FE-FC Holden Discussion Forum

Technical Board => General Technical => Topic started by: rickjen on November 26, 2013, 11:39:11 AM



Title: pistons and bearings
Post by: rickjen on November 26, 2013, 11:39:11 AM
Hi all
Just opened up my grey motor of my FC wagon, "37+k mileage??". Measured bore and piston 3.05in 77.5mm. Conrod bearing 1.73in 44mm marking on bearing "020 Holden R08". question is what size should I order in both pistons and bearings. little confused as book says's 3.00in bore!!.
PS all pistons, cyl and head look in in near perfect order no marks or evidence of cracks just a little bit of carbon and rust, has been sitting for 37years
regards
rick


Title: Re: pistons and bearings
Post by: hsv-001 on November 26, 2013, 12:39:22 PM
Scrape the carbon from around the top of the cylinder above where the piston ring stops and check for a ridge that will tell if 37k is first lap of the speedo . I would say not if the big end bearings are .020 and didn't you say it was stored for some 30 years . So it may have been driven around the clock once. Anyway the ridge will give some indication of wear and if you position the piston in the centre of the cylinder in its correct alignment you can check clearance [wear] . It would be great if the 37k was original . You would probably be able to use the original pistons but the bearings make me wonder . Cheers Haydn


Title: Re: pistons and bearings
Post by: Harv on November 26, 2013, 01:37:00 PM
Rick,

What is the engine number stamped into the block?

Roughly speaking, if it is an earlier FX-FC block (no prefix, or "L" prefix stamped into block), then the (unmolested) bore should be 3". The later FB-EJ blocks ("B" or "J" prefix) had 3.062" bore.

3.05" is an unusual measurement. Typically you would measure 3.00", 3.01" (10 thou over), 3.020" (20 over) or 3.04" (40 over... nearly on the water jackets) for early blocks. For later blocks, typically 3.06", 3.07, 3.08" or 3.10".


Regards,
Harv


Title: Re: pistons and bearings
Post by: rickjen on November 26, 2013, 03:42:29 PM
Harv/Haydn
Thanks for your comments, there is doubt on once around the clock or not cannot really verify, the son seems to think it is original mileage going on the rest of the car, very, very little rust and very straight with little wear and tear. The engine number is L385970, cleaned one of the pistons "7406476" when I did my own search the book say's FB pistons. So if I got it right ( which is rare for me) a different block, 20thou on the crankshaft missing, and FB pistons, Main bearings standard no markings. No ridge on the top of the bore after cleaning  rust rings, Crankshaft, bearings, bore and camshaft all look OK without marks. Will clean up completely and do "wear" test.
My guess motor taken out, bored and rebuilt replaced in car and not long after parked and left for 37 years ?????, hard first 30,000 miles or around the clock once, judging by the rest of the car could be the former.
Plan A, replace conrod bearings "with 020", mains, rings to suit 7406476 pistons, replace camshaft gear with metal one, clean out all water and oil pump passages,get head checked and converted to ULP, new gaskets and cross fingers !!
Plan B , have not got one yet.
Rick


Title: Re: pistons and bearings
Post by: hsv-001 on November 26, 2013, 04:15:50 PM
Sounds exactly as I would do . Waterpump and welsh plugs and check clutch plate as it goes back in . Keep us posted . Haydn


Title: Re: pistons and bearings
Post by: Harv on November 26, 2013, 04:52:33 PM
L385970 means your FC wagon has an FC engine in it, which started at a 3.00" bore. 7406476 is a standard FB-EJ piston (3.06" diameter). Sounds wierd that it was bored 60 thou at it's first overhaul... must have been a pretty major event that preceeded it  ??? Wonder it isn't into the water jackets.

Cheers,
Harv


Title: Re: pistons and bearings
Post by: ACE on November 26, 2013, 04:54:44 PM
G'day Rick,
Going by the engine number it is out of a FE.
ACE  8)


Title: Re: pistons and bearings
Post by: Stewy on November 26, 2013, 05:58:15 PM
I agree ACE, L385970 puts it at late September 1957.
I have the original block out of Fergus which is still 3 inch bore and November 1957.
They all have a story to tell and finding out what happened could be a long journey.
Good Luck  :)


Cheers Stewy   8)


Title: Re: pistons and bearings
Post by: john253a on November 26, 2013, 06:21:44 PM
side note while its out
the oil filter mod for full flow is mod worth looking into

not sure how far you plane to go or what $$$ your looking at spending,

the head idd stallite insert the exhaust (about 50 per cylinder) on top of reco (if sticking with a single carb just a light debure or clean up)
the get the lifters and cam ground/cleaned up
light hone the bore (old style eggbeater drill works wonders, if not cordless on slow to get a nice figure 8)
polish the crank
new gasket kit
new oil/water pump
new welsh plugs


Title: Re: pistons and bearings
Post by: rickjen on November 26, 2013, 08:32:28 PM
thx, all advice taken and will do.
regards
rick
PS. If I end up solving the mystery I will let you know. Will ring up original owners son again and check out his memory he was a teenager at the time on the farm. " maybe I just solved the mystery"
teenager + new car + farm + father not looking = one wrecked motor????????


Title: Re: pistons and bearings
Post by: FCRB26 on November 26, 2013, 08:49:05 PM
Now now dont blame it on the teenager  ;D

Maybe round the clock once or twice living in the boonies and using it all the time helped it along as well...

Hmm i remember doing a smoke show in dads GQ patrol so you could be onto something.