Advice on rebuilding a 1098
Posted: Thu Jul 23, 2009 8:21 pm
Dear all,
My old 1963 Trav's got a Gold Seal engine put in about 1972 and is showing its age. I've done 57K in it and I believe the engine's done well over a 100K, and its probably unwise to tune this aging beast.
It goes well, will cruise happily all day at 65 (true) even with a small trailer and it returns 35+ mpg. However, I only get 300 miles to the pint of oil if I'm careful, and driven hard its down to 200. Oil pressure hot (210F) is 42 psi max and down to 8 psi on hot idle. The valves were checked when an unleaded head was fitted 13K miles ago and at the moment the compressions cold with the the throttle wide open are (front to back and the second figure with oil squirted thro' the plug holes) 162/178, 175/198, 172/181 and 168/175 psi.
The pistons are 20 thou oversize. I checked the bigends and the two front mains only 2k ago and they were within half a thou of ovality i.e. as near a round as you can measure from beneath with the crank installed, and they had no grooves.
The crank is 40 thou undersize. I replaced all the bearings but, of course, can't get at the rear bearing. I think it all has to come out with the g'box, clutch and flywheel off to get at this one Am I right?
A new oil pump would help too, I think.
I'm inclined to get it all out, fit a new crank, bearings, pump, etc and rebore. But would only a new pump and rear bearing sort it out?
But it goes so well, that perhaps I should buy another and build up separately.
What's your advice? Regards, MikeN.
(I'm off to Exeter tomorrow (240 miles round trip), so if you get passed by a quick Trav and trailer and sprayed with oil - its me!)
My old 1963 Trav's got a Gold Seal engine put in about 1972 and is showing its age. I've done 57K in it and I believe the engine's done well over a 100K, and its probably unwise to tune this aging beast.
It goes well, will cruise happily all day at 65 (true) even with a small trailer and it returns 35+ mpg. However, I only get 300 miles to the pint of oil if I'm careful, and driven hard its down to 200. Oil pressure hot (210F) is 42 psi max and down to 8 psi on hot idle. The valves were checked when an unleaded head was fitted 13K miles ago and at the moment the compressions cold with the the throttle wide open are (front to back and the second figure with oil squirted thro' the plug holes) 162/178, 175/198, 172/181 and 168/175 psi.
The pistons are 20 thou oversize. I checked the bigends and the two front mains only 2k ago and they were within half a thou of ovality i.e. as near a round as you can measure from beneath with the crank installed, and they had no grooves.
The crank is 40 thou undersize. I replaced all the bearings but, of course, can't get at the rear bearing. I think it all has to come out with the g'box, clutch and flywheel off to get at this one Am I right?
A new oil pump would help too, I think.
I'm inclined to get it all out, fit a new crank, bearings, pump, etc and rebore. But would only a new pump and rear bearing sort it out?
But it goes so well, that perhaps I should buy another and build up separately.
What's your advice? Regards, MikeN.
(I'm off to Exeter tomorrow (240 miles round trip), so if you get passed by a quick Trav and trailer and sprayed with oil - its me!)