Are Tiger heads too soft for boost?
 

I have had terrible luck with nitrous and this tiger headed 537. The heads actually started to go concave at the center ports and I resurfaced them 3 times. This time we had to go .010 cut. I was using .060 cometics this last time and pulled 20* timing for only a 200 shot and still torched the block and head. I am selling all the nitrous stuff and putting on my F-2 Procharger, my question is, will these heads work with about 10-15 lbs. boost?

Steve

A guy in our nostalgia group has had a similar experience running NA only. Wonder if a good heat treat on the heads will help fix this issue.

It is a cooling problem between the center exhaust valves. Drill some holes, put a second water pump on and you will get 50 hits on the gaskets. That's around how many Rex gets.

I believe na they are a very good head. With power adders I have heard of some problems. What style combustion chamber are you using?

Where should I drill holes???? Should I just sell the heads and get something a little more durable??

Steve

I would and if you're going run nitrous get the chambers softened.

Nitrous is for sale and i won't be using it anymore. I am putting my Procharger on but before I do, I need to address this issue.

After drilling today, I notice that it is completely solid between the 2 center cylinders. I assume you drill completely through, parallel to the stud and exit out on top of the head.

Steve

I ran no water and methanol....normal exhaust temps and torched heads every couple passes... take what you want from that... I know sikgoat gave up on tigers and boost and went to eheads....

Big Chief had same experience

How's your guys experience with boosted engines ?

The heads need a Cryo temper session !

So does anybody want to buy a real good set of Tigers?

We ran 2 sets of early Tiger heads. Sprayed 600 HP nitrous on these combinations. Our only real issue was the lack of clamp load available on the two step studs that go between the intake ports. Ended up boring those holes for straight 1/2" studs and installing step washers. We used copper gaskets, O-rings, and a wet deck. These heads sealed better than the E-heads for us. FWIW.

How many runs did y'all get before gaskets replacement?

Maybe this could be a option for you? I have no personal experience with them.
http://forums.maxperformanceinc.com/...t=tiger+insert

Tiger Deck inserts
 

[QUOTE=p4msi1;5923779]I have had terrible luck with nitrous and this tiger headed 537. The heads actually started to go concave at the center ports and I resurfaced them 3 times. This time we had to go .010 cut. I was using .060 cometics this last time and pulled 20* timing for only a 200 shot and still torched the block and head. I am selling all the nitrous stuff and putting on my F-2 Procharger, my question is, will these heads work with about 10-15 lbs. boost?


Steve,

I have copper inserts that can be installed to fix your problem. I would like some feed back from some of you that are using them.

We have had good results with the new inserts. We have done 15 to 20 sets of heads and have not heard of any problems other than the ones mentioned below.

I did one set of heads that was running nitrous and went lean. The alum around and under the insert was melted away and almost all of the way thru to the other chamber. The inset looked like it did when it was installed. My customer wondered if the melted area could be welded up without removing the insert. My first thought was no, then I said, it held up to nitrous, maybe it would hold up to welding also. I don't know how or if it was repaired. I would be interested in hearing if the head is fixed and how it was done.

A second set of heads had a problem after several initial dyno pulls. I'm not sure yet what caused the issue, but I will let you know when I find out.

Thanks

Glenn Sedig

Cell 815 441 0931

Yup, considered this option also.

There is no clamping issue. There is no softness issue. There is a heat issue. Remove the heat, remove the problem. It's that simple. Using the insert by itself will not resolve the issue.

We were getting 25-30 runs on a set of copper gaskets. We were running the Flatout coated copper gaskets and the coating would eventually fret through and we would get some water seepage. Occasionally, we would lose the seal between the center cylinders because of the heat concentration with the two exhaust valves. We did not have that modification to the head in the middle that is supposed to cure this. For our match race type deal, this was about half a year for us.

One item in this quote, I am not sure about. I do not know if John was still using the goofy 1/2"- 7/16" step studs in the 2 center locations in his maximum effort Tiger heads. I do not like the idea of having 2 of the 10 clamping studs holding the head down having to operate at a 30% reduced clamp load. IMO, that can only lead to warping and leaking when the stress and heat are really on. If he had full 1/2" studs and equal clamp load, I agree.

I run all 1/2" studs.

OK John, stop teasing, I will pay you for advise on this issue, please call me 540-967-4836 Shop or my cell 703-615-5027 so we can talk. I know you have many hours and much money fixing this and this is turning into a lot of money for me also. Like I said I am willing to pay you for advise, not looking for something for free.

Steve

Absolute truth right here^^^

Question is do you really know what the clamp load actually is Across the head ?
Get some pressure paper and do a clamp load test , bet you'd be surprised/ disappointed. I Have not done this myself however I know that every time I ever test anything for real, I'm always disappointed. Lol

I ran all 1/2 studs as well along with 4 added bolts....still torched heads with acceptable temps....my heafs got welded on after every couple to 3 passes....
Sounds like Langer is AP''s bitch...free parts go a long way... the heads make massive power no doubt....but...
There is an issues...

I actually paid for my castings. I said what the issue is and how to correct it.

So how do you correct it on methanol and no water?

Run water in the head and not the block.

I ran no water at all... it was a straight methanol blower application where we had to build heat in the motor to make a pass...
If I need water, there is a problem...

I am aware of the paper and the process and I have been to a seminar by Fuji Film at the AETC conference years ago. But to answer your question, no, I have not performed the process on any Pontiac heads. It would be educational and an excellent idea for people having gasket issues like traditional Pontiac's. I have looked at pressure prints from SBF's and SBC's. You can clearly see the advantages of the 5 bolt pattern like a SBC uses. But to your point, the LS engine that everyone seems to be in love with is a 10 bolt head. You can bet pressure paper was used to develop an even clamp load with just 10 bolts. You really bring up an excellent point in a way of how far behind and difficult is to develop a niche engine like a Pontiac vs a Chevy, Ford or Mopar. Just developing a better clamp load for our heads would take some of that very expensive paper, lots of time and effort to make it happen. And it's just one tiny part of the overall engine package. All of these details have been worked out by the other guys.

Now this was a much needed conversation. I picked up a few morsels of information and a few people to contact. I am trying to compete in the Virginia's Fastest Street car competition and the car is fast enough to get on the list but can't live long enough, so I just need a little help from my brothers. Thanks for all the input guys!!!!!!!


Steve Prudhomme

Copper Inserts
 

The heat generated by 2 exhaust valves side by side in the center of the head softens the alum enough to cause the web between the center cylinders to deform down .002 to .004. The ridges in the head gasket also indent into the alum web by several thousands of an inch. The other webs with 2 intake valves side by side show no distortion or effects from heat. After the center web is pushed down, the head gasket has less clamping pressure in that area, which slows the disipation of heat causing the head gasket to burn and allows combustion pressure to pass between the cylinders.

All of the heads I have put inserts into regardless of the brand have had this same problem.

On my engine with over 15:1 compression I have had no problems. When tearing it down, the area of the gasket where the insert is, shows no sign of heat or leakage. The insert is pulling the heat away from the area so that the insert in the web does not get hot enough to deform. The copper alloy insert will also take much more heat that is generated in the web area before it gets soft enough to deform.

Jim is right, the problem is too much heat. So the answer is to get rid of some of the heat or find something that will hold up to the heat. Adding water holes will get rid of some off the heat and the copper inserts will hold up to the heat.

One or both of the fixes can be a solution. With that said we will still have problems in the center web area on high hp heads because of the heat and the thickness of the web.

Cool.


I applaud everyone in this thread for keeping at it.



Changing HG every 50 passes is not what I consider fun.

I’ve raced Pontiacs since the 80s and still do. Obviously not at this level cause I did not know there was such a problem blowing head gaskets. Some of you guys are getting10-30 then changing?!! I’m amazed you’ve hung on this long. Kudos to you!

Well it use to be 3-5 passes

How many passes are you getting now ?

I put the inserts in my E-heads beginning of last year and went from having some leakage start between the center cylinder in 10 to 15 passes to now going 50 to 60 passes without changing head gaskets. So I can verify that the inserts definitely work.

Also I will be running a set of the new tigers for next year and I dont think there is going to be a problem. They have water going between the two exhaust valves and I will have the inserts put in.

EHTTFMF

Don’t you mean: THTTFMF?



You’re rich.

You need to be rich to be competitive with a Pontiac...

You need to have money going that quick with any engine/car, trust me it ain’t cheap!


GTO George

So, the new Tigers have water in there and the old ones did not?

Youve got to be a committed racer to put in that much time and money. I guess I'm lazy because I wouldnt want to invest that much time and money. It looks like those guys on streetoutlaws race on the weekends and work on their cars all week..I couldnt do it. These too many other things to do. I used to pull the motor and have it freshened every 3 ish years which I thought was a pain,,,lol. If I Had to pull the heads off every 10 runs Id say the hell with it. The slower ,low maintenance stuff is fine for me.Im sure you done it so much you could pull the heads and have them back on and valves set in a hour.

Glen, Give me a call 540-967-4836 or 703-615-5027

Steve

Glenn - what's the going rate on a set of e heads to have this done? My motors coming out this winter. May have this upgrade done on them.

X2... may be interested in the future myself

It would be nice if AP would state what the difference is with the new casting vs the old casting to help fix the heat issue there

I'm not a tiger expert but I think the original tigers did not have water between the center cylinders and new ones do.

Langer or Dwight can chime in.

That’s why some switched over to the Shafiroff 1000 hp motors for 15kthat you can run forever.

I would rather put Head gaskets on a Pontiac every 10-15 passes then put a Chevy in my Pontiac.