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Cracked block question RV8 3.9...
Posted: Thu Jul 07, 2011 10:07 pm
by Blackflag533
Evening all,
Just filled up the cooling system on the car to find all the hose joints nice & tight, but an unhealthy flow of water out a crack between the two core plugs on the right hand side of the block.
Silly question time: is ally welding an option or am I digging the 3.5 out and putting that in instead...?
Thanks in advance.
Posted: Thu Jul 07, 2011 11:29 pm
by davemgb
Alloy welding is probably more of an option than a similar repair on an iron block but if there is a crack externally then what chance of other defects in the block casting?
Is the crack between the forward or aft pair?
Dave
Posted: Fri Jul 08, 2011 7:47 am
by DaveEFI
It's a strange place to crack? Any chance it froze up in the last hard winter?
I'd be inclined to try JB Weld. Not much lost if it doesn't work.
Posted: Fri Jul 08, 2011 8:01 am
by Blackflag533
Cracked horizontally between the forward pair.
The car sat inside without any coolant in it over the winter but there would have been something remaining in the block.
Posted: Sun Jul 10, 2011 7:10 am
by unstable load
Strip it down, have it chemically cleaned and then give it a good look over for internal damage, maybe even a dye penetrant check. If it looks good, clean out the crack and JBWeld it from inside and out and you should be good to go.
Posted: Sun Jul 10, 2011 7:49 am
by JSF55
I've had one cracked block repaired by welding, this was between the rear pair and that was fine, i had a similar smaller crack on my last 3.5 and added kalimex. Worked the rest of the engines life including be thrashed up the strip and saves pulling the engine out !
http://www.kalimex.co.uk/index.html
Posted: Sun Jul 10, 2011 6:34 pm
by bigaldart
We fixed one of the rear wings back on the block after the flywheel spacer let go and blew it off. Cut a piece from a scrap block and glued it in place using perforated metal and Belzona. Belzona is expensive but will do a great job as long as you clean everything thoroughly. I would have no qualms about welding either if I had the facilities.
Alan
Posted: Tue Jul 12, 2011 12:24 pm
by Blackflag533
Thanks for the replies all.
I'm going to clean it up and use some sort of two part to seal the crack.
And, i'll let you know how it holds (or not)