Engine build LB7 with LML parts

PureHybrid

Isuzu Shakes IT
Feb 15, 2012
3,492
472
83
Central OH
I just want to know where the oil is coming from...I hope I don't have to do a rebuild, I will do it, but I would rather drive it then to a rebuild. How bad is it to reuse a stud...

Arp studs are reusable many times over. I would pull the exhaust manifolds and see what port the oil is coming from and then start on that cylinder with the compression test.
 

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<<<IT WORKS
Mar 1, 2013
1,780
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48
Des Moines, Iowa
I did a compression test, Zero on #6. Before I did a compression test I pulled the valve core out of the test plug and blow air into the cylinder with the filler cap off. All the air came right back out the top, now i wonder how big the hole is.:confused: If I just do a rebuild kit(Pistons, bearings, seal rings), are the pistons as strong as original LB7 piston?
 

TheBac

Why do I keep doing this?
Staff member
Apr 19, 2008
15,610
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Mid Michigan
Sorry to hear. Hopefully you dont find any more damage when you do your teardown. For what you want to do, cut LB7 pistons should work ok. But....how much self control do you have? Is 700rwhp where you'll stop? If not, go another route on pistons.
Rods should be your #1 priority though.
 

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<<<IT WORKS
Mar 1, 2013
1,780
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48
Des Moines, Iowa
The engine has been out ones from the looks of the engine(painted all black) and the looks of all the stuff I have removed so far. So I am hoping for some more goodies in the engine I don't know about. As for rods, who's got the best price on them or can get the best price?
 

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<<<IT WORKS
Mar 1, 2013
1,780
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Des Moines, Iowa
Sorry to bring this thread back to life, but I don't fell like starting a new one.
My build as of right know is consisting of stock keyed cam and crank, Cut, coated, and releved lb7 piston, lbz rods, and Hamilton valve springs. The truck already has a S366, dual CP3's, and a built tranny. I am looking a doing 40 overs stick, but may stay stock. Maybe later it will get rod, but not now. How power could I go safely?
 
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adeso

wait, what?
May 30, 2011
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Minot, ND
Not much more than what you had, maybe 650 if you keep the tq down but that is pushing it. Add up how much you have into machine work and parts, and know that you could do 800 HP no issue if you spent another $2200 on rods.
 

adeso

wait, what?
May 30, 2011
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Minot, ND
I'm not trying to be a dick, I was doing the same thing with my build, then realized it isn't worth doing a build without doing rods. Only way it makes sense is if you don't have the cash, and you own the machine shop or get the machine work done for free
 

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<<<IT WORKS
Mar 1, 2013
1,780
37
48
Des Moines, Iowa
Not much more than what you had, maybe 650 if you keep the tq down but that is pushing it. Add up how much you have into machine work and parts, and know that you could do 800 HP no issue if you spent another $2200 on rods.
Good point, but I don't have that much $$$$$ to throw in to it. I never bored it over so there is still some marks on the cylinder walls and i am reusing the bearing(they are not even broke in), so I am doing this cheap. So far I don't even have the price of rod in to it. It may bite my in the ass late, and then i am planning on doing rods.
I am just trying to see how much power I could safely with the LBZ rods. I am still trying decide what to do about injector. I am trying to find out how much power I can get with stock injector or with 40 overs without bending the rods.
 

adeso

wait, what?
May 30, 2011
1,569
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Minot, ND
If your sticks are good now, I would keep them and upgrade when you do a good build. Or if you need new ones I would think about going 60 over just know that you have to be very conservative on the tuning and you only have that size to save money when you do a real build. Watch out where you get your sticks from, seems like one 60 over is nothing like some other 60 overs
 

jkholder09

New member
Jan 8, 2012
1,188
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0
Maryland
The lml stuff is very inexpensive. Out of 64 pistons i got one that wasnt round and did not fit the hole.
It was 14 grams heavier than other 7.
My point is check it all very careful even tgough its new
 

cafryer

New member
May 5, 2011
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Utah
You are doing main studs but not having any machine work done? If so thats not a good idea also you need to have your rotating assembly balanced.
 

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<<<IT WORKS
Mar 1, 2013
1,780
37
48
Des Moines, Iowa
The engine has been out ones to get the crank balanced because it got a 12 bolt ATS flex plate, that is when it got its main studs. I am looking at getting Idaho Rob to tune it. I am planning on balancing the rotating assembly, just haven't got that far. As for injectors I am looking at Energy.
 

adeso

wait, what?
May 30, 2011
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Minot, ND
I would keep the stock sticks and use the money for rods and all the right machine work, then upgrade the sticks when I got a chance. Not trying to tell you what to do.
With the mains, if you put studs in it changes how it lines up and won't be right (read spin a bearing and break the crank) so you really need to line hone it with the new tq specs
 

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<<<IT WORKS
Mar 1, 2013
1,780
37
48
Des Moines, Iowa
So now that I took the main studs out I need to re line hone it after it was done for the new bearings not that long ago? The main is going back to gather the same way came out.
 

adeso

wait, what?
May 30, 2011
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Minot, ND
ohhhh so it already has main studs in it? I missed that. that is really odd that you ended up with main studs but stock rods
 

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<<<IT WORKS
Mar 1, 2013
1,780
37
48
Des Moines, Iowa
As of right know I will be staying stock on the injectors and just replacing the two bad ones i have. What do you guys think will be a safe power level for the stock LB7 injectors and LBZ rod? I am looking for some input on these numbers, as of right know ATP will be tuning the truck. With is set up what would my power levels for street and tow be.