Can someone tell me what might be wrong ? My car blew the rear head seal and all the water came out so it over heated. I have a A13 head that was cleaned,new valve seals and ready to be put on. I swapped the A12 head for the A13 head and used a A13 head gasket. I left the A12 intake and exhaust manifold. I did change the studs around so the intake could fit. I calibrated the valves and started the car. No problem, car running smooth with no smoke and charging because that what started it all,alt froze and broke the belt. Well anyway, the car is charging and running smooth, then it started tapping after awhile. I turned it off and recalibrated the engine while hot. I noticed that it was dry. I turned it back on without the valve cover and bang...NO LUBRICATION... oil is full and added some washers to the oil pump spring for more lubrication. Didn't work. My oil light turns off when started but no lubrication on top. I also took off the valve rocker arm shaft and it's all nice and clean. The correct bolt is in where the lubrication goes up !!! What can it be ? Please help. I'm getting frustrated with my car.Don't want to swap engines yet until this one is running :(

1967-1973 heads have an oil passage for the rockers. 1974-2007 head do not.



This is part of the 1974 A-series engine Re-design.

Does this mean that an A12 can't use any other heads except the one it comes with ?

You can use the newer heads but a simple modification is needed. I might add that hundreds of people have used newer heads on the A12, so it is very common.

Quote:
Read about it here: Tech: Head oil passage, especially click the link to the Discussion.

A friend had to have this done once,& while we drilled the small hole, we sure as didnot grind across the head surface. Using the original head as a guide, we drilled a hole from the side of the head that intersected both the small & the large holes, then made a small brass plug for the head, which we peened in. This duplicates the way the original head is, because there should be a brass plug in the side. This modification should be done in a drill press & shouldn't go further than the first large hole you get to. You will probably have the rocker gear seized as well, you can save this by using a fine grade of emery cloth to polish the shaft after knocking off any flashing.

I did noticed that my A13 block has that little hole sealed like the A14 and A15. Does this mean that the lubrication of these engines going threw the head is different than A12 ?

Yes. The A13 is a 1974 engine, so the rocker oiling is different from all pre-1974 engines.

Both types go up through the center head bolt. But the difference is where the drilling is for the passage that supplies oil to the head bolt hole. In the early design it is drilled in the head, in the late design it is drilled in the block.

Take a look at all those photos.

I noticed on both pics. I took off the head, marked it with the old head gasket, and drilled it on a 45 angle. I then put it all back together and now it's lubricating. Thank you all with your help on this.

Glad to hear your Coupe is back on the road.

so only drilled with a 45 deg angle? no 2 holes that intersect and a plug to stop oil running out side of head? nice, better with one hole than intersecting ones.