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Post by aeroxbud on Sept 4, 2019 19:22:21 GMT -5
I would be giving up on this cylinder by now. NOT an option. NEVER give up!  No retreat. No surrender. 😁 |
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Post by pitobread on Sept 4, 2019 20:35:59 GMT -5
They are M7x1.0 stock on all of the hor Minas that I've had. M8 then? |
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Post by ryan_ott on Sept 4, 2019 20:55:06 GMT -5
Last ditch effort... are you using any alignment dowels between the cylinder and head? If not can you drill for them? It may also be worth while to stuff an o-ring in the cylinder and head prior to assembly for a sandwich - o-ring, dowel, o-ring.
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Post by supascoot on Sept 5, 2019 4:08:07 GMT -5
We do a lot of annealing on 6 cylinder copper head gaskets for historic race cars and have had far better success by heating them up cherry red and dumping them into water usually do them on something like a oven rack so they can be dropped straight down into the water. It also makes clean up easier as a lot of the scale comes off that way. And as for sealant the ONLY one we have had success with is dow Corning 532... I know seems odd but I think some of the more engine based sealants don't spread out as easily. And believe me we tried anything we could think of. Copper spray didn't work very well either. We have virtually no head gasket issues now and that's even with engines down to .100" between bores. Oh and the gasket will be deformed after quenching but dont be tempted to flatten it just de scale, clean and apply sealer and bolt head on. The less bending and moving of the gasket, the less chance it has to start work hardening. Randall
Oh and one other thing we do and may be of some benefit to you. On one side of the engines we deal with is the pushrod area so oil area... we machine an extra .002-.003 off that side to allow of the clamping force to be put on the combustion areas and along that edge we use an engine based sealant. So perhaps a little metal removal around the perimeter may be of benefit to you to provide more of the available clamping force for the combustion area and use a different sealant out there. You could try bigger studs as been sugested BUT sometimes that can create more problems as when the engine heats and expands the studs can't stretch and return as the engine cools so they will keep coming loose, they will just stay stretched. Where as the 7mm ones are more likely to stretch and return providing they are not over torqued.
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Post by 90GTVert on Sept 5, 2019 7:19:14 GMT -5
They are M7x1.0 stock on all of the hor Minas that I've had. M8 then? It would certainly physically fit, but there wouldn't be much meat left around them in the cases so I'm not sure if they'd really take more torque. Last ditch effort... are you using any alignment dowels between the cylinder and head? If not can you drill for them? It may also be worth while to stuff an o-ring in the cylinder and head prior to assembly for a sandwich - o-ring, dowel, o-ring. I'm not using dowels. Could drill. Don't know if I will or not. We do a lot of annealing on 6 cylinder copper head gaskets for historic race cars and have had far better success by heating them up cherry red and dumping them into water usually do them on something like a oven rack so they can be dropped straight down into the water. It also makes clean up easier as a lot of the scale comes off that way. And as for sealant the ONLY one we have had success with is dow Corning 532... I know seems odd but I think some of the more engine based sealants don't spread out as easily. And believe me we tried anything we could think of. Copper spray didn't work very well either. We have virtually no head gasket issues now and that's even with engines down to .100" between bores. Oh and the gasket will be deformed after quenching but dont be tempted to flatten it just de scale, clean and apply sealer and bolt head on. The less bending and moving of the gasket, the less chance it has to start work hardening. Randall Oh and one other thing we do and may be of some benefit to you. On one side of the engines we deal with is the pushrod area so oil area... we machine an extra .002-.003 off that side to allow of the clamping force to be put on the combustion areas and along that edge we use an engine based sealant. So perhaps a little metal removal around the perimeter may be of benefit to you to provide more of the available clamping force for the combustion area and use a different sealant out there. You could try bigger studs as been sugested BUT sometimes that can create more problems as when the engine heats and expands the studs can't stretch and return as the engine cools so they will keep coming loose, they will just stay stretched. Where as the 7mm ones are more likely to stretch and return providing they are not over torqued. Is that a typo and you meant 732? I don't see a 532. 732 info... Product : amzn.to/2Lm16oHData Sheet : consumer.dow.com/en-us/document-viewer.html?ramdomVar=4105221251865626983&docPath=/content/dam/dcc/documents/en-us/productdatasheet/95/95-10/95-1059-dowsil-732-multi-purpose-sealant.pdf |
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Post by supascoot on Sept 5, 2019 7:28:11 GMT -5
It would certainly physically fit, but there wouldn't be much meat left around them in the cases so I'm not sure if they'd really take more torque. Last ditch effort... are you using any alignment dowels between the cylinder and head? If not can you drill for them? It may also be worth while to stuff an o-ring in the cylinder and head prior to assembly for a sandwich - o-ring, dowel, o-ring. I'm not using dowels. Could drill. Don't know if I will or not. We do a lot of annealing on 6 cylinder copper head gaskets for historic race cars and have had far better success by heating them up cherry red and dumping them into water usually do them on something like a oven rack so they can be dropped straight down into the water. It also makes clean up easier as a lot of the scale comes off that way. And as for sealant the ONLY one we have had success with is dow Corning 532... I know seems odd but I think some of the more engine based sealants don't spread out as easily. And believe me we tried anything we could think of. Copper spray didn't work very well either. We have virtually no head gasket issues now and that's even with engines down to .100" between bores. Oh and the gasket will be deformed after quenching but dont be tempted to flatten it just de scale, clean and apply sealer and bolt head on. The less bending and moving of the gasket, the less chance it has to start work hardening. Randall Oh and one other thing we do and may be of some benefit to you. On one side of the engines we deal with is the pushrod area so oil area... we machine an extra .002-.003 off that side to allow of the clamping force to be put on the combustion areas and along that edge we use an engine based sealant. So perhaps a little metal removal around the perimeter may be of benefit to you to provide more of the available clamping force for the combustion area and use a different sealant out there. You could try bigger studs as been sugested BUT sometimes that can create more problems as when the engine heats and expands the studs can't stretch and return as the engine cools so they will keep coming loose, they will just stay stretched. Where as the 7mm ones are more likely to stretch and return providing they are not over torqued. Is that a typo and you meant 732? I don't see a 532. 732 info... Product : amzn.to/2Lm16oHData Sheet : consumer.dow.com/en-us/document-viewer.html?ramdomVar=4105221251865626983&docPath=/content/dam/dcc/documents/en-us/productdatasheet/95/95-10/95-1059-dowsil-732-multi-purpose-sealant.pdfYes sorry 732 the clear one |
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Post by 90GTVert on Sept 5, 2019 11:37:58 GMT -5
With the rumor circulating at times about the Top Performance crank being out of true out of the box, I had to check this one. I thought it was gonna be hammer time, but I can't touch this. These indicators have 0.0005" graduations and it didn't even move halfway to one of them. Looks like it did on one in the pic, but that's just my zeroing error.  |
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Post by 90GTVert on Sept 5, 2019 22:14:52 GMT -5
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Post by PIG on Sept 6, 2019 8:54:33 GMT -5
Big power is just around the corner! I’ve been waiting years for this to finally happen.
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Post by 90GTVert on Sept 6, 2019 14:17:03 GMT -5
Big power is just around the corner! I’ve been waiting years for this to finally happen. This is going to be so disappointing to anyone with high hopes. Just from looking around lately : 70cc Sport : 6-9HP (stock-20mm carb, sport/midrace pipe) 70cc Polini Corsa : 9-11HP (17.5-21mm carb, midrace/race pipe) 100cc Apex ATV : 12HP (24mm carb, factory tuned pipe) 86cc TPR : 20-22HP (24-28mm carb, hyper-racing exhaust, inner rotor) Not really sure where where the 103cc w/21mmm, Peace Pipe comes in. At least in the range of the Corsa to ATV. But now, where does the 86cc TPR come in with a 21mm carb, Peace Pipe, stock ignition? Could run like crap from mismatching and never be faster than the TaoTao. Definitely not 20-22HP. Most likely melted in short order. I have been considering putting the big reeds setup from the KX on here with a 24mm or 25mm carb. It wouldn't be the flat slide that everyone else goes with though. It would be a PHBL that I have. That failed miserably and I couldn't get it in tune on the 103cc, but then who knows if that could be related to the ignition issues that perhaps have been building for a long time. Just sayin', nobody get too excited. |
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Post by 190mech on Sept 6, 2019 17:33:46 GMT -5
The TPR jug has decent(not wild)port timing numbers that work well in off road applications,so I'd think the setup you are thinking about should do fine..A 24 to 28 'roundie' still gets fuel mixture into where it needs to be,flat slides are the NOW thing,but gas dynamics are still the same!If the Peace Pipe fits,it should do well also for your use..A flat line 15 degree ignition is fine too!  |
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mattyslimz
Scoot Enthusiast
Posts: 222
Location: Northern Virginia
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Post by mattyslimz on Sept 6, 2019 18:54:49 GMT -5
The TPR jug has decent(not wild)port timing numbers that work well in off road applications flat slides are the NOW thing I do see on Instagram all the overseas Supermoto full-size MX street legal bikes running this cylinder. They’re a pretty big bike, it’s like a CR125 frame and than there’s a whole bunch of empty space with an 86cc bore in between. I’m not sure what kinda bikes they are, maybe Derbi, Aprilia? Anyways, if they’re pushing that big thing around and are kitted on so many bikes the folks must be happy with its torque/power. Flatsides are the ‘in thing’ now? Who knew!? Lol but I still can’t tune mine for -ish, will give it a go this weekend. Sounds like Brent could use my 24mm S6 R/T carb and I’d be better suited with his style 21mm. |
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Post by ryan_ott on Sept 6, 2019 20:14:39 GMT -5
mattyslimz The bikes your referring to are likely powered my the minarelli AM6, good motor even in stock form capable of 65mph, yes unfair. Aprilia RS50 has that engine. I had one 😥
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Post by 90GTVert on Sept 6, 2019 21:22:58 GMT -5
A flat line 15 degree ignition is fine too! That's something I meant to mention here. The manual states 20° ignition timing. The stuff I use retards about 3-5° from idle to 10,000RPM. I figured I'd just set it to 20° at idle most likely, and it would back down to 15-17° at 10,000RPM. Should I be more conservative? I don't really know what kind of curves the high dollar ignitions for hyper race kits use and haven't got around to looking yet. |
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Post by 90GTVert on Sept 6, 2019 21:38:47 GMT -5
Spent some time on port matching and trenching today.     The trenches aren't as aggressive as what's on the 103. That seems kinda bass ackwards to have the least aggressive porting on the most aggressive engine I've ever built. My reasoning is that : 1) It prob doesn't make that much difference. 2) The really aggressive trenching is more likely to have cases crack and leak and I will prob have enough issues with the aluminum kit without introducing the higher case leak risk as well. |
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