engine and drivetrain Bad Headgasket, Bad Times

[tsareuitar]

Hey all, 

 

Looking to talk shop with somebody.  I blew my radiator a few weeks ago and my 76 overheated pretty bad in the process.  Replaced the radiator and everything seemed fine on the initial testing run, but things quickly went down hill the next day.  Car gradually lost most power and started smoking a little (well, more than usual).  A compression check shows I have no compression on cylinders 1 and 2.  Bummer

 

Looking for advice:  the cheapest/easiest option is probably just to buy a known-good or freshly rebuilt head off somebody on the forums or down at Double02Salvage or Autohause909 (since they are in my area).  Otherwise, I'd have to pull the head, get it down to a machine shop to see if its warped beyond repair, and then have somebody take it apart and rebuild, ultimately costing more time/money.  I guess I need to figure out what head / compression I'm running right now, but since I'm a 76, I'm assuming its an E21.  Is there any way to figure out if you have flat or domed pistons without pulling the head off?     

 

Lastly, its always been a fantasy to move to a longer cam with the ultimate goal to have this as a weekend car / autocross car.  I figure since I've got to take the damn thing apart anyways, I might as well swap a 292 in there.  I've been very slowly building that way with a Weber38 (jetted to something that works on a fairly stock setup), cannon Intake, Tii exhaust manifold.  Any suggestions on this?  Would I see real world power results without replacing the stock pistons?  I'm quickly getting to the end of my backyard mechanic experience.  Am I on the right track here?  What would you do?  

 

Thanks for all the years of mostly good advice!

 

[KFunk]

Keep in mind, if you're wanting an autocross car, then switching cams (or pretty much anything else inside head/engine), will bump you into no man's land in terms of classes (EP at minimum, I believe).  That doesn't mean you won't have fun autocrossing it, but if anyone is fairly competitive in your region, then you won't be competitive.  I've had my fill of autocrossing regularly in FSP, and just decided to have a fun engine for occasional autocross usage, where I only get trophies in EP if nobody shows up.

You can also lie, and hope no one figures it out.  But if you start beating them regularly, then they won't be happy, and you'll be a bad person. 

[FB73tii]

The head type is stamped on the driver side of the head toward the rear. Since the head is coming off anyway you'll see what pistons you have. There is a good chance the head can be saved just by skimming a bit off, don't write it off until your machine shop inspects it. If the head is in good shape (valves and guides) you really don't need to fully rebuild it. If you put in a bigger cam you need higher compression (than stock) pistons to get any real performance out of it, at least 9.5:1. Sounds like you need to decide between a quick fix and a full rebuild with pistons, cam, rockers, etc. Hope you have a trusted shop, a poor mechanic will do a "lift and slip" and just replace the head gasket without inspecting anything. Those typically fail fairly soon.

 

Fred '69 & '74tii

[Buckeye]

If your car is 76 and if it is original engine, then you have E21 2.0 cylinder head. You can confirm it with looking at cylinder head (intake side) near firewall. Suggest that you take head off and let the shop check straightness and also pressure test. Then after findings decided what needs to be next. For machine shop to check flatness and pressure test shouldn't be > $80

GOOD LUCK!

[Cru Jones]

Since you're in CA and you have a '76 you might want to be careful with a bigger cam as you'll quickly run into issues passing SMOG. Surprised you pass SMOG already with a Weber 38/Cannon intake/tii manifold.

[tsareuitar]

Thanks guys, you brought up some great points!  I'll chew on it for a few days here and let you know how it ends up