LLY: Broken Crank,need opinions on new build sheet

dirty_max

Member
Jan 27, 2013
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eureka il
I would reconsider the ma mounts. if I had to do it over again I would just bolt the stock ones or just run one on the drivers side. they make for a lot of vibration, and bolts fall out of things and your interior pieces will vibrate and drive you nuts.
 

Chevy1925

don't know sh!t about IFS
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Oct 21, 2009
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Delippied lb7s have been in countless 1000hp trucks over the years, not just Brian's

yup, it was said a long while back stock delipped lb7/lly pistons would be relatively reliable up to 800hp. this is not to say they wont break nor that they will last forever there as engine setup will dictate that (ie, running lots of fuel and not alot of air and so on).

I would reconsider the ma mounts. if I had to do it over again I would just bolt the stock ones or just run one on the drivers side. they make for a lot of vibration, and bolts fall out of things and your interior pieces will vibrate and drive you nuts.

x2, thats why i stayed with my bolted mount vs those when i did my motor.
 

Cknight199

New member
Aug 23, 2012
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I thought lb7 deliped pistons are the same material and design that comes from Mahle with their race CAST pistons.

I would go fixed vane for sure. I've been through a 4094, 72mm 4094, and s475 and the s475 was way more fun and easier to make power on. Plus they look much cleaner, and the engine sounds healthier with them IMO. :eek:
 

Chevy1925

don't know sh!t about IFS
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Oct 21, 2009
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Mahle race cast are not the same as lb7/lly though they still have failed at 1000hp and not just on one or two truck
 

dirtymax36

2nd place is last
Apr 11, 2013
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Probably going to stick with De lipped lb7s. Truck will have an s468 billet on it with 60%s. Do you think the 85% pump I have now will be enough to supply 700 or more until I do dual fuelers down the road?
 

dirtymax36

2nd place is last
Apr 11, 2013
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Thanks so much for all the help guys. I plan on tearing it apart and posting pictures soon
 

Utahski

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Oct 20, 2008
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There are 3 people I know of on this board who were way over 900hp with rods and de-lipped uncoated LB7 pistons. One pulling truck made 980 on a mustang dyno....he ran it hard for 4 yrs and the thing is now unused but still fine. Those pistons already had 130K miles on them when he built the engine. Another LB7 was about 950, ran mid 10's, still being driven daily. Another was also around 950 and ran mid-low 10's......that engine has since been built however I don't believe he ever had piston problems. Keep in mind that much power is hardly ever used, you really can't except on the track.
 

S Phinney

Active member
Aug 15, 2008
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Quncy, Fl
If you are having to put much money on the machining for b pistons by the time you are finished you would be better served to start from new. The new will come with rings and pins. Checking the pins on your old pistons to make sure everything is good and all is part of it. Most guys don't go the extra mile to make sure they have a good base to start from. I have done both and won't recommend using stock delipped pistons.
 

dirtymax36

2nd place is last
Apr 11, 2013
367
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My neighbor is a machinist and will be doing this pistons for very cheap vs. What other prices would be
 

dirtymax36

2nd place is last
Apr 11, 2013
367
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Anyone know of a good place and price on getting this motor balanced? Preferably around central Illinois.

Thanks for all the help !
 

carpenca

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Dec 17, 2010
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Caleb, ultimately dyno numbers are a marketing tool and I get that. I also realize they're great for comparison purposes as well. I don't doubt for one second that you guys rate your turbos on the HP you see on the dyno. So please don't take any offense, I don't think you're lying. I simply don't think the trap speeds I've seen match the HP they're rated at. Don't get to upset with me, I still want to get one of your data logging setups one of these days.:hug:

Ok, so if its all about trap speed. My truck weighs 7000#'s on the nose. I trapped 108 MPH in the 1/4. How much HP am I making? Answer quickly, I'll be dynoing it tomorrow.

Let me know when you want to get a datalogger, I'll get you setup.

Caleb
 

ikeG

Oughta Know Better
Apr 19, 2011
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I would reconsider the ma mounts. if I had to do it over again I would just bolt the stock ones or just run one on the drivers side. they make for a lot of vibration, and bolts fall out of things and your interior pieces will vibrate and drive you nuts.

If you're going to just bolt the stockers, make sure to use grade 8 bolts. We didn't and the driver's side broke the heads right off.
 

Chevy1925

don't know sh!t about IFS
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Oct 21, 2009
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If you're going to just bolt the stockers, make sure to use grade 8 bolts. We didn't and the driver's side broke the heads right off.


One 9/16 grade 8 bolt dead center of the mount seems to hold up really well. Been that way in my truck for the last 6 years
 

Utahski

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Oct 20, 2008
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Northern Utah
Ok, so if its all about trap speed. My truck weighs 7000#'s on the nose. I trapped 108 MPH in the 1/4. How much HP am I making? Answer quickly, I'll be dynoing it tomorrow.

Let me know when you want to get a datalogger, I'll get you setup.

Caleb


Mine did 109 when it was dyno'ing about 545 at 2,000' higher elevation. The formulas say 108 = 575hp.
 
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