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Potential Group Purchase - Wiseco GS650 741cc pistons

  • Thread starter Thread starter Ace07
  • Start date Start date
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...

[TABLE="class: style1, width: 1"]
[TR]
[TD="class: style6, bgcolor: #FFFFFF, align: left"]DP 630/GS






[/TD]
[TD="class: style6, bgcolor: #FFFFFF, align: left"]630cc
60mm
10.25:1
[/TD]
[TD="class: style6, bgcolor: #FFFFFF, align: left"]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
[/TD]
[/TR]
[/TABLE]
 
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.
 
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
 
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.
 
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
 
Gasket Order ASAP - INFO NEEDED from you!

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



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.
 

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Here is a photo I made for John at GasketsToGo.com for reference. The corner stud hole on this OEM Suzuki GS1100G MLS gasket is 13mm. the hole in the cylinder block is 12mm.
I figured since ours are 11mm holes on the 650 block, we should go 12mm on the gasket hole since the MLS type gasket retrofit deletes the seperate oil seal pieces and the cam chain tunnel rectangular o-ring type seal found on the 550.

GS1100G MLS type OEM gasket for reference:
attachment.php



**** WE ARE ALREADY AT 10 CONFIRMED GASKETS JUST AN HOUR OR TWO AFTER POSTING, PERHAPS WE CAN GET THIS ALL IN ONE ORDER??????

EVERYONE ELSE PLEASE CONFIRM SOON IF YOU WANT AN $80 HEAD GASKET AND NOT $120 HEAD GASKETS!!!!
 

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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.


can I please have 2 x gaskets

1 x 0.8mm and 1 x 0.9mm.

i will PayPal you $160 USD now and can pay balance if needed later.

i need mine shipped to Australia so happy to pay postage direct if needed. Can be done now if you know postage costs to Brisbane, Australia.
 
I also have a gasket that I am happy to post to John if you would like.
 
**** WE ARE ALREADY AT 11+ CONFIRMED GASKETS JUST AN HOUR OR TWO AFTER POSTING, PERHAPS WE CAN GET THIS ALL IN ONE ORDER??????

EVERYONE ELSE PLEASE CONFIRM SOON IF YOU WANT AN $80 HEAD GASKET AND NOT $120 HEAD GASKETS!!!!

Note - the $80/each gasket was just a roughly quoted price, I will let you know the final price shortly. This does not include shipping, the price per gasket is what we need to get John to manufacture them.


I SHOULD ALSO NOTE - WHEN IT COMES TIME TO SEND THE DOWNPAYMENT TO ME, MAKE SURE IT IS SENT PAYPAL "Friends and Family" so that it does not charge me a fee! I can't take a loss on spearheading this order!
 
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I would like the two I agreed to, I'm guessing one at .08mm and one at .09 or .10?
Not sure, not going to take it apart just to see what thickness I need.
 
I also just remembered that for anyone trying to do this on the cheap or needing a head gasket IMMEDIATELY, boonton_mike I believe it was also had purchased maybe 4 or so NOS Wiseco head gaskets like this one I have here:


attachment.php



I'm not sure how many Mike was keeping for himself, but I believe he bought up all of the other NOS Wiseco gaskets like this that were on ebay at the time.
I'm keeping this one just as a backup. I wondered how well this type of head gasket holds up over a few decades. I also noticed the 16mm corner oil feed stud holes, making it seem as if this gasket was also intended to take the OEM Suzuki corner oil stud seals as the original 650 gaskets did? It does not come with them like some of the Athena gasket packs do.

Perhaps someone else can answer this question better than I?



Also, I noticed that this Wiseco gasket has a bore diameter of 65,175mm as measured through the shrink wrap plastic. John recommended .5mm away from the bore on the gasket, meaning 65mm piston = 66mm gasket bore.
I need some feedback on this dimension before we get this finalized. Old Colt, do you have any feedback here?
 

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Oh my apologies Chuck. Ok I am not sure the thickness I will need. I am not even sure the entire process I need to do to get the proper measurements. Could any of you guys give me some pointers on what size I should get?
 
if your block has never been resurfaced, then any will work, thinner will give best performance. If your block has been decked substantially, you may need the thicker. you have to install the pistons and bored cylinders, and set up some spacers and aluminum washers to torque down the block on the base gasket with the pistons installed, but avoiding using the outside four corner studs or at least be very very careful with the deck surface there, as these block areas need to remain very very smooth and undamaged to seal the oil pressure in. Then you just measure how far down in the hole the piston is below the deck surface. on several pistons. dead center left to right as the pistons can rock front to rear and give inaccurate measurements.

If your piston is down in the hole .020",then I would take it to a machine shop and tell them you need about .015" (fifteen thousandths) milled off the block. Then run a .8mm or .9mm head gasket to get around .037" - .043" of total piston to head "Quench distance."
 
Yes, I definatly still want one, 0.8mm please. I can paypal a payment across as soon as you need it
thanks
Chris
 
It is common for MLS gaskets to be close to bore size where a composite gasket is larger at the cylinder. Unfortunately I can not give a good answer since I did not write down how much larger the MLS gaskets I have installed have been. I do have a few here to measure though and will do so in a few hours once the sun is up and I get in the shop.
I would also say that the manufacturer knows his product the best.
 
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