Felpro Headgasket Thickness

[icanfixall]

I need to know what the compressed gasket thickness is for the Felpro head gaskets. I'm told by a shop I deal with they are 10 thousands thicker than stock gaskets. I know they have to be more than the 54 thousands because thats how much the pistons can stick up out of the block. So if I add 30 thousands to the 54 thousands I will have 84 thousands. I really don't want to install the heads with some clay on them, then remove the heads and try to measure the clay thickness.

 

[Diesel JD]

Why is this important? Just for curiousity's sake or is there a reason that you are concerned?

 

[icanfixall]

My reason for this information is my block has been decked twice now. The first time 5200 miles back was because of the 8 new sleeves. The second time is because sleeve #8 is just a little low in the block after overheating the motor. The oil temp was over 330 degrees when the motor lost a freeze plug. I really don't want "things" touching when I run this new again motor. I tend to be very cautious about everything. I don't have much going on in my life these days. I need something to do other than spend money on her stuff...

 

[jtate]

well if you have that much money to just throw around, please throw some this way it sure would come in handy with doing this head gasket replacement. lol

 

[icanfixall]

I measured the new uncompressed Felpro head gaskets in several places. They appear to be 0.072 thick. Now all I need to do is figure out a way of measuring the compressed gasket on the motor when the time comes.

 

[RLDSL]

How big of a hurry are you in? I've got an engine I pulled a couple of weeks ago that I put new felpro head gaskets in about 4 or 5 months ago. It will probably be a week or so before I can yank a head off though. I have the cherry picker tied up with the new motor till my helper can get over here and there's no way I can lift a head off these days ( Getting old sucks
But I'd be hapy to measure one for you.

----------Robert

 

[Agnem]

Couldn't you just find some way to use a dial indicator to measure the amount of head movement as the bolts are tightened? Wouldn't the difference between the head just sitting there, and being clamped down, be the total thickness less the distance moved? Yea you might have to whack the head with a rubber mallet to make sure it is seated on the gasket first.

 

[icanfixall]

Mel... You da man.... I have been thinking long and hard trying to figure out where I can take the compressed gasket measurement from and you pop this great idea out. I was looking at mearureing from the bottom of the block somehow but haven't found any machined surface that would work. What I will do is start torqueing down the head till I "feel" its seated by crushing the fire rings somewhat. Then zero out the dial indicator and go from there. I know the Felpro head gaskets are 10 thousands thicker than the OEM gaskets so that will help out. I don't have the piston out of the block mearurement yet but the other set was between 47 and 53 thousands above the block. That will put the gap from piston to head at 19 thousands when 30 is factory as I recall somewhere. Even that is suspect because I can't find it written anywhere. Just the spoken work and I like to see it written somewhere as a starting piont.

 

[metrojd]

What was the final out come

Well
What is the thickness?

 

[icanfixall]

I'll have to get back with the info tomorrow. A whole lotta things have happened since this post was started. What I ended up doing was buy another set of low comp pistons with the hard anodised tops. Even then they were still too high out of the block. So I guessed wrong and installed the heads. These were new heads and my favorite shop crapped on the valve job. They couldn't make the .13 thousands valve recession spec and ground 2 of my inconel exhaust valves stems down till they were only about 34 thousands above the spring keepers. I pulled the heads, wasted 2 felpro head gaskets and had another shop do the valve job correctly. I also machined 12 thousands off the piston tops and then had them ceramic coated. Now all the pistons are 24 to 26 thousands above the deck. They all weigh between 1/3 and 1/2 gram between all 8 and balanced out fine. Funny thing the crank needed 43 grams added to it after my favorite shops balance shot... So I will be measuring the used head gaskets in the morning and post what I find. I know there will be some spring in them so the measurement will be close but not exact. I do know one shop that has a good rep all over town.... But I'm not a supporter of them after what they did to my motor. On one day while I was in the shop I saw a worker assembling a 426 hemi fuel motor. They were removing the rods and pistons because of bearing drag on the rod journel radius area of the crank. They installed a narrower set of rod bearings. That wasn't the odd part. The guy would take the pistons and rings and rods, rap a rag around the piston and rings. When he came back I asked what he was doing. He said he was "taking 2 thousands off the big end width of the rods cause they were too close at the crank". I wanted to know if they had a Blanchard grinder and was that how this 2 thous was being taken off.... "Nope.... I just put it on a belt sander freehand. I'm real good at seeing 2 thousands"........ This is why I checked everything I had machined in that hell hole shop..... Sometimes a bug.... Sometimes a windshield.....

 

[towcat]

gary- It would prolly do you some good if you told the rest of the gang what you did for a living for years so that they can understand your penchant for knowing exact measurements

 

[icanfixall]

For those that don't know what I retired from 15 months ago I worked in a machine shop on the large turbines and associated valves and equiptment found in steam geaneration units up to 1100 megawatt nuclear units. The turbine rotors weighed as much as 160 tons. We would spin them up to about 500 rpm in an ARD balance machine and bring them in around 2 ounces. We had a verticle lathe that has a 23 ft rotating table. We did all the big stuff from just about every generating unit anywhere, even Mexico would send us the "special stuff" because we were the only shop that could handle it.. We did lots of third party work too for places like metro water balancing the 15 ft diameter pump impellers. I really liked my work but when 16 jobs were on the block I looked at the money, my age of 54 and what I (the wifey) wanted to do with the rest of our lives. I took the money and ran laughing like a school girl... Haven't looked back either. Well enough about the past. The Felpro head gasket after compressing under 110 lbs of stud torque is 63 thousands. The uncompressed thickness was measured at 74 thousands. I made these measurements over the entire gasket surface so they are correct.

 

[Agnem]

Any of that work come in by rail?

 

[riotwarrior]

The guy would take the pistons and rings and rods, rap a rag around the piston and rings. When he came back I asked what he was doing. He said he was "taking 2 thousands off the big end width of the rods cause they were too close at the crank". I wanted to know if they had a Blanchard grinder and was that how this 2 thous was being taken off.... "Nope.... I just put it on a belt sander freehand. I'm real good at seeing 2 thousands"........ This is why I checked everything I had machined in that hell hole shop..... Sometimes a bug.... Sometimes a windshield.....

Um....ya he can eyeball make that big bull 2 thousandths... Not the kinda thing we did when I worked for South Okanagan Speed and Equipment I'll tell ya....

The Felpro head gasket after compressing under 110 lbs of stud torque is 63 thousands. The uncompressed thickness was measured at 74 thousands. I made these measurements over the entire gasket surface so they are correct.

You know by now I'ld a thought u would have come up with or invented some sorta laser mapping system that can scan that gasket surface and give you even more accurate measurements in the neighborhood of 0.000000000000000000000000000000000000000000001

 

[metrojd]

Retirement???

Retiremant??? Whats That????
Congrats on the Retirement
Thanks for the response.

John