work in progress

iTrader: (2)

I installed a 408 in my truck yesterday, and it started knocking about 5 minutes after I started. I pulled the ignition fuse and turned it over until I had oil all through the motor. When I started for the first time, I had 42 psi of oil pressure almost immediately. It idled great, and there wasnt any rattling at start up. I brought the rpms up to about 1700 (idle was 700), and the motor starting stumbbling then died. I started it again, and it knocked immediately. Has anyone else spun a bearing on a new motor? What could have been the culprit? All I know is that I'm tired, sun burned and don't want to pull this damn thing.

Tootall

iTrader: (79)

how did you install your lifters?

work in progress

iTrader: (2)

I had the motor built by Kotzur Racing. The motor didnt make any noises at startup, it had 42 psi of oil pressure, starting shanking and then died. When I started it again it was knocking, but I still have great oil pressure.

Tootall

iTrader: (79)

it could be all kinds of things

Rockers not torqued right
lifters not being soaked
crank no being polished, or turned too far - not the right sized bearings


Have you tried to locate where it's coming from?

Flyer

iTrader: (1)

If it's still got good oil pressure, then it's prolly not a bearing.

Pull the valve covers off and see what gives.

Lurius

iTrader: (7)

I dont think they would have turned his crank any on a 408, odds are they had to use a new crank being that theres no factory 4" stroke cranks.

-Lurius

work in progress

iTrader: (2)

I dont think it is a bearing either. I am wondering if I had a piece of debris from the last motor lodge it self in the intake that is now lodged in to the head and getting hit by the piston. I am going to pull the heads off to see if there is any damage in the top of the motor. I was also thinking that a rod bolt wasn't torqued properly and maybe hitting the block.

Lurius

iTrader: (7)

Why not contact the builders? It is likely something they did that is causing knock. Ask them to look it over as warranty work or something.

-Lurius

custom 68

iTrader: (8)

exactly what Lurius said if you tear into it they probably wont warranty it or fix it any more. They can take care of it.
Dave

Tootall

iTrader: (79)

After spending all of that money, I'd go after the builder first. I'd go as far as the lifters, and that's it