Potential cylinder head damage from oil starvation.

[Diomedes]

Once more I have come to lap at the font of knowledge 🙇‍♂️

 

So, continuing to trawl most corners of the net in search of parts to build a complete RB26/30 from relative scratch. Have found a used cylinder head that has come off a 93 GTR.

Seller was upfront about history, which is always a good sign. Head came from a mates car, which was a tuned low mount double jobby putting out around 400hp? He was not sure on power. Engine suffered some sort of failure, but lost oil pressure. Said he took the head to have it looked at, and the guy (from head to head in clayton if that helps) said it needed work but could be saved. I'm going to get into contact with the repair shop who hopefully remembers the head in question. But otherwise will pay to have it looked at by a shop to get another appraisal of the head before paying for it, especially since its in Melbourne and I'm in Perth.

Now, I'm no mechanic but if the engine is starved of oil the parts that rub together get a bit sad. So I'm guessing the camshafts, the camshaft caps and the journals will need some machine work? Buttttttt, If I don't plan on using the OEM camshafts and plan to go for an aftermarket set, I would need to get the camshaft housings line bored anyhow? So it might not be that big of a deal? What are some of the other problems a cylinder head might suffer if it has run out of oil? 🤔

 

Included are photos for refrence.

 

Cheers

[GTSBoy]

Imposssible to say fro those photos. I would trust the "could be saved" assessment from before, as it is difficult to completely f**k one.

[Diomedes]

Yeah, I'm gonna hit him up for some closeup photos of the journals/caps.

Its at a decent price, especially since it has all the required parts for a complete cylinder head, minus the passenger rocker cover 🙃

I thought the same regarding the head not having oil. Its a camshaft, not a crankshaft? Surely the forces would be small enough that they couldn't do that much damage...

[Duncan]

You really need to know the machine shop's quote to fix it if you are going that way.

The head is easy to hurt more than the block from an oil issue because the cams are steel, running in an aluminium head, withhout bearings in between...it can get chewed up pretty quick.

[Ben C34]

Fitting cams you never need to machine the cam tunnel, so don't talk yourself into thinking that is a cost you have to pay regardless. The machining for cams os clearance for the lobes, the tunnels are untouched.

 

 

Fixing f**ked cam tunnels will cost a lot. Get a quote for that.

[r32-25t]

I wouldn’t go near it, there’s a reason he’s left the cams in, the 3rd journal on the intake cam is stuffed and the 1st, 2nd journal on the exhaust are pretty bad and the 3rd and 4th aren’t far behind them 

[Dasmbo]

Im sure the head can be repaired but it not just a simple close and hone of the journals and caps the head will have to be stripped alloy journal areas will have to be welded and built up then if all goes well will have to be machined new caps cams guides possible valves lifter buckets it wont be a cheap job i hope for your sake you have very deep pockets. I would be looking for another head i think it would be much cheaper try Lewis engines see what they might have or can do for you they did my head and it wasnt damaged like the one your looking at and my head cost me over $5000.00 seven years ago 

[Diomedes]

Resolution to the question.

While still waiting for those closer photos of the journals/caps, I got into contact with the guy from the repair shop, and he outlined pretty much what Brett/R32-25t said, though in a very diplomatic manner 😅 Head is not worth the money seller wants, maybe only worth as a very cheap experiment to someone with the means and the time to try something crazy on.

A bit more to the story, but another case of making sure people should do their homework before buying anything second hand, and again making me very grateful this site exists.

 

Edited January 21, 2022 by Diomedes

[Diomedes]

That is correct Dasmbo, the machine shop that examined it said few journals would have to be welded and built up, then machined back. The damage had the machinist questioning the integrity of a few of the cam cap retaining bolt locations...

Basically said if it was a Ferrari, sure, the money and time would be worth it. Not for an RB26 head.