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Fixed One Oil Leak, Found Another!

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TulsaFred

TulsaFred

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My rebuilt 1275 has been sitting on the engine stand for about a year, never installed yet.
Cranked it up today without a problem, except, now there is an oil leak (barely any at idle, but a pretty good seep at higher rpm). Seems to be coming from the front left corner of the head gasket.
Could it be I just need to retorque the head? Or something more ominous?
Here's a pic, look at the head gasket just below the frontmost exhaust manifold bolt:

110kpah.jpg
 
Fred,
How many heat cycles have you gone thru and have you run it at, say 2000 rpm for 20 min to break it in? If you've brought it up to temp about 5 times I would retorque the head and see what that does to the leak.
Rut
 
I've had a couple that will do this. What brand and type head gasket did you use? What about head studs; did you reuse old ones, replace with new stock ones or did you upgrade to ARP? What torque spec did you use? If you got stock ones, did you make sure to get the correct 1275 ones that are rated for 50 lbs torque.
 
Prob cycled it about 4-5 times.
Seems weird though, I always associated a leaking head gasket with white smoke/water vapor and overheating. I suppose oil does traverse the head to get to the rockers and back down again.
I'll retorque it and see if it goes away.

Fred
 
Gerard, I can't remember for sure, I may have gotten one or two new studs and reused old for the rest. Prob just ordered them from VB.
I torqued them to 42 ft lbs if I remember correctly.
I used the black Payen gasket.

Fred
 
TulsaFred said:
Gerard, I can't remember for sure, I may have gotten one or two new studs and reused old for the rest. Prob just ordered them from VB.
I torqued them to 42 ft lbs if I remember correctly.
I used the black Payen gasket.

Fred
Click to expand...


OK, good head gasket. Torque for a 1275 should be 50 lbs. The correct head studs are stamped on the visible end with either a drill point or "50". Check what you.
 
42 vs 50 doesn't seem like much difference, can't the standard studs take 50 lbs?
If not, where do I source the special head studs?
 
TulsaFred said:
42 vs 50 doesn't seem like much difference, can't the standard studs take 50 lbs?
If not, where do I source the special head studs?
Click to expand...


Not sure I can answer either accurately. There's a lot of controversy regarding reusing old studs - some say they should never be reused, and since I haven't used anything but ARP fasteners for several years now, I don't know what the usual suspects are offering with regard to quality of studs and/or nuts. I know that none have any engine specific data or specs detailed on their sites. I know that with the last engine I worked that had new generic studs, a couple of them failed (stripped threads), so I replaced with ARP.

The 8 pounds could make the difference between leaking and not. It could also be a flaw in the head or head gasket. I have on very rare occasions found 1275 heads that would warp when heated up to operating temperature, and the cure was milling them hot.

If you want ARP fasteners, I can supply them for you.
 
Looks like my studs have a drill point mark, so should be good to go, other than that they are the originals and not new.
I torqued all 9 bolts to 50 lb ft.
We'll see if this does it...

s1mhpv.jpg
 
I changed the head gasket last year on the 1275 for my '69 Sprite, which was what appears to be the first time the head was off the motor. After reassembly, I found that I had to retorque the head bolts periodically until it finally settled in. Like you, I started at 42 ft pounds, but gradually made my way up to 50 with each retorque.
 
Retorqued to 50 lbs last night, reapplied a little more hylomar to the old valve cover gasket and left it overnight.

Ran the engine on the engine stand at1500-2200 rpm for about a half hour.

Definitely improved the situation. There still was a very minimal seep of oil at the same spot, but 90% better. I hope it'll stop completely after it settles in and another retorque gets done.

Should the engine be cold, hot or warm when I torque the head?
 
Thanks Gerard, next time I tighten the head I'll be sure it cold.

I do see some oil dripping from the timing chain cover now, so I'll tighten those bolts some more as well.

Gotta love an engine test stand! Makes these types of things much easier than after installed in the car.

Fred
 
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