Logo
FULL SITE MENU

Performance 1984 Trojan F32 w

K

king

New member
"1984 Trojan F-32 w/ crusader

"1984 Trojan F-32 w/ crusader 270's 1100hrs, always good maint, fresh water, except first two years were salt water.
Bought it Jan 2007. Comp was 135-145# max performance 30mph at 4100RPM. Not too bad.
Downhill ever since, with conservative operation.(120hrs) Comp now is 120-140#. Added oil to cylenders and it went to 140-155# Max speed 25mph, max RPM is 3700, with relativly clean bottom and 15X16" prop.
Are the engines just over the hill?
I'd appreciate any replys
King"
 
"It does sound like some ring/

"It does sound like some ring/cylinder wear is evident. Is there a lot of blowby?
Have the heads ever been serviced?
Are these RWC, running 140 deg stats?"
 
"Thanks for responding. Little

"Thanks for responding. Little or no blowby. That's the crazy part of it. On differential comp check, no air noise from crankcase. most noise from carb. Valve springs were down to 60-70# so I repalced them and valves are adjusted properly. Little or no improvement. Heads have not been serviced. I don't comprehend "RWC, running 140 degree stats" Engines were at 150 degree operating temp."
 
"hmmm, no smoking gun. I'

"hmmm, no smoking gun. I'd do a leak-down test first. That will tell the pressure loss culprit. At those hours, it's a bit early to call for a bottom end job, but a head rebuild is not out of the question. You will also be able to visual the cam for worn lobes."
 
"Differential comp check showe

"Differential comp check showed no significant crankcase air noise. Mostly air noise from carb. Little or no blowby. Low oil consumption. lifters look to be even lift, indicating no cam problem. I'd love to think that reconditioned heads would solve the power problem, but I cant ignore the low power, and the dry 120# versus oiled 145# compression."
 
"If you can do this in the boa

"If you can do this in the boat, i'd take the heads off and see what I can see. You can have a leakage test done on the valves/seats and check the bore for taper and scoring. Your testing has shown intake valve leakage."
 
But isn't it inevitable th

But isn't it inevitable that I have significant
ring/bore wear with the 120# vs 145#oiled compression readings. I have always been told that the oiled test would only bring the compression up 20 to 30# if there was ring/bore wear. Has anyone ever heard of the oil temporarily sealing the valves too?
 
"with an 84 vintage, i'd b

"with an 84 vintage, i'd be surprised if the exhaust valves still sealed. Back then they were expecting lead to help with the seats.

we also used 1000 to 1500 hours as the time to expect top end work; 1500 for the 'frequently used' and 1000 for the less than frequently used. Dave is right on and I'd bet a thorough valve job would help a lot.

If you do the top end and there's still an issue, at least you have spread the cost out so the bite isn't as big (at once)."
 
Isn't it inevitable that w

Isn't it inevitable that with 120# dry and 145# oiled compression on several cylinders that I have substantial ring/bore wear?
I would like as many replies as possible.
 
"Unleaded gas heads were norma

"Unleaded gas heads were normal by the mid-70s, so yours are okay.

The compression will always come up with oil in the cylinder, and yours aren't that bad.

Have you looked at timing advance to see if it;s getting it all? You need to mark the timing pulley at about 28 degrees advance, then boot it to 3,000 rpms and see what's happening. (Alternatively, you can use an advancing timing light and read the scale.)

Frankly, I wouldn't give up on them yet, unless cruising speed was not maintainable.

Jeff"
 
Back
Top