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.
LLY: Broken Crank,need opinions on new build sheet
- Thread starter dirtymax36
- Start date
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).
x2, thats why i stayed with my bolted mount vs those when i did my motor.
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.
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.
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
Oh okay thanks for the clarification.
OP if it is in your budget to get new pistons, I would recommend fingers oval pistons.
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?
Thanks so much for all the help guys. I plan on tearing it apart and posting pictures soon
Yes.
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.
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.
My neighbor is a machinist and will be doing this pistons for very cheap vs. What other prices would be
Anyone know of a good place and price on getting this motor balanced? Preferably around central Illinois.
Thanks for all the help !
Thanks for all the help !
How far you willing to drive?
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
I'd say between 600-650 at the wheels. What turbo are you running?
yes Caleb what turbo(s) are you running? I'm about to order a FPE 68 or 72 since I can't get my hands on that compact kit lol
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
I made 987hp on a dyno with delipped LB7's. Broke the crank the next day. Upon inspection, 4 skirts were cracked. Got Fingers pistons now.
Mine did 109 when it was dyno'ing about 545 at 2,000' higher elevation. The formulas say 108 = 575hp.
Last edited: