I am in the process of screwing together an engine (Holden grey motor, 1948-1963, 138ci taken out to 155ci). Aim is to install it into my FED build - blown, injecting, and running alky. The head on this thing is something special - a Repco aftermarket crossflow head. The only made around 200 of them, and most were busted in roundy round or hydroplanes in the 60's. It's worth around $US14,000, so I am being somewhat careful as I rebuild it. The heads are reknowned for being either porous or cracking. This one leaked water, and was "Loc***e'd" back in the 80's. I ***ume this is done using this product: https://www.eis.co.za/index.php?route=product/product&product_id=3151 Not sure if Loc***e even make it anymore, but will contact them too. Anyhoo, I really need to clean the head up. Needs the paint off it, muck out of the water p***ages, and grime off. I would normally give it to a machine shop to do, but am wary of stuffing it in the process. I ***ume the Loc***e is some form of epoxy, and impervious to fuel and warm water. Not sure how it would handle caustic or acid if the machine shop decided to clean that way. Anyone had any experience refreshing a Loc***e'd head please? Cheers, Harv
Kinda sorta on the topic, I bought a Rajo overhead model T head years ago that had been welded in one combustion chamber. Being an expensive head, I wanted to fix it rite. I brought it to Crow Cast Welding near me to be fixed proper. Its a spray welding technique, and he is very good at it. Point is, he said if it works, dont fix it. Mine was pressure tested, he could have charged me a lot of money to mill out the old weld and redo it, but suggested no, leave it alone. It had been run with the old repair. So, if your's is not leaking, why not use a more gentle means of cleaning and run it as is? Not a big job to remove a head if it leaks and move on to a better repair from there
Loc***e 40D still shows as an active part number, but not in the US or Europe. There must be something in it that is not acceptable in either location. If it does what it says it does, and is a one-part epoxy, there must be some nasty stuff in it. I would manually clean the head. It's less risky.
Have you contacted Loc***e about a solution? Maybe they know the secret, if there if there is one, for safety removing their product.
Where has it been Loc***ed? In a critical area or in the water jacket. Are you going to run coolant or epoxy the block with just the head with coolant?Can the Loc***e be ground out and replaced with JB weld or similar?
I’d like to see a pic of where it (the sealant) was used myself. Not that I’d be able to offer a suggestion, but just curious!
Since Loc***e makes a number of different locking compounds, and the release method varies between them, I would check with them on your specific one. However all of the various series have a method of removal. The options go from heat up to chemicals. Some of the chemicals can be a bit nasty, but some series can be softened with WD40.
I'd start by trying a small area using acetone on a rag to see how it works. I've had good luck softening Loc***e with acetone, and then use a razor blade to remove it before it re-hardens. Have to work with small areas as the acetone dries too quickly to do much before it hardens again.
Hi Harv...... Since you mention that they are prone to cracking, was that when they were normally aspirated or when boosted as you plan to do?
Thanks everyone for your feedback. I've contacted Loc***e, but have not had them return the query yet. My understanding of the process is that it is not a paste that is glooped onto a crack. I think the product is a liquid that the head is soaked in. Maybe it gets soaked in a tub, maybe you feed the Loc***e into the coolant system. In any case, there are no areas of the head to send you a picture of with the gloopy stuff. This might have to suffice: I really don't want to release the Loc***e... I want it to remain in place despite my efforts at cleaning the head. I'm worried that if I use something like caustic or acid (say oxalic acid) that the Loc***e will come out of the cracks/pores and I won't know until I run the engine. AFAIK, they all cracked naturally aspirated. I'm not aware of anyone having supercharged a Repco head before. I don't know of anyone who has campaigned one at a drag strip either... they were mainly used in speedway, road circuit cars and boats. Plan at this stage is to clean the head in petrol to get the oil off it, and use a wire wheel to pull the paint off. Flush the water p***age with water and call it a day. To give some idea of scale, the standard (non-crossflow) headed engine puts out about 75bhp. With some serious port, polish and cam work they can make around 130bhp. The Repco heads were doing 180bhp back in the 60's. I know of one gentleman who is getting about 210bhp out of one naturally aspirated (albeit EFI'd). I'm running mechanical injection, and around 10-15psi of boost via a period vane blower. I need about 220bhp to break 10.99 seconds in the FED. That will allow me to run in the Modified cl*** at the track. I know of only one other grey motor that has ever run that fast (naturally aspirated, standard type head, in a rail, back in the 80's) and can't work out how he did it. This FED project is teaching me a lot, but I suspect I will have many years of fit-and-fiddle until I can get it reliably competing in Modified. I do have a cunning plan though to line the FED up against a HAMBSTR... just need to find the right event for Spanners and I to attend Cheers, Harv
Okay, so your question wasn’t how to remove the loc***e, but how to clean the head and not disturb it? I think most (like myself) thought you wanted to get it off and start again.
Is it an actual Loc***e product or was that just the process? Way back I used to seal up heads at NAPA with straight KW block seal. Would circulated it though heads heated for a few hours then pressure test. I would guess for insurance you could re seal. Set up a small pump and heated tank, plug all the p***ages and run it through one end and out the other. If you heat it to above running temp should seal it. Could double check by using the same set up and pressure testing @ 20# with a bit of soap. Maybe even do that at heated temp to verify something isnt leaking when hot. BTW. Henkel is the parent company of Loc***e. Same people that make Bonderite Alodine.
I used a loc***e process for sealing aluminum die castings for avionics. In the 80's. There was a vacuum chamber with a vat of loc***e liquid inside. The parts were submerged and a vacuum pulled, which ****ed the air out of all the porosity. Then when the vacuum was vented, the liquid would penetrate all the pores. It was a very effective process and you really could not get the loc***e out afterward. We tried, with no luck for weld repairs. Certainly soap and water won't hurt the loc***e. If Repco did the sealing (likely) a similar process was probably used. IF it looks like a non-factory repair, you never know. I would clean the **** out of it and find someone to do a vacuum penetrant reseal.
Hopefully Harv that day will come. I'm planning to run at Sydney in June for the postponed Day of Drags. A couple of the Queensland blokes may be coming down for it including the Grey Ghost.
Not sure if Loc***e/Henkel did the "Loc***ing" or a small company. From the sounds of it, it was a hot tub/circulate kind of method, perhaps vacuum instead of circulate. I'll mechanically clean it, and call it good for now. I've entered the Day of the Drags with the wagon (for once I am home... but need to fly out the next day ). Be good to catch up... been a long time. Look forward to finally meeting Brendon too. Cheers, Harv
We used the vacuum evacuation process on aluminum front covers. At first it was to salvage marginal prototype castings, but eventually it became a production process. Pretty sure Loc***e was the material vendor, but it’s been a long time. I know we tried it with iron heads, with mixed results.
Feedback from Loc***e is that the head was likely commercially "porosity sealed" using Loc***e Resinol RTC. It is an anaerobic sealant that has varying resistance to different chemicals. Mechanical cleaning will not affect it, and cleaning the scale out of the water jacket with oxalic acid solution will not be a problem. It can handle room temperature caustic, but running in a hot tank at pH 12 and just under a slow simmer for a few hours may be a drama. So wire wheeling it planned to get the paint off, and some petrol and nailbrush/toothbrush to clean up any oil. Cheers, Harv
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