Can this be repaired?

Al Weyman · 18 Apr 2008, 08:41 (Ref:2180460)

This is what has given me so much grief this last week or so and has caused a new engine to promptly fill with water in minutes of start up (and yes I know I should have pressurised the system before firing up but I did'nt!).

Small hole in iron cast SB Chevy head where spring platforms had been enlarged. They are brilliant heads apart from that and have ahad a fortune spent on them and I really would like to save them as I have also matched a new Victor inlet manifold to them.

terence · 18 Apr 2008, 08:51 (Ref:2180468)

Plain and simple? Yes,no reason that cannot be welded/brazed Al.

275 GTB-4 · 18 Apr 2008, 10:05 (Ref:2180508)

Quote:

Originally Posted by terence bower

Plain and simple? Yes,no reason that cannot be welded/brazed Al.

Tap it and whack a bolt or grob screw in there???

MechaniX_034 · 18 Apr 2008, 10:32 (Ref:2180527)

I don't know how accurate this is(my experience is limited to repair and reco) but you may have to contact the head manufacturer and ask if its a primary water pathway you're now having to deal with. In either scenario, and especially if there's a grub screw at either end you can have it welded and the pathway repaired as well as having the seat refaced. Pretty costly though, but its better than throwing the head out since you've already matched to it.

In the worst case scenario, you may end up needing to cap it with a grub screw after the repair is finished. All this depends on if there's enough material to pull it off.

GORDON STREETER · 18 Apr 2008, 12:37 (Ref:2180634)

Clean it out with a small dremel type tool and repair it with a two pack metal repair paste. Welding or brazing may cause more problems unless its done properly as cast iron is one of the worst metals to do.
I have used this on many occasions successfully, and once run a head for two seasons after being over enthusiastic with the cutting tools in an inlet port !
As long as the area hasn't got actual flame heat like a combustion chamber or an exhaust port it will work fine. You have nothing to loose, and to be sure have the head pressure tested at your local engine recon shop after you have done it.

banger_racer · 18 Apr 2008, 12:47 (Ref:2180644)

Totally agree Gordon chemical metals the way to go.

Al Weyman · 18 Apr 2008, 13:10 (Ref:2180660)

SOmething like that JJ weld stuff Gordon? It will be in a cold area as it goes into the water jacket not the chamber. I can pressure test it on the bench by doing a dummy build and hooking up a rad which is what did with this one as I thought I had lunched the block originally.

GORDON STREETER · 18 Apr 2008, 13:16 (Ref:2180662)

Al you may think doing this is a bodge job but believe me it works. A lot of the
road head gasket jobs I do would normally involve loads of work like welding and then machining, especially on aluminium heads that corrode away if using the wrong type of coolant. If I had to have that done every time the bill would be pretty high and most of the time wouldn't be cost effective.
I have repaired all sorts of heads this way including a cossie OK it cant perform miracles but used properly you would be surprised what it will do. I know a well known Mini racing driver (no names) that run a season with a rear subframe mount held in by this method !!!!

The plastic padding type of stuff but chemical metal,

terence · 18 Apr 2008, 14:48 (Ref:2180721)

I'll go along with that Gordon,JB Weld is very good although a TIG Braze would not cause any further damage and is easy to machine back if required.

NiG_21 · 18 Apr 2008, 14:54 (Ref:2180725)

I can put you in touch with a cast iron welding specialist who welded my head last year if your interested.

Cost about £150 - repaired two cracks in the combustin chamber and re-tapped the plug holes for me.

Send me a PM if you're interested - they are in Coventry but I posted my head up there for about £15.

**Tim Falce** · 18 Apr 2008, 14:58 (Ref:2180728)

I would go for a bolt or plug that fits snugly and JB it in.
I had a large plug that screws into the top of one of my Jag heads strip the thread. I put it back in with JB weld or something similar and it has been fine since, that was 5 years ago.

GORDON STREETER · 18 Apr 2008, 16:22 (Ref:2180786)

Quote:

Originally Posted by falcemob

I would go for a bolt or plug that fits snugly and JB it in.
.

Tim I think Al is talking about the spring platform that has been machined through. So I don't understand as regards the above ? If you take another look you will see.

**Tim Falce** · 18 Apr 2008, 16:28 (Ref:2180791)

Quote:

Originally Posted by GORDON STREETER

Tim I think Al is talking about the spring platform that has been machined through. So I don't understand as regards the above ?

Aha, I've put my glasses on and looked at the picture properly. I thought he meant the hole to the right, I did wonder why he would want to plug that one up.

Note to self, never post in Race tech again as I don't have a clue.

GORDON STREETER · 18 Apr 2008, 16:32 (Ref:2180795)

You are forgiven

Robyn Slater · 18 Apr 2008, 17:22 (Ref:2180820)

You could try metal stitching.
I,ve had frost cracked blocks repaired by this method.

Got a mans number if you need it.

Robyn

Al Weyman · 18 Apr 2008, 19:13 (Ref:2180916)

No I need that hole Time, it takes a bolt that helps hold the head down! :-)

bdwoody · 18 Apr 2008, 20:01 (Ref:2180938)

having now seen the picture al that could defo be welded up with a dissimilar rod or tig braze .jb would also work but you have got to prep it properly or its gonna fail again and that would be a pain.on the bodgey side of things i have welded up a pinto water pump once with a mig welder we it started to leak out of the giggle hole it was supposed to be a temp job but lasted about a year!!!!

**dtype38** · 19 Apr 2008, 06:56 (Ref:2181154)

FWIW, if it was mine I'd drill the hole out circular, tap it, JB weld a grub screw into it so that it was sticking out on this side, then when its set cut the grub screw back to the shape of the spring seat with a small carbide cutter in a dremmel or die grinder.

Do let us know which way you pick :-)

GORDON STREETER · 19 Apr 2008, 11:39 (Ref:2181308)

IMHO I would have thought looking at it that its only fag paper thin. so drilling it bigger would only make it worse !
Al does the spring seat "have" to be that diameter?

zac510 · 19 Apr 2008, 14:03 (Ref:2181400)

Yikes, who did the machining job for you?

Al Weyman · 19 Apr 2008, 14:44 (Ref:2181421)

Yes the seat has to be that big to accomadate the roller cam springs Gordon, the heads are off an F5000 car and I believe the work was done stateside there is a stamped name on them but I cannot remember what it says the rest is such a nice pucker job and its probably just bad luck thatt he casting was thin there. The guy who sold them too me has offered to refund me or pay for the repair which seeing as I bought them a while ago is pretty decent.

Eric Falce · 19 Apr 2008, 17:32 (Ref:2181483)

Devcon,thats the name of the stuff I have been trying to think of,used to use it to repair all sorts of castings back in the good old days.It takes at least 24 hours to set,but then you can grind or machine it,but being a lazy sod I would clean the head,heat it a little and glue the valve spring seat into place with it,the valve spring will hold it in place to set.You can buy some other stuff from Tiplers in the Old Kent Road that is added to the water and seals everything in the water system.Just another few thoughts Al,good luck.

**dtype38** · 19 Apr 2008, 21:31 (Ref:2181574)

Quote:

Originally Posted by GORDON STREETER

IMHO I would have thought looking at it that its only fag paper thin. so drilling it bigger would only make it worse !
Al does the spring seat "have" to be that diameter?

Don't understand that Gordon. The casting is obviously thicker immediately adjacent to the hole (where the seat isn't cut). My only assumption is it gets thicker towards the valve guide stem, which would seem reasonable if the valve spring is going to have anything to push on. So the bigger it's drilled the thicker it gets... no?

ian.stewart · 20 Apr 2008, 15:39 (Ref:2182189)

Mmmm, I keep looking at that, tyring to think of a better way to seal it,
Possibly, this may work, deepen the spring pocket and enlarge the spring seat area, a bucket can be made to cover the area of the new seat and cover the the damage, and bring the seat area back to spec, then if the machining is up to spec you may get away with a good sealer, or if you are still worried about it mig braze the cup in position,
Ian

**dtype38** · 20 Apr 2008, 16:37 (Ref:2182217)

Quote:

Originally Posted by Al Weyman

The guy who sold them too me has offered to refund me or pay for the repair which seeing as I bought them a while ago is pretty decent.

That's so nice to hear Al. Really cheers everyone up to know that there are such good suppliers/sellers still around. Also means that you can now just take the head to your favourite "head" man and get a quote for a professional fix without needing to second guess how to do it.