Potential Group Purchase - Wiseco GS650 741cc pistons

[Chuck78]

I one gasket that I used the smallest size of Dremel sanding drums to adjust came out very well, but it took me 35 minutes of careful testing sanding and cleaning & repeating, & now I still have a gasket that I need to take the rivets out of and clean the layers surgically clean and free of abrasive and metal dust, and reassemble...
I definitely considered doing this, but that would be one very long and frustrating day for something that we all shelled out collectively over $1,200 for 15 of...

I think I'm going to send most of them back but keep a few here even if I have to buy a few more, just so I have a few on hand. With instructions for replacements to be expedited substantially. Heck at this point, to further speed things up, I would just as soon purchase the entire lot all over again on my credit card just to get them moving faster...


On the flip side, I cut the 36 year-old shrink-wrap off of the New Old Stock Wiseco branded composite 65mm big bore gasket, and test fit it. I would have to say, although the alignment dowels were properly spaced on the Wiseco NOS gasket, our gaskets are a much more precise fit on the bores (& I'd say they arent perfect at that, the Wiseco's are just far worse). The 36 yr old Wiseco gasket had a lot of overhanging areas with the gasket well into the cylinder, and out of round portions of the compression ring area of the gaskets...



As far as shipping, they were sent TNT Freight internationally, then FedEx. The customs bill arrived here despite address and name being very incorrect, but I have yet to pay it. Perhaps when I send it back, I will state that it is a merchandise return and use the erroneous name it was sent under initially

 

[Chuck78]

I think most of the issue resulted from a bad digital scan of the OEM gasket (good thing I did not send the Wiseco NOS unit! It is way less precise on the compression/fire rings around the bores!) & failure to compare the first new manufactured gasket with the OEM sample gasket template, & also failure for them to send me a test gasket to verify all is good. He did initially say that he would make one, and send it to me for verification and testing. But instead I just got told the entire batch was done and on the way...


The 2 custom Volkswagen diesel MLS gaskets that I have purchased from them did not have any of these issues, so I am scratching my head even more as to why these were not up to my standards.

 

[frankenwabbit]

yeah.. chuck...you shouldn't have to spend 35+ min or so on them gaskets (though we appreciate the effort) .....they mucked it up, they should be fixin it.

 

[Chuck78]

I'm keeping the one that I trimmed, just in case anyone needs one immediately, but the rest are being shipped back. The one that I "adjusted" still needs the rivets removed and the metal shavings and abrasives dust blown out of it, and re-riveted.
I tried to ship the batch back Saturday but got some serious flack from the postal employees for coming in at 10 minutes before closing and needing to fill out customs forms, so they told me sorry here's a custons form, come back another day with this already filled out and we can ship it for you...

John told me he can turn them around in 7 days once they arrive there. I'm guessing they'll just make a new batch.

If they are making a new batch, I'll just have the 2 non-USA orders shipped straight to you two guys in Australia and the UK. If those need shipped back, I will let you know. I am assuming you guys received those two orders already. The rest of them arrived here a few weeks ago when I was seriously ill, and I hadn't gotten to do anything with them until the past week or so.










I'm really looking forward to building up both this 740cc GS550, & the 489cc GS425. It's still the off-season, but although I hear/see bikes all over town on these 45-65 degree days, the amount of massive potholes on the highways in particular terrify me, especially in low light times or heavier traffic, so I haven't been on a bike since late December. It was a rough winter of freezing rain and deep freezes, and took a major toll on the roads with previously cracked up pavement...

Planning a serious Appalachian twisties trip for a small group of friends has got me really thinking about wanting to ride a lighter middleweight 4 cyl (GS550/650-740cc) or the 325lb barebones F500 racer build GS425 twin...
Thinking about slinging around even my substantially lightened 467 lb gs750 "heavyweight 4 cylinder" into all these tight turns at this point of being off bikes for months has me really leaning towards the lighter options...my buddy Dave (drey6) has a GS550 project bike (never ridden), had a CB750 DOHC, and a Ninja 600 or 650 ('86), & yet he has only the highest praises for the GS450 that "he got for his fiance..." and reinforces what the previous owner said about it - "Really fast for a 450..."
He really digs the lighter bikes, especially for tagging along chasing me through all the Appalachian SE Ohio twisties that are 45 minutes from our doorsteps...

So I'm very anxious to get my own GS550 on the road in my typical heavily performance-modified form...
Riding the Wiseco 610cc GS550 last year which I rebuilt for a friend was even a real awesome eye opener for me vs my bigger 750 on a diet... I was scraping it in turns just blasting around my neighborhood on test rides, effortlessly!
I do very well on the 750 in the twisties, but it's one of those comparisons where you just don't realize that things can get even better until you get some firsthand experience, & are then very pleasantly surprised!

 

[frankenwabbit]

quick questioj for those who have bored out their cylinders...

what was your piston to wall clearance set to? to what the wiseco box said?

 

[Chuck78]

That's what mine are set to, .0021" per Wiseco.
I have read of a very well regarded KZ/Z1 shop varying the clearances between the inner 2 cylinders and the outside two cylinders due to the inner 2 running a bit hotter, but I've never talked to anyone who endorses this. I don't hear Rapid Ray discuss this, so I figure all 4 to the same clearances on my GS's sounds good to me.

I checked the tracking (CH038006440US) after emailing John @ gasketstogo.com, they still haven't made it there but are almost on their doorstep. I expressed kindly how we need to have them ready to fix this issue and get us a batch of gaskets with proper dowell alignment ASAP but not with rushed quality control...
Apologies for the delay. I wish Cometic would have interested in doing this project for us, but the quantity that would have been required to get their interest would be astronomical for our scope. This left me wondering how difficult it would be to custom cut a copper head gasket... Probably not the best long term solution there though, I believe those are generally more for race engines and don't seal oil passages that well if I recall correctly.

 

[frankenwabbit]

my enginerd buddy and the machinist were thinking of giving it a lil extra wiggle room .0023 to .0024 and felt the tolerance might be too tight at .0021.....heat tolerance being air/oil cooled and all. factory cast piston to wall clearance is .0020 .

considering the machinist has much more experience at building motors than I do, i just nodded my head and said as long as it works well.


*slowly raising my engine building learning curve*

 

[Chuck78]

my enginerd buddy and the machinist were thinking of giving it a lil extra wiggle room .0023 to .0024 and felt the tolerance might be too tight at .0021.....heat tolerance being air/oil cooled and all. factory cast piston to wall clearance is .0020 .

considering the machinist has much more experience at building motors than I do, i just nodded my head and said as long as it works well.


*slowly raising my engine building learning curve*

MTC Engineering told me to go .00075" on these 1980's NOS pistons I got from them, and all of their other GS 10.5:1 compression pistons...
So when Wiseco tells us .0021", I'll believe that more than I believe MTC especially after Ray said he is giving them a little bit extra room because that is absurdly tight (the old NOS MTC Pistons).

I'll trust Wiseco's spec because they are the highly educated engineers who formulated the metalurgy recipe for these based on decades of experience. That's my opinion/take on it.

 

[frankenwabbit]

hey chuck....has gasketstogo finished up the gaskets?

 

[Old Colt]

I have an update on the gasket order.
I have been working with John whom makes the Gaskets.
I spent the time to manually measure the bored out cylinder block for my project and generate an accurate drawing for John to work with. The first drawing reached him this past Sunday evening our times, this being Monday morning for him. It took a few volleys of emails sending files to him till my drawings were fully compatible with his drawing software. Basically my system's output of the text size when working in metric units was the issue.
At the end of that session he stated he would get back to me Wednesday which he just did.
He states the drawing is good and he is ready to make the test gasket.

I have requested he sends the test gasket directly to me since I am responsible for the accuracy of this batch.
Once I have received and checked the accuracy of one gasket, make corrections if needed then this gasket order can proceed again.
The terms of the continuation of this project will be between Chuck and John.
I have just stepped in to do what I can to make this project successful.

 

[Old Colt]

I just got a note from John the test gasket from my CAD drawing will be on it's way to me.
More once it arrives.

 

[frankenwabbit]

thanks for the update!

 

[Old Colt]

The test gasket arrived, it is almost right. For some reason nether John at Gaskets to Go nor I understand one of the end dowel holes was stamped with an 8mm hole rather than the 10mm it should be. He is checking into how or why this happened. More later.

 

[Ace07]

Thanks for the update.

 

[Old Colt]

Maybe, just maybe we have a good gasket coming our way.
The previous test gasket I got was 366.5mm between the outer dowel pin holes. The cylinder blocks I measured and drew up were 368mm. I would jump to conclusion, but with only one good leg I can not jump, I expect the gaskets Chuck got may have been the same 366ish dimension.
I asked John today when I got the tracking number to confirm the dimension which he did.
So we might just have the tooling to make usable gaskets, 10 or so days we should know.

 

[Chuck78]

GREAT NEWS!
Yes, the original order had the left to right bore spacing and alignment dowell spacing distorted a bit, but the other big concern that I had was uniformity throughout all the layers at the cylinder bore edges. If the thinner outer layers are not stacked evenly, I was afraid of these thin, overhanging, uncompressed portions of the gasket potentially causing hot spots which wpuld risk preignition detonation.
With the Cometic CFM-20 composite gaskets, they have a roll formed compression ring that would be design be immune to this layered phenomenon.

A properly/uniformly stacked Embossed MLS gasket would be the better choice IF we can get that out of the 3rd (4th?) attempt.

My apologies for the time frame once again. I have not asked for a refund yet until we get this new gasket from John to Charlie, and I talk to Charlie about his observations and opinions after he receives the gasket made from his CAD drawings.

Worst case is a week out at the time of refusal/approval if we decline on the MLS batch re-make.

Thanks Charlie & everyone

 

[Old Colt]

The first test gasket had good alignment for each layer. The big issue was the wrong width between dowel holes which if one end was fitted it shifter all the bore holes over enough to be a problem. This was masked to me at first since for some reason one dowel hole was punched the proper 11mm while the other was 8mm. This hid the true problem of the C-C spacing being wrong. I am glad I chased down that measurement, I am weak on digitally measuring over 300mm so I had to spend some time to both confirm my drawing and that the tooling was made wrong.
A secondary issue was the head stud holes were a bit small, 7.8mm. This would not be an operational issue but would require care installing and removing the gasket down over the threads of the studs. Someone in a rush could bungle something up. The stud holes in the head are 8.25ish so I requested these holes to be punched a bit larger.

 

[Old Colt]

Newest gasket has arrived and is good to use.
It has one minor issue in that somehow the end dowel holes were stamped a bit small so they are tighter than they should be. That issue was relayed back to John to be corrected.
But I would say these are now a usable gasket.
Fresh in it's package


I forgot I can only post one picture at a time, why this is I have no clue.

 

[Old Colt]

And now it seems I can not post a simple picture on it's own

 

[frankenwabbit]

as sheriff roscoe p coltrane once said....good news good news!