Billet Injector hold downs???

[ZeroGravity58]

Anyone here having problems with stock hold downs on the lly/lbz/lmm? I swapped nozzles a few months back and haven't had a problem until the other day. I ran the truck hard about 6 times making a few test passes now I have a tick on the pass side. I've only put probably 500 miles on it since changing nozzles and I used new copper washers. I think I may have pushed an injector. I used stock hold downs and bolts torqued to 25 lbs. I have a set of 200 over I'm thinking about swapping in, should I get billet hold downs? By the weight/mph the truck should be in the mid to upper 700's

 

[juddski88]

I have stretched many stock bolts at 550hp. Bent stock hold downs at the same power. Also make sure the sealing surface in the bore is not eroded after an event like that. I have had to replace heads due to erosion and grooving.

 

[ZeroGravity58]

I have stretched many stock bolts at 550hp. Bent stock hold downs at the same power. Also make sure the sealing surface in the bore is not eroded after an event like that. I have had to replace heads due to erosion and grooving.

I'm hoping I did not hurt the heads, I made a few passes and brought it home and parked it. I went to drive it yesterday and when I started it I could here it ticking so I drove the lbz. Guess I'll order a set of the socal hold downs when I swap injectors here soon. Seems like some get away with stock hold downs and others don't???

 

[08lmm72mm]

Did you use a new bolts? I believe they stretch after 1 use. I had an issue changing my injectors with 1 of them last time. I never blew out the injector hold down bolt hole with compressed air and it must have gave a false torque reading.

 

[ZeroGravity58]

No I did not use new bolts. I cleaned them up and put a small dab of arp lube on them and torque them

 

[Dozerboy]

I think they need to be retorqued after a few heat cycle. Maybe not at 25lb though thats a liytle high IIRC. I'm in the 700hp range and lifted 1 injector and had a few other that where a little loose after doing injectors on my LBZ.

 

[ZeroGravity58]

I never did recheck the torque on them. I'm going to let it sit and order a set of socal hold downs. I'm pulling the injectors anyway to swap to a bigger set. I want to make it the last time I pull them until winter when I pull the motor to build the bottom end. Hopefully it last this year....