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Re: Blown Head Gasket!

A proper head gasket shouldn't need "extra" torque. A FelPro or Payen should be fine with the increased compression. Shoot HiTack on it and wind it down. I've used plenty of flat top pistons in MGB engines with no cronic problem. You have done the "usual" stuff like check the head/block to insure they're "true" I imagine.

You've a set of 40mm Webers on it, too, right? If the thing is running lean at RPM it can cause some head gasket grief. Usually tho, that holes a piston. UGH!
 
Re: Blown Head Gasket!

Bugeye58 said:
Basil, my suggestion would be to switch to ARP head studs, and follow their torque recommendations. You can get the stud kits from APT. P/N HST425-10.

https://www.aptfast.com

I ran ARP studs and a stock head gasket on the race 1500, at 13.8:1 compression, and never poofed a gasket.

If you had re-used the old studs, there is a good chance they had been stretched beyond their elastic limit at some point, and weren't giving sufficient clamping force.
Also, make sure the block and head surfaces are flat.
Jeff
Click to expand...

Thanks Jeff...and thanks for the link! I could spend lots of money there I think! I will definitely get new studs/nuts. I have no idea how many times the current set have been torques and re-torqued. I'm going to take the bloack to my local machine shop (with head) and make sure both are flat! On a related subject, what do you think of roller rockers over the stock rockers? (and also valve springs - replace with uprated set?)
 
Re: Blown Head Gasket!

DrEntropy said:
You have done the "usual" stuff like check the head/block to insure they're "true" I imagine.

You've a set of 40mm Webers on it, too, right? If the thing is running lean at RPM it can cause some head gasket grief. Usually tho, that holes a piston. UGH!
Click to expand...

The engine was rebuild by a shop in Illinois (don't even remember their name). No idea if they insured anything. This time, I plan to make certain head and block are true! Tell me more about HiTack...what is it where can I get it...are there any down sides?

On the question of the webbers, if anything they are running rich. That will be another thing I do is to try and make sure I have the best set up as far as jets, etc for those webber giving my engine set up. altitude, etc. This is gonna get fun.


Basil
 
Re: Blown Head Gasket!

I think that Doc means Permatex High Tack in a spray can? Is that it Doc?

Basil, either install or get hooked up to and air fuel ratio meter to complete your carb/tuning adjustments. It makes life a LOT easier.
 
Re: Blown Head Gasket!

Yep, Paul. High Tack is a Permatex product, aerosol can, STICKY. Made for the head gasket application. Down-side is a bit more effort at cleanup on the next head removal. No biggie.

I ~assumed~ you'd put the thing together, and further that the head studs had been fresh... my bad.

Go with Jeffrey's suggestion of ARP fasteners, fer sure. Checking head/block for "flatness" ~should have~ been a routine part of a rebuild, BUT: if the builder was "uninspired" in any way you could have been given a less-than proper job. I've seen too much of that in past: "It's just a stoopid li'l ferrin four-banger. Screw it together, it'll run past the 90 days. Easy money."

BAH.

Not to disparage the particular shop, but it has been more often than not a situation I've run into.
 
Re: Blown Head Gasket!

Hi Basil,
I’ll second the ARP recommendation (or is that third by now?). They are local to me, so I’ve stopped by on a couple occasions. Really nice people. One note: they have two different torque specs depending on what type of lube you use to assemble the parts. Their moly lube will have one spec and 30wt oil will be another, higher figure. See their catalog on page 24.
 
Re: Blown Head Gasket!

Basil,

Make sure your biceps are in good shape. Part of the required ARP assembly process is a five (5) time retorque of the studs.

One you start, be prepared to finish. But they are worth it.

You can see them towards the end of this page of my site:

https://www.74tr6.com/cylinderhead.htm
 
Re: Blown Head Gasket!

Basil, I'm a fan of roller rockers, but they are way overkill for most street applications. There are a couple of racing classes that require the use of stock rockers on the Spit, and I haven't seen any problems with them.
When you did the cam swap, was it just a cam change, or a complete kit, i.e., cam, lifters, springs, etc? If it was only the cam, and it was a Kent, APT can supply you with the proper spring recommendations.
Pay close attention to the cam lobe and lifter faces, as there were some bad lifters out there. I wiped a brand new cam because of that. I got it all fixed, but it was a major hassle, two days before a race weekend. Again, APT has the best lifters out there. I don't mean to sound like a shill for APT, but I've dealt with them for many, many, years, and have always received nothing but quality from David and the gang.
I'm quite familiar with the 1500, particularly at the performance end, so feel free to pick my meager brain cells.
Jeff
 
Re: Blown Head Gasket!

Bugeye58 said:
so feel free to pick my meager brain cells.
Jeff
Click to expand...

THere will be a whole lot of lickin' going on! I want to get this thing rightas possible the first time. To be honest, I don't recall if the cam was just the cam or the whole kit so it probably would not hurt to do new lifters, springs, etc.

By the way, I only remember that the cam I bought was a Kent cam and I 'think' it was "mild street" - but how can I determine that for sure and determine what the lift and duration are so I know for sure what I'm dealing with?
 
Re: Blown Head Gasket!

There should be a number on the front of the cam, such as 266, or 276, for example. If you can find that, I can ID the thing for you.
If you can't find it, it's dial indicator and degree wheel time.
Jeff
 
Re: Blown Head Gasket!

Bugeye58 said:
There should be a number on the front of the cam, such as 266, or 276, for example. If you can find that, I can ID the thing for you.
If you can't find it, it's dial indicator and degree wheel time.
Jeff
Click to expand...

I was going to work on it yesterday but was just too danged cold (we're having ice/sleet snow since yesterday). But I'll chek for that number as soon as I get the cam out, which should be soon.
 
Re: Blown Head Gasket!

I feel your pain on the weather, Basil. It's been
raining here like the dickens. Waterlogged.

But, then, you'd proabably laugh at rain.

Gotta share: Tourists visit San Francisco from far
colder climates than California. 45 degress, we
put on long-johns and a warm jacket.

They put on a pair of shorts and talk about how nice
and warm the weather is in California.....all the
while standing by the Bay, no less.

All in what you're used to, I suppose.
 
Re: Blown Head Gasket!

I walked the length and breadth of SanFran in May one year... I thought it COLD. Other tourists were doin' just what Denny said: shorts 'n T-shirts (or Hawiian ones), gawkin' at the rest of us bundl'd up like Nanook. <shrug>
 
Re: Blown Head Gasket!

Mark Twain said "The coldest winter I ever spent was a summer in San Francisco."
It gets downright nippy around the Bay.
Jeff
 
Re: Blown Head Gasket!

Bugeye58 said:
There should be a number on the front of the cam, such as 266, or 276, for example. If you can find that, I can ID the thing for you.
If you can't find it, it's dial indicator and degree wheel time.
Jeff
Click to expand...

Well, I have the motor completely torn down except for the Crank which is still in. Jeff, the number scribed on the front of the cam is "OC 729" Does that tell you any thing?
 
Re: Blown Head Gasket!

Well, I will be taking my motor to a local shop that was recommended by a local Healey guy. Going to have a sleeve put on back of crank to see if that will finally stop my rear seal leak. While I have it all apart I am going to get a quote on having the head polished and ported as well.

Basil
 
Re: Blown Head Gasket!

Sorry about the delay, Boss, but work keeps getting in the way of everything!!
OC 729 doesn't mean anything to me, but I'll bet if you called APT they could figure it out.
I'll do a bit of research on this end, as well. (In my copious free time!)
Jeff
 
Re: Blown Head Gasket!

Bugeye58 said:
Sorry about the delay, Boss, but work keeps getting in the way of everything!!
OC 729 doesn't mean anything to me, but I'll bet if you called APT they could figure it out.
I'll do a bit of research on this end, as well. (In my copious free time!)
Jeff
Click to expand...

I tried Google but cam e up empty. Since I'm going to buy new head studs from them, I guess it would be fair to ask them about the cam - maybe that number will mean something to them. LIke I said, I "think" it was a Kent mild street came, but it was so long ago that I bought it I don't remember for certain. I just know it was not a race cam.

PS: I think I have decided also that I'm going to drop doen to a single Weber carb. (DCOE 40). My set up now is two of theose, which I am convinced is over kill.


Basil
 
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