Was That Head Gasket Red Or Gray?

[Dan Hodges]

In November of 06 I bought an 1179 kit directly from Wiseco and the kit came with a composition head gasket that was red in color and indentified by Wiseco as a CFM-20 head gasket part # W2723. Two weeks ago I purchased another head gasket from Wiseco under the same part number however it was gray in color but was of the same configeration as the earlier one. Back in 1990 I also bought two head gaskets from Wiseco and both were red and the same part number was used then. I called Wiseco about this and they informed me they were not familiar with the red gasket but that I should call Cometic Gaskets who make them. I called Cometic and they said that they have never made a red one. I told them that I have a new unused red gasket and a new gray gasket and both have the same part number and both were bought directly from Wiseco after which Cometic stated they had never made a red one. Obviously the stock graphite gasket is best however it won't work on a bore larger than 72.5 mm. I have the red gasket in my 1179 and have had no problems other than the fact I had to re-torque it twice during the first 1500 miles after the initial re-torque it got after running it for 5 minutes in the garage after it was first put together. The stock graphite gaskets don't require a re-torque but will not work with the big bore kits and so as far as I know the gray CFM-20 gaskets that Cometic now makes is the only choice out there for the XS 1100 with a bore larger than 72.5 mm. The difference in the color of the gaskets is cause for some concern to me and so my reason for posting this is to ask the question, have any of you observed a difference in the color or material of the head gaskets purchased from Wiseco seperately or in the piston kits they sell. Lastly, I bought a new stock head gasket from Yamaha to add to my parts inventory and the darn thing was $ 157.00 less tax which is about a hundred dollars more than the one from Wiseco and so it has to be very good graphite. According to Cometic, they quit making graphite and asbestes gaskets because of restrictions by the EPA, but who knows. Thanks for your input. Dan

[DiverRay]

Dan,
From your post, I think what you are trying to say is I just got r*ped, and want to know if I needed the vasoline. The BIG difference between the gaskets SHOULD be the need to tighten the head bolts once again. If the one from Wiseco fit, and DO NOT need the extra work, that is the one I would use. JMHO

[Crazcnuk]

The one I got from Cometic is copper!

[TopCatGr58]

Obviously the stock graphite gasket is best however it won't work on a bore larger than 72.5 mm.

Hey Dan,

I did my 1179cc/74mm little big bore back in 2000, and got a Cometic gasket, and I'm pretty sure it was the grey GRAPHITE silver colored type. Just reread what you said above, and I see you're talking about the OEM/STOCK gasket. The Cometic one was made for the larger piston bore.

It's been on there for 8 years now, no head gasket leaks, plenty of compression, etc.! It had the reinforced metallic rings that fit around the piston area.

IIRC, I did retorque it once after bringing up to normal temps and cooling down. The engine has gotten very close to overheating due to some severe stop and go summer traffic with no ill effects!

My big bore kit was a bit strange though, it was cobbled together by the racing bike machine shop that was to do the boring. They had tried to order the kit from Wiseco for several months, but none were available, and so they started contacting other shops and came up with 2 pistons from one place, 1 from another, and 1 from a third place. SO...they ordered the gasket from COMETIC as far as I can tell, was the correct bore/pattern for the bike!!

T.C.

[Dan Hodges]

Originally posted by DiverRay
Dan,
From your post, I think what you are trying to say is I just got r*ped, and want to know if I needed the vasoline. The BIG difference between the gaskets SHOULD be the need to tighten the head bolts once again. If the one from Wiseco fit, and DO NOT need the extra work, that is the one I would use. JMHO

They all fit and all composition gaskets require re-torquing. The gray colored gasket is the latest and so lacking any evidence as to which is better I'll use the gray one. I thought someone on here would have recalled the color of the gasket they used but I suppose not. I'm sure there must be a difference in them but I don't know what it is. Naturally, I always keep an industrialized size quanity of vasoline handy in my garage as I seem to never quit getting hammered on Eleven parts.

[trbig]

Both the stock gasket I got from the Partsnmore gasket set, and the one I got with my Wiseco 1179 kit were the grey ones. I haven't seen any red gaskets on any of the motors I have gone through??

Tod

[Dan Hodges]

A Gasket Of A Different Color

Originally posted by TopCatGr58


Hey Dan,

I did my 1179cc/74mm little big bore back in 2000, and got a Cometic gasket, and I'm pretty sure it was the grey GRAPHITE silver colored type. Just reread what you said above, and I see you're talking about the OEM/STOCK gasket. The Cometic one was made for the larger piston bore.

It's been on there for 8 years now, no head gasket leaks, plenty of compression, etc.! It had the reinforced metallic rings that fit around the piston area.

IIRC, I did retorque it once after bringing up to normal temps and cooling down. The engine has gotten very close to overheating due to some severe stop and go summer traffic with no ill effects!

My big bore kit was a bit strange though, it was cobbled together by the racing bike machine shop that was to do the boring. They had tried to order the kit from Wiseco for several months, but none were available, and so they started contacting other shops and came up with 2 pistons from one place, 1 from another, and 1 from a third place. SO...they ordered the gasket from COMETIC as far as I can tell, was the correct bore/pattern for the bike!!

T.C.

Cometic makes the gaskets for Wiseco however according to Cometic, thay have never made a graphite gasket for the XS and the gray one you used was probably the Cometic CFM-20 type. All of the XS head gaskets made by Cometic are of the CFM-20 type which have the steel cylinder rings and the bore is 75 mm. I mentioned the stock gasket because I bought one for a spare should I need one for a stock bore motor someday. In the late 90's, Wiseco changed the design of the XS piston to the ones being sold now. The previous design used a thicker top ring, had a different skirt design and the ring lands didn't have the compression rings used on the new/current design. In 96 I bought a set of Wiseco pistons through Hickory Performance in North Carolina and the kit came with the red head gasket and early design pistons. I didn't use them at the time because I got sidetracked on my FJ big bore project and by the time I got ready to do my Eleven in November of 07 I was told that they had a new and improved piston available after which I ordered a set directly from Wiseco. I got the new pistons however the kit came came with a red colored gasket which I used. My red gasket combo is doing fine but I only have about 3,000 miles on it and 3 dyno test. I was brainstorming gaskets in an attempt to decide what material to use on my 1311 project. Cometic say's they can make a 78 mm bore gasket from the current CFM-20 design which is probably the route I will go. Of course Cometic makes a killer MLS gasket for the FJ but of course it's not available for the XS, of course. Thanks for your input. Dan

[Bigleo]

Hi Dan, I have bought two 1197 kits from Wiseco, both came with grey gaskets. I retorqued after 50 miles, and the head nuts were quite loose, I probably would retorque after the first run next time round.

[Crazcnuk]

"All of the XS head gaskets made by Cometic are of the CFM-20 type which have the steel cylinder rings and the bore is 75 mm"

Cometic also makes 'Dead-soft Copper' head gaskets, for the XS1100. My pistons are 2.945 inches, or 74.8mm, and even adding on the clearances, this gasket has slightly larger bores than my barrels (I assume the 75mm you mention).

[trbig]

"I retorqued after 50 miles, and the head nuts were quite loose, I probably would retorque after the first run next time round."


What happens with the new head gaskets, is that you get the nuts tight, then fire up the motor the first time. When the head and cylinders get to operating temps, they expand from the heat towards each other and compress the head gasket further. When it cools back down and the metal shrinks back to normal, the gasket remains compressed and the head nuts are now loose.

If you're cheap like me and re-use head gaskets, this process has been done already and a head usually remains torqued and tight after installation.

Tod

[Dan Hodges]

Head Gasket's & Pistons

Thanks all for your imput. All composition head gaskets require retorquing after an initial run in of the motor. After this and the first 50-100 easy miles the head should be torqued again after which it should be good to go. The high end blue Fel-Pro head gaskets that I use in my race car motors also require this technique. Dead soft copper gaskets were once popular in very high compression race car motors however they are not widely used today except in blown motors and some Nitrus applications. They are however still widely used in very high compression big bore drag bike motors, Pro/Stock and such, however when these copper gaskets are used either the head or block must be machined for steel "O" rings around the bore and in the case of motorcycle engines you have to "O" the head. The stock Yamaha head gasket is of a graphite construction and does not require this re-torque even though it's a good idea to check the cylinder head torque at the factory recommended 600 mile breakin check up. When you use a dead soft copper head gasket on the Eleven or any of the other air cooled in line fours for which it is available you must use some type of sealant around the cam chain cavity and even then it's prone to leak oil around that location however in a drag bike this is no big deal plus the fact it can be used several times. Personally, I will not tolerate a motor that exibits the slightest degree of oil leakage and one that is wet, weeps, or drips won't get it and so I have not, nor will I ever assemble a motor with a used composition or steel gasket but would a copper one but I don't use copper and won't because of the before mentioned reasons. To put a motor together with a used head gasket is in my view, penny wise and pound foolish and with my luck, I won't take a chance with a used head gasket because at fifty bucks apiece they are cheap insurance against leakage. I am posting pictures of the three gaskets available for the XS. One is the stock Yamaha graphite gasket which is good for up to a 72.5 mm bore and the top one is the red CFM-20 which is good for up to a 75mm bore and the middle one is the grey CFM-20 75 mm gasket made by Cometic that replaces the red one. You might want to check out Cometic's web site.



Also attached are the three pistons I spoke about. On the left is the stock 81, the latest design Wiseco is in the middle and the first design Wiseco is on the right. There are several key features about the three pistons that are different and you can pick up on the differences by studying the pictures.



Check out the skirts and the ring lands.

[ClarkGriswald]

Wow thats some good info, your not kidding about those pistons. So much more skirt and not only differnet ring lands/grooves but how low on the piston that one set of holes is in the oil ring groove.
Got a feelin I'm going to be needing this type of knowledge soon hehe.

[Crazcnuk]

Here is the RK Eng piston.

[Dan Hodges]

Piston Ring Drag

Originally posted by ClarkGriswald
Wow thats some good info, your not kidding about those pistons. So much more skirt and not only differnet ring lands/grooves but how low on the piston that one set of holes is in the oil ring groove.
Got a feelin I'm going to be needing this type of knowledge soon hehe.

I used a small fish type weight scale to measure the ring drag and or resistance needed to pull these pistons through a properly finished bore with the rings installed and the first design Wiseco required 3 pounds more to pull it up the bore vs the stock one and the late one required less than the stock one even though it was 2.5 mm larger. The 1st. design Wiseco piston used a .047 top ring and the 2nd. design uses a .039. top. Both pistons use the same 2nd. compression ring and low tension .109 oil ring package however the 2nd. design has anti-detonation rings/groves on the ring lands and the second ring uses a larger ring end gap. The stock piston uses a .047 top compression ring and a .059 2nd. and a standard tension .109 oil ring. The large skirt area of the 1st. design Wiseco would also create more drag but would offer more cylinder wall support which would be a positive if you were running cylinder walls that were on the thin side, something less than .080. There is a lot of power to be had with thin low tension rings however it's a fine line between too little and too much. You can also employ use gas ports to enhance the seal of the top ring however this is race stuff and top ring life will decrease dramtically. From all of this, you can determine which one of these combinations will make the most power and which one will last the longest. Good luck with your program. Dan

[Dan Hodges]

Originally posted by Crazcnuk


Here is the RK Eng piston.

What is the dome volume on this piston?