Author Topic: Pilot Head Gaskets - adjustable thickness  (Read 2132 times)

Moskito

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Pilot Head Gaskets - adjustable thickness
« on: March 07, 2008, 08:09:06 PM »
I finally got off my butt and got these going.

What I have for the Pilot guys is a new style head gasket for the FL-400 top end.

They are a peel to thickness setup.

The gaskets are .048" thick aluminum, composed of .002" thick layers.

You can peel individual layers off to get to the desired/needed thickness.  This will let you adjust your compression very precisely.  They'll work great for you guys running cut heads.

I used a set of gaskets made from this stuff years ago on a two stroke square four engine (Suzuki RG-500 Gamma).  They worked beautifully.  When I did the gaskets for the Gamma, the material was sent to me and I had it laser cut to the desired shape.  I've been trying to find this stuff for years and finally came across it.  I figured that it would work perfectly for anyone that's building a Pilot engine.

You can use them on stock engines to modify compression too.

They don't need the sealing ring around the bore like you find on a stock or after market gasket like a Cometic.  The aluminum is soft enough that it will seal, yet not so soft that it will blow out.  They were tested up to 185 PSI on an engine that would turn 12K, with far less gasket surface area than you find on a Pilot, and I never had any issues with them.  I had the heads off the Gamma at least a dozen times and was able to reuse them over and over without any problems.

Cool thing is that you can peel them into two .024" pieces (two for one, if you will) and then work from there.  I believe that a stock gasket is .022", but don't hold me to that - it's been a LONG time since I've messed with Pilot stuff.

I'm asking $35.00 a piece.

PM me if you're interested.
Moskito - Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming \'WOW-What a Ride!\'

PilotHawK

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Pilot Head Gaskets - adjustable thickness
« Reply #1 on: March 08, 2008, 05:17:49 AM »
Sounds like an ideal setup. Put me down for 2 of them.

Adnoh

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Pilot Head Gaskets - adjustable thickness
« Reply #2 on: March 08, 2008, 03:49:35 PM »
I have a question. I like the idea of peel to thickness. If as you mentioned it's good for the guys running cut heads. This is my question. most cut heads have already milled and cut and the squish is factored in reducing this squish clearence may lead to tolerence being to tight. If it was to  be used by those with un cut heads it will increase compression and the un milled head squish clearence has a greater clearence than those who have had then cut,milled and clearenced . I've been wrong before so feel free to inlighten me.  I have a couple of head gaskets layin around would you like me to measure them up for you. Thanks Adnoh

Moskito

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Pilot Head Gaskets - adjustable thickness
« Reply #3 on: March 08, 2008, 05:01:54 PM »
You are correct - it will change squish clearance.  If you're setup already is correct, then you'd just peel on down to the same thickness as a stock gasket - or what ever setup you're using (it was a common practice to delaminate the stock gaskets and just use one or two of the three layers.).

The problem a lot of the guys ran into with the cut head was that they were ending up with too much compression.  These will allow the user to make a thicker single piece (albeit layered material) to lower compression.

As long as the squish band and angle are done correctly, increasing the clearance a few thou won't hurt performance - especially when they're already having problems w/too high of a compression for the setup.

It's sort of a specialized band-aide fix, if you will.

Also, if you have one of these gaskets in hand and then work on doing the head cutting, you can be even more precise in getting the correct clearance.

I would appreciate a measurement on a stock gasket.  As I stated above, it's been a very long time since I worked on Pilot stuff, so the number I posted was pulled from a dark, dusty cob web filled recess of my pea brain.  There's a very good chance that I'm wrong about it. - or it may be a CR500 gasket, since that is what I used on my Pilot engine (was the 500 conversion).

Good question, btw.
Moskito - Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming \'WOW-What a Ride!\'

Weed

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Pilot Head Gaskets - adjustable thickness
« Reply #4 on: March 08, 2008, 07:59:40 PM »
Honda gasket is .025in or .65mm not measured on the crush portion.

Cometic gasket is much thicker.

Adnoh

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Pilot Head Gaskets - adjustable thickness
« Reply #5 on: March 09, 2008, 08:38:26 AM »
Thanks for the reply. I hope you do not mind me asking a few more.  
(1) As you state a few thousands . Will this alow change the the flame front area and condinse it to smaller area on the piston dome. If so will this  require a jetting and maybe a plug range change as well.
(2) Are they avalible for stock to second bore and than up up like 82mm or does one size fit all.
(3) How about a pic of the gasket showing the cooling port locations and sizeing, any benifit there.

The reason I,am asking so many is I 'am in the middle of a rebuid on an engine and might give it a try. Maybe send out with a notice that this gasket may effect jettting. Hate to see some one buy than burn hole or sieze because no one told them it would change there jetting.If choosen I will compare to stock and post pros and cons if any Thanks, Adnoh

Moskito

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Pilot Head Gaskets - adjustable thickness
« Reply #6 on: March 09, 2008, 10:09:45 AM »
First off - I just figured out your screen name. DUH on me!   :roll:   LOL!

Ask away and I'll answer what I can.

No pix yet.  I hope to pick them up from the laser cutter the end of this week.  They are a direct copy of a stock head gasket, so no changes at all.

Good idea about the larger bores.  I wasn't thinking about that at all.

As easy as this stuff is to trim, I believe you can make them fit a larger bore w/o any problems.  I would go about it by putting the gasket on top the jug, putting the correct bore diam gasket over that and then use a #11 exacto blade or a small file to open up the bore on the gasket to the correct size.

- to answer #1, you obviously tune to a more precise level than 90% of us.  You may notice the changes, while the rest of us won't.

In general the guys that own Pilots tend to jet on the rich side for longevity of the engine, so the minor changes you'd see won't be an issue.

My main reason behind these gaskets is to help out with the guy that has a head that's been cut too much and needs to lower compression.  Correct me if I'm wrong, but wouldn't this do just the opposite of question #1?

And, if you have a setup you like, gasket wise, you can just peel these down to the same thickness and not change your tuning at all.

Overall, it's just an optional part for the FL400 that will allow you to drop or raise the compression and the way the engine works with it - what ever your heart desires.
Moskito - Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming \'WOW-What a Ride!\'

Adnoh

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Pilot Head Gaskets - adjustable thickness
« Reply #7 on: March 09, 2008, 11:48:09 AM »
In lawyer talk, ask and ansawer. I sure like the benifts the gasket may provide. The best one I can think of why cut the head to dial in than reweld and cut again when the gasket which is cheaper can do some of the work for you than cut once and reshape. On the raising the already cut head ya It will do the job I just hope they take the flame front into account. It will travle futher across the piston dome and trap less intake charge in the squish to cool piston dome. I see a good aplaction for the gasket where a cut is made to accomadate low to high allitude ridding. For those going from sea level to an higher alltidude you just simple increass the compression a little to ofset power lose and rejet and do plug change. Keep em comming I like new idea's that benafet ridders.

Moskito

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Pilot Head Gaskets - adjustable thickness
« Reply #8 on: March 13, 2008, 01:12:26 PM »
Got the gaskets today.  They came out pretty good.

Here are two shots - one of a gasket and one of a peeled up layer so you can see what I'm talking about:


Moskito - Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming \'WOW-What a Ride!\'