Shift, that is terrible. I'd be in complete freak out mode. Glad to hear the damage is not permanent.

 

Yes, they're compatible, actually at 214 cc/min they'll be right on with a decent bumpstick, dizzy timing, port matching, light valve work and hotter plug. If it was a 4.0 block you could add the 4.6 crank and rods..... just say'n. The 4.2 are harder to find.... If you leave everything stock it'll run a wee bit rich.

 

If my budget allowed I'd buy the top hatted GEMS block and do a 4.6 conversion. For sure. If I came across a 4.2 crank I'd seriously consider it.

I did a compression test today.

#8 120- -120 #7
#6 120- -100 #5
#4 120- -90 #3
#2 120- -30 #1

Obviously I've got a serious issue. I can't think of why number 1,3,5 would be low together. I guess I'll pull the heads and see if I've got a smoking gun.

 

did you do any oil in the cylinders to rule out rings?

My money is on burned valves though. That is what happened to my first Defender motor, to many rpms for to many miles.

 

Valves. Pretty common sight in the machine shop I use, it's a Rovah motor.

 

My thoughts where valves too but can't figure out why just those. *****. Oh well head needs to come off either way.

 

Oh and no. I just did it dry. I had no smoking. No oil consumption. I didn't think it was rings. I guess one could have broken I guess I'll find out

 

It never hurts to check but I still bet its the valves. Seems like high mileage Rover motors wound out for extend periods of time drop valves.

 

Well.... that'll do it...




No broken/burned valves. I don't know why compression would be lower on the number 2 and 4 pistons.

The engine is super clean inside. After some scrubbing I found the pistons have a curious 4.2 stamped on them. Could this indicate that this is a 4.2? Not a 3.5? It was sorta peppy for a 3.5. Any other signs I could look for?








I did find this lifter had an odd pattern on it too. Others are good. At least on this side.

 

Just based on the block number 38D, it looks like this is not a 3.5 but a 3.9 liter. You can always check the VIN too.