RE: TO20 engine rebuilt time

[FergFord]

Thanks for all of the advice so far.

I let the old girl run for about 10 minutes then did the compression tests. After warmup I removed the tube from the air cleaner and fully opened the throttle to run the tests. Battery died prior to wet tests so block was a little colder but still warm enough that I would not want to touch it for a long time.

The compression numbers: (from front to back) wet in brackets

#1 70[80] this is the one that oil fouls.
#2 80[90]
#3 50[60]
#4 50[65]

Also I get considerable abounts of oil out of the breather tube.

Whats next?

BTW. Is there a good way to post pictures to this site so that people can see what is happening?

Mark

FergFord since I have a '50? TO20 and a '53 Golden Jubilee

 

[Jerry/MT]

After reviewing your compression test results, you're in need of at least new rings. #3 & #4 may need valve work also or maybe it's a headgasket leak. With these compression numbers, lot's of blowby is not surprising.

Now comes the tough part. How much are you going to do? What's your oil pressure look like with the engine warm and idling at 400 rpm and 30 W oil in the crankcase? If it's less than 15 psi then you'll need an oil pump rebuild and/or new main bearings. As long as you arein that far, should you do the rod bearings also. You'll need work on the head, etc. You've got some decisions to make unless $'s aren't and issue. If you can do the disassembly/reassembly work yourself and just let the machine shop do the machine work, you can save quite a few $'s and have a nearly new engine.

Yes, you can post pictures on this sight but not being that high tech myself ( don't have a digital camera, yet), I can't tell you how.

Good Luck on whatever you decide to do.

 

[FergFord]

Jerry,

My oil pressure is usually around 20 PSI.

 

[Jerry/MT]

The manual say as long as the oil pressure at operating temperture and idle rpm (400 rpm) is above 15 psi, you're good to go. The normal operating oil pressure on a new or remanufactured engine is between 25-30 psi. Mine holds 27 psi hot or cold, idle or max rpm.

You say yours is 20 psi. Is that with 30W(or 10W30) oil and at idle rpm(400 rpm)? The weight of oil can influence this and some folks put 20W50 or straigt 50W in to get their oil pressure up. What do you have at higher rpm?

IF you are at a steady 20 psi across the rpm range with the engine warmed upwith 30W oil, you still have some clearance left in the mains and/or your pump has some wear but if you don't want to do the lower end/pump, in my opinion, you've got some time. You'll have to do rings and a valve job as a minimum.

 

[FergFord]

Jerry,

It is 20 psi all of the time hot or cold. Using both 30W or 10W30 does not matter.

When really cold it starts at about 15 then goes to 20.

 

[Jerry/MT]

When you're in the bottom taking off the rod caps to pull the psitons, check the lube oil relief valve and make sure it's not sticky. If you don't want to do the lower end now, you can wait a while with the pressures you report.