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Cylinder head question.

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lesingepsycho

Jedi Warrior
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OK, so the engine in my car has been burning oil AND coolant and blowing a slight bit of smoke. Not so bad that I have quit driving altogether but certainly bad enough that I wouldn't want to be driving <span style="font-style: italic">behind</span> my smelly car. I've done 3 head gasket swaps with 2 different heads. It needs to be said that both heads have probably been untouched since they began life 35+ years ago.

The last time I pulled the head, I swapped it with another from the garage and I took the one that came off and had it rebuilt. It was showing some pretty major valve recession (the standard on cyls 2 & 3). But now it is all back together with new seats, valves, springs and retainers and looking good. I was planning on using it to cap off my engine rebuild project. The problem is my car is starting to smoke worse and worse all the time. I think it is due to the cylinder head that is now on there also having valve recession issues. So now my questions are:

1)What caused the valve recession? Unleaded? A/F ratio way off? Misadjusted valves?

2)What sort of risks are there in putting the rebuilt head on the old engine if I still want to use it on the fresh engine rebuild when it is complete?

You may see in another post that I just put new throttle shafts in a pair of SU's and I would like to swap the new head on with the SU's Saturday morning but I don't want to and can't afford to get the head rebuilt again before it goes on my fresh engine.

JACK
 
The original valve seats were part of the head casting. They were hardened, some deeper than others. Some can only be ground once or twice and some are hardened deep enough to be ground more times. The new valve seats should take care of that.

If your head is causing oil smoke it would almost certainly indicate worn guides.
 
How many miles do you think you'd put on the head before doing the bottom end?
 
Well Trevor, I'm guessing this new head would see no more than 1000 miles over the next year before it would get swapped out with the new motor which is being completely rebuilt as a Turbo EFI project ie. new bottom end, new everything.

Oh, I guess the other thing I am concerned about is warping. What are the chances that the block deck is warped and if so, will torquing the new head onto a warped block cause the new head to warp?

JACK
 
1000 miles is still going to be a like new head. I would suggest that there is no way you have a warped block deck.
 
tomshobby said:
Please excuse my response. I was thinking I was in the Triumph forum. :blush:
Click to expand...

It was till solid advice. .


Exhaust seats receed because of unleaded fuel, as mentioned, some of the later one had a hardning procedure done to the exhasaut seat area, but it was not so great to say the least, I think yoiu should alwys put hardened exahsut seat in a rebuilt head regardlaess of exhaust vlave recession of not, the orginal cast iron was not made to handle the hotter burning unleaded fule, so ieven if they are not recessed they still own't seal for very long after a valve job, if the hardened seat inserts are not used, #2 & exhaust are the worse due to the fact they share the same port, so it gets hotter.
 
Thanks Hap. That is pretty much what I expected but I just wanted a little confirmation.
 
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