How durable is a KZ motor?

Here's a recent actual accounting of how durable they are.

1327 big block that was all kinds of screwed up running 6.28 1/8th mile.

The combo:

1327 Big Block with street compression J pistons

Andrews 8X cams

86-88CFM @10" head with stock valves - shaved down so far they cut into the intake valve seats.

38mm Trons [not even close to dialed in]


What was wrong with the motor?

2 overlapped oil wave rings

All 4 intake valves where hitting the pistons because the intake cam was 2 way over advanced. The motor had over 300lbs static compression

Block was not machined properly for the cam chain shoe. That caused the front idler to be dragging and not spinning free.

The piston valve relief cut outs looked and measured up to show they were never machined properly from the manufacturer. They measured 35.5mm at the widest section on the intake relief pockets.

The cam new cam chain was so beat after about 10 passes that you could hold it and 5 or 6 links would stand straight out!

In short this thing was an absolute abortion.

It's all been fixed now and if it doesn't rain next Friday we'll find out how it runs now..

Bottom line is this. Aftermarket block was not machined right and neither were the pistons. Inexperienced guy assembled the motor and didn't notice any of those problems.

I'm not naming names on the parts. 'nuff has already been stated that you should know if it's aftermarket...you need to look it over really well before you call it good.

I'll say this much IT WAS NOT APE COMPONENTS



Larry C

Soooo, pretty durable then? :laugh:

and it was running 6 sec. 1/8ths? Damn,there is hope for me yet.Lol.bj