Rb26 Snapped Cam!

[Midnight_Blue_32]

I few months ago I had a bit of trouble with my 32r when It died on me while I was having a bit of spirited drive, after giving it a quick look over trying to sort out the problem I had noticed that the cam key for the cas had snapped so at the time I figured ill leave it sit for a while so I work on my other cars. So tonight I started to get stuck into it and discovered that the real problem was that I had snapped my exhaust cam which has caused damage to the front 2 cam caps. I'm just wondering what else could've been damaged in the process ie valves or even pistons? And is it possible to get the damage to head repaired or would I be better off just replacing the whole head since I plan on having the engine out in the next few weeks anyway. I've added a pic of the cam but I forgot to get a shot of the head damage but i should have one tomorrow.

[Frosty]

wow! nice work!

its likely that there will be damage to the valves/combustion chambers but really depends on the situation! was it hard revving or anything when it happened?

[Midnight_Blue_32]

Not really from what I can remember I was done getting up it and I was only just getting back up to speed. When it happened I thought I'd popped a cooler pipe off.

[luke gtr]

this happened to another member here, but was rear of intake cam.

turns out, threads stripped from the cam cap bolt holes.

if youre pulling it out, pull it off, get helicoiled, cleaned and tested.

should be fine.

the valves would have stayed closed, so should be fine.

[GTScotT]

Valves CAN be damaged, you need to test.

The cam would come to rest at a neutral position but there is no telling where it was pointed when it snapped. So it is possible that the cam was not yet in a neutral position when it snapped and a piston caught a valve on the way back up.

Compression testing should give you an indication if there is any damage. Comp test by pumping air into the cylinder when it is closed, not by doing the normal crank test.. You would do that after you replace the cam and have it all back together.

[Midnight_Blue_32]

I dont know if it would be worth getting repaired because I've found complete heads from 600-1500, so it'd probably be just cheaper to replace it. But it Looks like ill be pulling it out next week and inspecting the damage and going from there, I just hope the pistons aren't damage because I did a forged rebuild on the bottom end about 10000 Kms ago.

[Ben C34]

Do the comp test by pumping air in with the cam out. That way all of the exhaust valves should be shut and will let you know of any bent valves. It is extremely likely the are vent valves, no point putting can back in just to find that.

[Adriano]

or for a really fast test, when you remove the cam, put straight ege across the cam followers, a bent valve will show up as increased clearance

[Stock e-Tune]

From the look of that bearing next to the breakage,

looks like it had some contamination go through it and made it very hard to turn.

I would not be just getting the head checked for this one. Drain the oil and look for contaminants

anything suspect, crank must come out, oil pump off. see what else is damaged I'm afraid.

be easier in the long run..

I have a set of HKS drop in cams here if not using this as an excuse to go full house (cough cough like I did).

btw, removing a set of cams involves a little more than just undoing the caps. must be released evenly not to damage the front bearing inner flange face. Much easier if you have a dial indicator gauge at each end.

Edited July 12, 2013 by Stock e-Tune