While driving last Friday, I overheated and El Stupido Grande me didn't stop and let it cool. It blew out the head gasket and made a deep scar betweem 3 & 4 cylinders. I have to take the head to the shop and get it surfaced now. I didn't want to do that with this mostly stock A12 head. I have had nightmares with the distrubutor. I have put in every distributor that I have and they all are screwed up. When I ordered the head gasket from Advance Auto, I asked them to look up an electronic distributor just for grins. I had done this a few times in the past and they came up with "not available." This time, the 79-up were still not available but the 78-below were. I had it in hand the next day for $110 + tax. It is rebuilt but has all new insides. Hopefully this will cure my overheating problems. I will take the head to the shop today and get it back tomorrow. I'll keep ya'll informed.

Hello

I experienced the same overheating problem in my car (B310). It blew out the head gasket too. When i surfaced my engines head i raised the engine compression too.

You may be able to solve your overheating problem by doing as discussed in "Radiator Upgrade".

What is the problem with the distributor?

I hope it works...

Ric

Shame to hear about the headgasket Mareo. I just had one let go on my girlfriends '88 Corolla. But unfortunatly things got worse when it finally got to the mechanics for a fix up.

First of all, my g/f was struggling to afford the repairs and so the guy said he would try and keep the costs down. Ends up that it cost $1000 AUS. This doesnt include the cost of new coolant, oil, and re torquing the head bolts when it goes back in! Other workshops said that $1000 would cover it no worries, she didnt even mention she was hard up for cash!

Anyway, got the car back. they did all the crack testing, shaving the head, blah blah, thermostat, etc etc. My g/f drove it home the first night in slight traffic and it heated up a little more than it should. As I wasnt in the car I dont know how far it heated up but my g/f said it was about 3/4 on the gauge. Hmm, this is weird I thought. No loss of fluid or anything, all looked OK. At this point I will mention how (when the car went in)I asked the guy to make sure the thermo fans were working because I had never heard them come on anytime.

First chance I had to drive the car (two days later)I was in traffic and it was pissing down with rain. Car heated up too much so I pulled over. Popped the bonnet and there was coolant going everywhere! One of the heater hoses had gone causing all the collant to piss out and the car overheat. Got the car towed back to the workshop to get fixed as I thought it was their responsibility.

Took them about a week to replace a heater hose worth $4 and two 50c hose clamps. So another $100 later we got the car back.

Now I dont think Im an expert on cars like some mechanics think they are but I do know my fair share of things. One of those is that any decent workshop will NOT ask questions about whats wrong with the car when it brakes down until they get it back to their workshop and look it over. These guys made an assumption I was a mechanic and could track down the problem for them! (which I did, but I should have only had to tell them it lost fluid and needs towing) Then from my description of the problem they will NOT try and absolve themselves, again like these jokers did.

The mechanic said that the hose went because it was old. Fair enough, you inspect all hoses when replacing a head gasket and replace suspect ones, its a bit of a 50/50 wether you replace every single hose costing $$$.
But he couldnt tell me why the car heated up so much the first night we had it back. My theory is that the thermo fans didnt come on to cool the car down. The car got just enough flow thru driving to stop it boiling over. Then we I got caught in traffic there was no air flow, the thermo fans werent working so they didnt cool the car down and the hose went loosing all the fluid. The mechanic said that was crap. He said it over heated because the hose went. So why did it over heat that first night? The hose surely wasnt gone becasue we had no loss of fluid, not a drop. He would not stop saying that it wasnt their fault.

So we payed up and left, the only time we see that slimy prick and his workshop again ever will to be tightening the head down. Then I wont go back there again.

Just thought I would share a yarn with you guys, while on the topic of head gaskets.

Cheers,
Simon

You

Hey mario, sorry to hear about the head gasket. Luckily for us, these cars are pretty damn simple to work on. I just did a head gasket on my A-12 about 2 weeks ago, so thought I would share some stuff. Somebody here told me(can't remember who,sorry) Don't forget that one of the head bolts is different from the rest. It's the one on the distributor side in the center of the engine. It's a tad bit skinnier than the rest. It must go back in the same hole. Allows oil to flow past it or something...I don't know if you have done a head gasket on an A-12 before, but it's very simple. It took longer for me to clean the gasket surfaces than to do the actual R&R. Good luck.

i was suprised how easy it was to change the head gasket too, i knew about the diffrent bolt but last weekend when i took an a-14 block from a sunny i noticed that head bolt was in the front right (from standing in front of the car) i mentioned this to my brother in law but thought nothing of it cause i didnt know why it was diffrent, is this a bad thing? is it likely that the thread could have been damaged or do the bolts have the same diameter anyway? and will it have ruined the block in any other way, ie cause no oil somewhere? (keeping in mind the block will be rebuilt and worked before beeing used in a car again)

yes 1200, I believe all the bolts have the same thread size. I wish I could remember who gave me this info. Anyway, they told me that putting the bolt in the correct location would help to prevent blown head gaskets in the future. I believe it is skinnier to let oil flow past it, if I'm not mistaken. You know, now that I think of it, I believe it was dimlight65 that helped me out. Good luck.

You must put the long bolt in the correct hole as this is the oil supply gallery for the rockers. no lubrication = disaster. The long bolt from memory has a letter "T" stamped on it or "13". In addition I think the side (right-left) in which the bolt screwed into could be different, depending which evolution of the A-series engine you have.
It is easy to pick, as the head bolt hole threads in the block start more or less at deck height, except for the hole that the long bolt belongs, as the threads start approx 7-10mm below deck height.

As for the mechanic in tassie, sounds like he is a ruthless bastard, only interested in the dollar.

As much as I'd like to take credit for knowing where the odd headbolt goes, alas it was not I who helped out. I'm just as in the dark about them as everyone else.
I don't mean to cast doubt in the minds of others but, are we sure it is the A-12 that has the odd bolt? It seems like the ARP head stud kit that I bought for an A-12 had all of the studs the same. Also, while comparing heads at the machine shop the other day, the A-12 seems to have an oiling hole where the A-14 does not.
I wonder if Gil's A-14 has the "oiling bolt" in the wrong hole and that is why he is eating the #4 intake pushrod. I need to look that engine over again.
Incidentally, I did not build that engine! It wasn't my screw up if that is the case!

Hi Ya'll,

Sorry to be gone all week but I've been very busy. Thanks for all the info and stories on head gaskets. It would not have blown if I had taken the time to deal with the first wounds and slowed down a bit to keep it from overheating.

The center bolt closest to the distrubutor is the longest bolt on the A-series heads. I didn't know about it being part of the lubrication system, thanks for that info.

The head war scarred between #3 & 4 cylinders so I had to take it to a head shop and have it milled a bit. While I was there, I saw an A-block head on the shelf so I pulled it down and looked at it. It was an A12 high compression head with the heart shaped coubustion chamber. It was new and had never been bolted on a block yet. He said that it had been there since the 70s. I paid him $75 for it. The head that was on the A14 motor was a sort-of stock A12 head so I just put on the new HP head. It has the round ports. I spent two days with carbon router tips and sanding wheels just a porting away. I didn't take off anything metal that was needed but I smoothed the ports real well and made all of them the size of the manifold gasket port openings. I deburred everything in the chambers but left them alone pretty much.

I put the new distributor on it also and it wouldn't fire. I took it back to Advance Auto Parts and a new one should be there in the morning. So that means that I haven't been able to drive for a week now.

How could a distributor make a motor overheat?

With the Datsun distributors, they have a little triangular piece of plastic that holds three little ball bearings in place that the rotation spark advance plate sits on so the timing can advance when needed. This plastic gets old and cracks, letting the ball bearings come out of place and making the spark advance plate ride crooked. The spark is weakened as a results and the motor runs like it is in a rich fuel condition, which in turn, makes the engine overheat. El Stupido Grande, that's me, didn't stop and let the engine cool down causing severe overheating and the blowing of the head gasket.

Hopefully, tomorrow, Mareo Speedwagon SIX will be riding again.

Mareo