831-16 failure

Blue Oval Militia · #1 (**permalink**) 08-21-2010, 10:16 PM

I'm running a street/strip Mustang with a 306ci small block Ford, TFS heads, FW XE282HR-12 camshaft and 851-16 lifters. The car runs 12.10 N/A and consistant 10.70's on a 100 shot. Last night at the track while driving to the staging lanes for our 2nd qualifier we heard a loud ticking. We shut down the engine and started testing it. I found one of the lifters with the roller wheel detatched and the cam trashed. I pulled the engine out and tore it down today. 9 of the 16 lifters including the broken one have the retainng pin working their way out of the lifter. The one came out far enough to slam into the lifter bore and tear the ears off end of the lifter.
The lifters are about 7 months old. There is a total of 400 street miles and about 40 1/4 mile passes. The car is scheduled to race in PINKS ALL OUT in Norwalk, Ohio on Friday so this is very untimely.
My question is why did this happen? I can't be the only one. I assemble about 15 competition engines a year but this is the only time using these lifters. Double springs with dampers and 400 lb/in rate.

Blue Oval Militia · #2 (**permalink**) 08-22-2010, 12:38 PM

I have pictures so I need an email address for someone at Comp Cams to send them to. Is there a way of making this right? This is going to be an expensive repair for a part that was not supposed to fail and was used well within the capacity of it's design. The lifter bore is chipped on the bottom from the retaining pin but I dont have time to have a new block machined for this race. I'm going to have to hone the bore and hope for the best.

Blue Oval Militia · #3 (**permalink**) 08-23-2010, 10:38 AM

I'm sorry the title is incorrect. These are 851-16 Hydraulic Roller Lifters.

amick · #4 (**permalink**) 08-23-2010, 12:14 PM

Send the pictures to amick@compcams.com

Blue Oval Militia · #5 (**permalink**) 08-23-2010, 07:25 PM

Thanks for all the help today amick. I'm hoping the new valve springs do the trick.

amick · #6 (**permalink**) 08-24-2010, 09:54 AM

No problem at all. I am just glad I think we found the cause of your issues so it doesn't happen again.

Blue Oval Militia · #7 (**permalink**) 08-26-2010, 12:17 AM

Thanks again amick and Comp Cams for replacing the lifters and the advice on trying the different springs. We fired the car tonight and took it for a rip before loading it in the trailer and all is well. I'm expecting some good things this weekend at Norwalk and I dont think I would have found the problem without you.

amick · #8 (**permalink**) 08-26-2010, 09:54 AM

Thats great news. Let us know how things go and good luck at Norwalk!!!