View Full Version : Engine builders question

09-17-2002, 10:14 PM
Iím rebuilding an engine in an ITB Rabbit. After overheating the oil and loosing oil pressure the engine started to knock. After tear down I found #1 & #3 rod bearings were the problem. I noticed that the rods on those two cylinders were discolored from the heat. Otherwise they look fine. I know I should just pitch them but Iím on a pretty tight budget. Can they be used without great risk to failing later?

Bill Miller
09-17-2002, 11:06 PM
I've got an extra set of rods from a Rabbit GTI I could sell you. Shoot me an email a [email protected]

MARRS #25 ITB Rabbit GTI
SCCA 279608

09-18-2002, 12:57 AM
#3 rod bearing is always the first one to go if you loose oil pressure.

Been there, done that, twice.

I to have some rods if you and Bill can't connect.

[email protected]

Tim Linerud
San Francisco Region SCCA
#95 ITB GTI, GP for 2002

09-18-2002, 07:01 AM
Do not simply re-use the rods "as is". If you cannot afford to get them re-sized at a machine shop, try and put in better used ones.

Just putting in new bearings will simply delay the inevitable and you will always be uncertain when the inevitable will strike!

09-18-2002, 09:39 AM
Why does a motor like ours (A1-8V) lose oil pressure?

I just saw this thread, and well gee, my #3 rod just went thru the block.

No missed shift, happened about 4500 to 5000 rpm. Oil pressure had been fine, but I was not looking at the gauge when the 'big bang' occurred.

I have not torn that blown motor down yet, but instead am just rebuilding another motor.

I had heard a faint knock in the old motor, knock that seemed to coming from down deep, but only at idle. Someone told me that it was piston slap, and not to worry about it. Something like "the motor builder did that on purpose to 'loosen up' the piston to reduce friction". I figured the knock (after the fact) was a bad rod bearing, and it just finally let go.

But, what I don't know is what exactly happened.
Did the rod bearing get beat out of shape, then the bearing lost it's oil film, then the bearing overheated, then broke?

If that is what happened, then I guess loss of oil pressure was not the real problem, per say.

But I donít know.

Any hints?

ron vaughn
83 vw A1 itb