next question about pistons. Cummins pistons, or aftermarket? in what ways would an aftermarket brand of piston be better than an OEM piston? I'm also thinkin getting the pistons thermal coated.
sorry for the long post, I'd appreciate any input!:U:
Eric

IMO, and I am NOT an expert with Cummins, but I would think that boring them would only help, if you did everything. I believe you should thermal coat them. and as far as the diff between after makrket or OEM cummins pistons? IDK...

:w2::humm::pca1::U:

if your gonna go to that much trouble mite as well go with alumatherm pistons and carillo rods, and a full stud kit for head, rods, and mains, and boreing it out seemed to help my friends truck, but his truck is insane, [ more money than sense ]:c:

What are the advantages of alumatherm pistons??? (I'll do a search on them as well) In what department did the boring help you're buddy's truck, smoke, EGT's, power?? and how far did he bore his engine?
It seems to me as well that boring could only help, I read on another forum, that the bore to stroke ratio on our engines is better left alone. :humm:I'm just tryin to get as much input as I can. Keep the advice coming!:c:


Eric

Stock these pistons are insanely big and sweat torque already, I just don't see where the need would be to bore em unless you were lookin specifically for a sled puller or somethin. Just my uneducated opinion.:humm:

There's no performance gain to boring one of these blocks unless going low compression for meggaa big numbers (1,000+). Unless the block is scored or has damage just do a light hone on it and use factory pistons!

There's very few company's that design parts of the quality that the factory 5.9 carrys.

Rod's and crank are normally much stronger than aftermarket in the Non 3rd gen trucks.

If I remember some of the 3rd gens had some issues!

THERES A PILE OF TRUCKS MAKING 900+ on stock internals!!

#1 has some scoring, I can just catch the score marks with my fingernail, #6 has some visual score marks. the rest look fine and all of the pistons are the STD. size. I'm thinkin bore .010 and get 6 pistons from cummins, and get 'em thermal coated.
I did notice what looked like copper shavings on all 6 pistons, can anyone explain that? when I pulled this engine from the bus, I did see signs of dirt entry in the intake.
I really appreciate the input!

https://www.dieselbombers.com/genera...d-pistons.html

here is a good place in FL that i found for coating. might be worth looking into as the price seems real good.


copper.... couldn't that be valve guides?

Yes , Probably valve guide. Mahale makes a great piston as well! The coating is well worth the extra money!
10 Over will probably get it. Some try to just hone them out but in that case I would say bore it!

Valve guides, dunno why I didn't think of that. :argh:I did find an outfit here in Denver that does ceramic coating, so far I've heard nothing but good things about them, The outfit in FL would cost me about the same after shipping, BTW they do look like they're top notch! Havn't been able to find a price for Mahle pistons yet, I'll check with the guys at the machine shop when I drop the block off hopefully next week.

Hey guys, I'm not diesel owner, but I am a drag racer and I was researching thermal coating for my next race motor and came across this thread. I was wondering what the name of the place you found in Denver was. I live in Erie and would like to find a place close by so I don't have to ship everything off. I'm going to be doing the pistons and the combustion chambers. Thanks!

Applied Plastic Coatings INC.
5000 Tabor st.
Wheatridge CO. 80033
(303)424-9200
Check 'em out, they did an excellent job coating my exhaust expansion chamber for my snowmobile. keep us posted!:U:

My machine shop was able to bore #1 cyl, install a sleeve, and bore the sleeve to take a standard bore piston, hone the rest of the cylinders, and I only had to buy one new piston:U:
I'll drop my pistons off on mon. or tues. to get coated.:yeah::upup:

Please let me know how the coating turns out and what it cost you. Do you know the added wait of the coating? Does it require a rebalancing?

I don't think I'm gonna have to worry about the wieght of the coatings, i'm only gonna be turning a little over 4K RPMS. I'm guessing you're engine's turning alot faster, might be an issue for ya. I'm definatly checking into it, and I'll let ya know how my pistons turn out.:U:
Give them a call, I've been dealing with Ben, he's very strait forward.

They said I can get all 6 pistons coated for $390, and does not require rebalancing.

Nice. FYI, the diesel guys out here are using 12V cranks and rods in the CR trucks for strength. I thought the CR cracked cap rods were stronger, but I guess they have proven otherwise. I know all of the 900+HP guys have switched to 12V cranks, the Gambino brothers are running 2 sled pullers and both run the 12V cranks.

definetaly do the ceramic coating, i had my pistons and rod n main bearings coated for piece of mind:U:

I finnaly got my cracked block replaced,(9" crack on the pass side:madd:) The engine I rebuilt runs great.
I ended up installing Coated pistons, (thermal barrier coating on the crowns thermal dispersing/oil managing coating on the skirts and bottoms) HelixII cam, Hamilton 110# valve springs, decked/o-ringed block, decked ported/refurbished head, .010 thicker head gasket, balanced bottom end, fluid dampr, thermal coated Exhaust manifold, turbine housings and hot pipe.
Thanks to the Diesel Bomber members for their insight.

Out of curiosity why the helix instead of one of the HD cams?

There was no preference, really. At the time I bought the helix, I didn't even know Hamilton existed. And not too long after I bought the Formula1 cam, they dropped the price.:argh:

Call up Zach, It's almost worth switching. His cam's and Schieds cams are the ONLY cams that have shown any improvement what so ever in the 5.9L ! Real nice guy too! Glad you got your truck goin, Sounds like it was a heck of a project!

Good Luck!
Lucas

Oh well, a cam is kind of a big job, especially with the engine already in the truck, and I'm happy with the way my truck runs now. Now that she's breakin in some, I'm noticing much better throttle rsponse, and 100-200* drop in egt's across the board.
Thanks Lucas.
Eric.