Potential Group Purchase - Wiseco GS650 741cc pistons

[Chuck78]

Head Gaskets requested from the last 2 ot 8 pages on this thread:
3+ - Chuck78
2+ - tkent
2 - Ace07
2 - frankenwabbit
1 - gilldog
1 - Tooheys
(?) - old colt
(2) - complete cafe racer

I'm in contact with John Baker @ GasketsToGo.com again and should have the templates to him this next week for resizing oil passage/cam tunnel seal areas for switching over to MLS gasket material and then ready for approval & payment.

[Tooheys]

Awesome. Just let me know when I have to pay. I would need mine shipped to Aus. If anyone else needs it shipped here too I would be happy to re post them to save on costs for everyone.

[Ace07]

Yeah!!!! I am ready to get the ball rolling again. Feels like ages since I worked on the bike.

[frankenwabbit]

oooh...i can't wait!!!! (haven't done squat with the project....what a surprise)

[gilldog]

That's Brilliant, gives me some incentive to start stripping the engine

[Chuck78]

FYI, browsing for GS1000 1085/1100 piston kits, I discovered that DynoMan Performance offers custom GS550 big bore pistons at 630cc and a Comet head gasket to match! A bit pricey, but available for those who don't want to wait for a few others to sign up for a minimum batch of 12.
the old Wiseco kit on one of the 550's in my garage is a 610. The DP630 is a step up from that, but still probably has no edge on a stock 673cc top end swap. We really struck gold with the 650 head combined with a 740cc piston, & for a killer group purchase price...

DP 630/GS

630cc 60mm 10.25:1

For 1977-82 GS550 Suzuki 2-Valve engines Kit includes: (4) Pistons, (4) Ring Sets, (4) Piston Pins, (8) Retainer Clips, and Cometic CFM20 Head Gasket Features: ~ Smooth Finished Crowns ~ Accumulator Grooves Weight: 171g

[Doc Brown]

dOC bROWN 82 gs650E.jpgAre these pistons an upgrade to the OEM 650 pistons? if they are I would be in for a set for my 82 gs650e.

[Chuck78]

Yes, 650 is 673cc and ~9:1 compression ratio. These are forged cnc machined 740cc 10.25:1.

There is a fellow in England now looking to get Wiseco to make another batch of them. He started a new thread on the subject. With you, I think that makes the 3 set minimum that wiseco requires

[5hrine]

Yes, 650 is 673cc and ~9:1 compression ratio. These are forged cnc machined 740cc 10.25:1.

There is a fellow in England now looking to get Wiseco to make another batch of them. He started a new thread on the subject. With you, I think that makes the 3 set minimum that wiseco requires

I was trying to get a group buy going, but not had any takers yet and I think I may have got some now, but I will be interested in buying a head gasket when the group buy some.

[5hrine]

Head Gaskets requested from the last 2 ot 8 pages on this thread:
3+ - Chuck78
2+ - tkent
2 - Ace07
2 - frankenwabbit
1 - gilldog
1 - Tooheys
(?) - old colt
(2) - complete cafe racer

I'm in contact with John Baker @ GasketsToGo.com again and should have the templates to him this next week for resizing oil passage/cam tunnel seal areas for switching over to MLS gasket material and then ready for approval & payment.

Can you put me down for 2 - thanks

[prichmon]

I may be interested in taking part. LMK if the group comes together please.

Rich

[Chuck78]

Gasket Order ASAP - INFO NEEDED from you!

NOTE: I am editing the updated running total of what has been requested in this quoted text below:

Head Gaskets requested from the last 3 of 8 pages on this thread:
4 or 6 - Chuck78 0.8mm & 0.9mm & maybe 1.0mm
2 - Tooheys 1x 0.8mm and 1x 0.9mm. pd in Aus
2 - Ace07 1.0mm?
2 - tkent02 1x 0.8mm, 1x 0.9mm-or-1.0mm?
2 - 5hrine 0.8mm? or 0.9mm in U.K.
2 - frankenwabbit 0.8mm and 0.9mm
1 - old colt 0.8mm thickness
1 - gilldog 0.8mm in U.K.


2? - complete cafe racer
???prichmon??? I think he was needing pistons, too, so maybe not just yet on the gasket

John at GasketsToGo.com is ready to make these gaskets for us... I am needing a better count on quantities from all of you. The minimum order is 5, and if I can't get definite answers from all of you, I will probably just place an initial order of over 5 or about 10, and let anyone else come in later and try to get another larger group of 5+ together.
If I got 4 gaskets myself, and everyone who has spoken up in the past few pages of this thread does in fact buy some

The price break for 5+ is $80/gasket last I talked to John about pricing. one gasket made after the fact will cost you $120. I believe the next price break quantity is 20+ or 25+.


I need someone with a stock GS650 gasket to do me a favor. Mine was missing the corner oil pressure passage stud hole seals that insert into the head gasket. Can someone measure the inside diameter of these? From going off of a GS1100G head gasket that I used on my GS750/850-920cc build, it had a 13mm stud hole oil passage in the MLS gasket, and the hole in the head is only 12mm. Tentatively, I told John to make our gaskets 12mm on the corner oil stud holes, as the GS650 head or block that I measured was 11mm i.d. on the oil passage corner stud holes.
The tunnel is already resized on the 650 gaskets vs the 550 with the larger tunnel that uses the cam tunnel rectangular o-ring.
John says that for the bore size, we want a half millimeter larger hole in the head gasket for the piston bore, so 65mm pistons will equate to 65.5mm gasket bore.

John also tells me that if we want a 1.0mm compressed thickness head gasket, to order 1.1mm, as they generally compress about .1mm when installed.

OldColt was saying he wanted to run as tight as .030" quench band. i am not sure if he was planning to zero deck his block and run a .030" gasket, or if he was trying to run a thinner head gasket and not zero deck. I myself plan to deck the block closer to a zero deck but not quite, maybe piston down in the hole .005" minimum, The quench distance I would like to arrive at total would be around .039-.045" gasket thickness plus piston down in the hole.
Unless some of you have some flukes with a block that has been decked substantially, or other errant machining from the factory, I think that 1.0mm or .9mm compressed would be an excellent basis to start from. I'd highly recommend everyone decking their block for both a clean sealing surface AND better quench distance and compression ratio, as I recall someone saying that they found Suzuki generally had the engines set up from the factory with the pistons .020" or .5mm down in the hole, stock. and the factory head gaskets if I recall are around .040" compressed.
dialing in the quench distance is an extra bonus in performance, as it reduces the chances of detonation under high heat and load especially on lower octane, and it also boosts performance by adding even more compression psi through compression ratio increase to give the engine even more performance.

running a zero deck and/or minimizing gasket thickness to arrive at around 1mm or .039" quench height will also alter your cam timing slightly from stock, as it will shorten the distance from crank and cams on the taught side of the cam chain, which will advance the cam timing more, which will result in a big boost in low midrange power at the expense of a slight loss in high end horsepower. This can be adjusted through slotting the cam sprockets slightly and using a dial indicator runout gauge with magnet base, a TDC piston stop, and a cam degree wheel to dial in the cam timing to exactly where you want it for making the bike a high rpm screamer, a torque monster street terror, or something with a decent compromise/mix of both.


I need to know ASAP:
*how many gaskets you need
*how thick of a gasket you are wanting (I'd default to 1.0 mm if you are uncertain or .9mm even .8mm if you do not plan to deck your block and you have verified that it is stock height with piston down in hole .010 or .020" (.25 - .5mmm
*when you are ready to purchase and have money to paypal me
*are you needing this shipped outside the contiguous 48 states in the USA?

(I assume John @ gasketstogo will want just one payment to make the lot, but I may see for the 2 of you in the UK and the one in Australia if I can have you 3 just paypal john your own postage amount to have your gasket(s) shipped direct to you.

[Old Colt]

Thank you for the heads up,
Yes count me in for one gasket as close to 0.030", probably 0.8mm to be safe.

[Ace07]

Hey Chuck,

I have unfortuately have not had time to work on my bike in the last two months, but I am still interested in buying two of those gaskets. I am planning on setting the deck height, but I am going to have to do alot more reading on that before I can start it. I guess put me down for 2 1mm gaskets. Also I have a brand new overbore head gasket here, and I measured the holes of it, and it turned out to be approximately 16.75mm in diameter.

[Chuck78]

Hey Chuck,

I have unfortuately have not had time to work on my bike in the last two months, but I am still interested in buying two of those gaskets. I am planning on setting the deck height, but I am going to have to do alot more reading on that before I can start it. I guess put me down for 2 1mm gaskets. Also I have a brand new overbore head gasket here, and I measured the holes of it, and it turned out to be approximately 16.75mm in diameter.

Andy, the 16.75mm opening is the size of the gasket hole, which is meant to accept an inner oil pressure seal. The MLS head gaskets delete this seal and just use the stainless spring steel shim material to seal the oil passages on the 4 corner studs. I need someone to measure the inside diameter of one of these seals that I do not have in my possession. Otherwise we will go with a default of .5mm larger gasket hole radius which I have already discussed with John Baker at GasketsToGo.



We can defer to opinions of Old Colt and other more advanced performance engine builders as to quench height. OldColt seems to think that a zero deck with .030" or .8mm (.7mm compressed) is the ideal minimum. If the installer is not doing a zero deck, then this is probably better, but I would wonder if perhaps a thicker head gasket on a block and head that have not been resurfaced/milled/deck would perhaps seal better? I would scrub the heck out of the unmilled surfaces with acetone and lacquer thinner and "MAYBE" a scotch brite pad to get them as clean as possible, then repeat again and again (with chemical resistant rubber gloves on to prevent chemicals absorbed into your skin and damaging your organs!), and then use some coppercoat type head gasket spray on install if there is any question over how perfect the gasket surface is. It is best to just have the head and block at least lightly skimmed on a head/bock milling machine. flat clean fresh even surface is really important here.

So I'm going to say we order ours in 0.8mm, 0.9mm, and 1.0mm thicknesses. Probably steer clear of 1.0mm unless your block has already been zero decked and you want minimal impact on the camshaft timing.