Topic: will i need to change my cam chain or shorten it if i run thinner gaskets

[bucky katt]

i have found thinner than stock, copper head gaskets and thinner than stock (.005" ) base gaskets and other than checking clearances between piston and valves and head, is there anything else i need to do? i am looking for as much compression as i can get with a relatively stock motor and bore. and a honda (cb750f0 cam)

[dave500]

ive done it to a 550,clean all the surfaces perfectly with metholated spirit,ive run the motor for half an hour,no leaks,havent used it in a bike yet.dont bulk it on,a thin even smear,keeping out of the oil gallery areas.

[bucky katt]

looks like a head gasket as thin as .005" is also available as well as the .005" base gasket. are copper gaskets compatible with street use?

[BLUE71TURBO]

Copper gaskets are the only way to go in my opinion. As for the cam chain, no you won't need to change it or shorten it.

[bucky katt]

cool, so i can get a bit of a compression increase just by going to MUCH thinner gaskets. i'm thinking .005" thickness base AND head gaskets. because the motor is in such good mechanical condition i dont want to have to buy new pistons and possibly re-bore for more compression. well, if i can get this home stereo equipment sold, dynoman is going to be selling me a new head gasket to start with. if i dont have to pull the barrels i wont. oh, and some modeling clay for checking clearances.

[mlinder]

Won't have to change chains, but will have to time a bid differently. Timing advances a little with thinner gaskets.

[bucky katt]

ok so the adjustable cam sprocket i did needs to go on now then?

[bucky katt]

i love it when a business owner or operator has the integrity to try and talk me OUT of buying a part because they dont think it would be satisfactory for me. the reply i got when asking about the thin copper head gaskets was this



"We do not have thinner head gaskets in CFM-20 fiber material. We can make a thinner copper head gaskets, but do not recommend them. They are strong, but not good on oil control."

that is cut and pasted directly from the email reply i recieved, in less than an hour at that.

[bwaller]

Copper is probably first choice where the top end is off often (racing applications). On the street where you want oil tight the fibre will probably get the nod. Instead of a copper base ask them for viton coated steel, not sure 0.005" is available though

[bucky katt]

the thinnest in the coated steel is .010" any clue as to how thick the original one is?

[754]

Are you milling the head? If you want to save time and bux, try to lap it.. get a big flat surface and big sandpaper (like stroke sander castoffs or similar).

 Blue the head or make felt pen marks, work it a bit and check if its near flat, work it till flat.

 I am not a big fan of milling heads unecessarily.

[bucky katt]

Mrieck suggested trying the thinner base gasket first. then try milling a bit off. it's possible, if the stock base gasket is that much thicker, that just the thinner base gasket will work. this is all a long ways off though as all i want to do right now is ride the thing.

[mlinder]

Doesn't cost much to have the head decked. May want to look into that.

[bwaller]

Stock base gasket is 0.5mm (0.020")

[Terry in Australia]

I wouldn't bother using copper unless you're getting them really cheap Fuzzy, I've never had a problem with head or base gasket leaks because I torque 'em down to 20 ft lbs, (in small increments) leave them overnight, back 'em off, then torque 'em down again next morning, and by now I've crushed them fat gaskets down to half their original thickness anyway. Cheers, Terry.

[bucky katt]

50 to have it milled. i think i'm going to send the 75 750f head to have that done, and new guides at the least.

[NitroHunter]

My .02 is to go for a zero deck first. Deck the block before the head, get that tight squish band working for you.
Don't think I'd be inclined to use a head gasket paper thin! If chamber volume is that important, mill the head & use a decent .040" copper gasket, for sure you won't have leaks and you can reuse that gasket for years to come.