Head Gaskets

Sean,

I've had great success with (only) the Elring headgaskets on the BB's...

I torque them down in 25 ft-lb intervals...then bring to the final torque. I wait about an hour and then re-torque to the final numer. Then, I wait an addition 24 hours, and re-torque again to the final torque setting. Although this may seem like alot of work, I've never had a leaker on a BB...

Although a given, I presume that liner projections were checked...and verified to be greater than zero, and ideally at .001-.002"

Regards,
David

 

I have totally stopped using OEM gaskets which are kinda like felpro fiber things with metal in them. I have been using MLS gaskets on everything and they work awesome.

 

I have cheated and used ELring gasket with a more than adequate amount of copper spray. It is important to make sure that the liners protrude a slight amount above the absolutely flat deck of the head. The slight amount is specified and already given above. Even if you have to remove the head studs and machine the deck flat and then reinstall the liners and machine the liners to the right height. This is normally necessary if the engine had overheated and etc ....

 

Yes I used to use OEM gaskets and copper spray which IMO is absolutely mandatory with OE gaskets to get the right seal. Since I switched to MLS no more spray. I got 2 cans of spray copper do you need any?

 

I've had good results with a fine smear of Permatex Form-a-gasket on the head side of the gasket (head side only, so you can still get the heads off subsequently) and using the retorquing method described above by David. However, I usually do one more re-torque after a couple of complete heat cycles - I find that the heat cycles really do have a large impact on maintaining the correct torque setting. I think a lot of head gasket failures are caused by non-mechanically inclined owner/drivers not bringing the car back for a re-torque within a week of picking the car up after a heads-off procedure.

 

You re-torque the head bolts? None of the cars use TTY head bolts? Nobody mentioned angle torquing, I find that odd ...

 

In the next week or so I'm making my own 308 head gaskets out of aluminum, copper, or steel ... haven't made my mind up yet. No matter what I use I'll have to "o-ring" the top of the liners to create the req'd loading. I really like tearing things apart and taking measurements/making wear observations. The price of the Ferrari head gaskets takes some of the "fun" out of it though .

 

Elring (OE) gaskets installed as described by Fastradio and they are installed dry the way both Elring and Ferrari say.


Zero problems

Be certain the head studs are not hourglassing at the base of the top threads. It is a common problem.

 

100% correct. This is an essential step.

David

 

Do you guys reuse the head bolts or get new ones?

 

David- That was a required service after removal of the heads on the SOHC V12 engines. Had not heard it mentioned for the DOHC engines.

Taz
Terry Phillips

 

They discontinued the practice on the 512TR and that is when they started having head gasket trouble.

I try to get several heat cycles in them and do a retorque before even giving the car back.

Those great big TR heads get loose and should be retorqued every valve adjustment. Those that follow Ferraris procedure have trouble with leakage.

 

I built this stand so I could heat cycle the engines and re-tq the heads before putting it all in ... reminded me of community college auto mechanic days LOL ... "fun"

Note the creative use of golf cart for battery power .

cheers
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Lucky- Wow, I bet that rig sounds great. And loud.

Brian- Makes perfect sense. Those heads are huge and are cantilevered off the sides. Any similar issues with later V12s?

Taz
Terry Phillips

 

I Have not built as many engines as some of you I am sure but I have built many. I have a 400hp NA NSX motor going right now. I used the copper spray because I always feared disrupting the HG by retorquing. With non-MLS gaskets there appeared to be no contraindication to using the copper and one of the claimed benefits was superior sealing, so I used it. Even with MLS gasketed cars I have never retorqued a HG and never have had a problem even on a V12. I have no pro backround but the pros I worked beside on Ferraris back in the 80's never retorqued for fear of disrupting the seal. Their claim was that retorque of an old seal was a great way to get a leak. So I never did it nor did I ever test the claim. I have also never done the torque let sit retorque on a new install either because it is fundamentally wrong to tighten a fastner that way. By doing that you fundamentally change the torque signature in unknown ways. For all we know if that is not the factory recommended way you could be inducing more stretch to the bolt and weakening it or putting it to it's yield point. I certainly so not know. I do believe that torquing a head by using a clicker T wrench is bad unless calibrated and I think beam T wrenchs should be used only. I also think the worst way to torque a head is by a factory torque spec in ft-lbs. I think the best way to torque a head is using torque angle.

A long time ago I started this thread on this subject http://ferrarichat.com/forum/showthread.php?t=227245&highlight=tasa

Sean, instead of doing the torque spec per Ferrari on say that 308 motor, being an engineer, can we (I mean you) come up with a more reliable torque angle using a home brewed torque angle signature analysis we can do at home?

 

Ferrari finally figured out how to make torque to yield studs and the 456/550 generation motor benefitted from them. It is a different fastener technology and it took them a while to figure out. Those motors have not really had any head gasket issues.

That technology requires fasteners with a high degree of elsaticity so they can stretch with the expanding alloy block and heads and shrink down again without loss of clamping force. When it works it works well and when it doesnt it is called a 512TR.

 

Brian- Thanks. My 575M seems to be ahead of the power curve on a bunch of early problems.

Taz
Terry Phillips

 

The battery in the golf cart is easy, what I really like is your radiator!

Shouldn't those pipes be 10' long to simulate being in the car?

 

hee hee ... next itteration.

This thing got me started on building a dyno ... one day ... I'll use the energy to heat the pool in the winter LOL.

cheers

 

I'm putting a little radiator on this setup. Since I'm making my own gaskets along with some other "experimental" pieces (I wanted to dial in the cycle TB's on here before putting it all in a car)I want to be able to run the motor for a while out of the car and check things out ... aaah I want a dyno!!!