MS660 Port Timings

[Nutball]

That, or JB weld a piece of aluminum in place. If nobody has tested it, it would be nice to know if JB would hold up. I figure it would most likely get blown out if it doesn't. The port material itself probably will not exceed 550F.

 

[Fruecrue]

@Brewz
Is trying this I believe with some high temp JB weld, I’m interested to hear his results. There has also recently been another product mentioned for this purpose on this site, can’t remember the name or where I read it.

 

[MustangMike]

I think I would get the standard bore Cross P+C when it goes on sale.

 

[huskihl]

View attachment 165058

Could round off that floor a little and at least make a smiley out of it

 

[drf256]

I’m a bit perplexed.

If Nutball’s 660 is freeporting a ton and has too small a squish (must admit his measuring technique is unique), why not add a gasket to it? He will gain even more exhaust duration, which I guess may be the worry?

Pretty sure the real high temp stuff is from/called “Belzonna” or something close to that. There is a new high temp aluminum braze I’ve wanted to try for exhaust ports but I haven’t found the time to do so. Welding that close warps the plating.

 

[Nutball]

Would it be a good idea to raise the exhaust even more via a gasket? I really don't know, so that's why I ask.

 

[huskihl]

Would it be a good idea to raise the exhaust even more via a gasket? I really don't know, so that's why I ask.

If you're going to keep that cylinder, I'd run it with a gasket and see what your squish is. It sounds like it'll be .025 or so which is good. I think you can still get some torque out of it, but it won't be a wide flat torque band. The cross cylinders are a little bit better if you want to get the exhaust down.

 

[Wonkydonkey]

What I was saying before, if you sort out your correct squish about 20thou. Then check your timings
If you get a correct squish you can work out if it’s better to sand or ad a gasket, yes your raising the exhust but only to get a squish. And then get timings then you can decide where to go and do what’s better with the tools you have
I for one, is not familiar with knowing what does what enough to “not start with the correct squish”. Others can just get a squish measurement and work it all out from there.
But also you need a correct tdc to get timings correct, I for one check and check another 2 or 3 times to make sure I get the same numbers.

Sounds like you need a step by step method. Not just numbers

 

[huskihl]

I've never tried adding filler inside an exhaust port. It would be nice if something would stick to the bottom

 

[Canadian farm boy]

JB weld makes an extreme heat paste. It says it’s good for something like 2400*F continuous. I haven’t tried it so I can’t say if it would work or not.

 

[Brewz]

Yes I have a development Hyway bigbore that they have changed to have really good timing but still has a hair of free port.

I got some JB high temp, good for 500F, and plan to grind down into the metal exhaust floor just down from the cylinder wall so I keep all the factory metal and plating, then put some in and grind it down to sit just higher that the end of the skirt.

I will have it beveled in a tad so the rings don’t ride on it but it should reduce any interaction between exhaust and case.

I figure the temperature at the bottom of the exhaust up against the piston will be the coolest part, it won’t be getting flamed like the exhaust roof

 

[Moparmyway]

Yes I have a development Hyway bigbore that they have changed to have really good timing but still has a hair of free port.

Some of the strongest runners that I've seen have had some free porting @ TDC ............. IMHO, run it first to see how you like it before you add anything to the exhaust port.

 

[Brewz]

Some of the strongest runners that I've seen have had some free porting @ TDC ............. IMHO, run it first to see how you like it before you add anything to the exhaust port.

Roger Copy!

 

[Funky sawman]

Freeported 66 bigbore saws that ive ran cut really good, they were just really hard to keep in tune at idle

 

[Stump Shot]

The perfect representation of Chinese garbage.

Recycle please, you realize how many beer cans that will help make?

 

[Brewz]

this bigbore times at 98/122/80, I cant wait to get it running but its gunna have to wait, my builds come second to other peoples builds and they just keep rollin in

 

[MustangMike]

Good #s, but 96/97 / 122 / 82 may be about perfect IMO!

 

[MG porting]

JB weld makes an extreme heat paste. It says it’s good for something like 2400*F continuous. I haven’t tried it so I can’t say if it would work or not.

Do you have the part number for that I'm going to be building a ms660 with the big bore and I already know I'm going to have a good amount of free port with a big gapping squish? This big bore for a 660 is more less going against what I believe in I would normally wouldn't waist my time on one but if I can get it where I feel that it's gaining and not lozing I'll give everyone step by step on what I did and ofcof cou numbers because I just don't think anyone has really tried to hard to get them to work as good as they should but that's just my opinion and sorry if my statement upset anyone it's just time to get these big bore ms660 to go good or get rid of the big bore for them once and for all guys are spending there hard earned money on them time to make it right or time for them to stop making them...........

 

[Canadian farm boy]

Do you have the part number for that I'm going to be building a ms660 with the big bore and I already know I'm going to have a good amount of free port with a big gapping squish? This big bore for a 660 is more less going against what I believe in I would normally wouldn't waist my time on one but if I can get it where I feel that it's gaining and not lozing I'll give everyone step by step on what I did and ofcof cou numbers because I just don't think anyone has really tried to hard to get them to work as good as they should but that's just my opinion and sorry if my statement upset anyone it's just time to get these big bore ms660 to go good or get rid of the big bore for them once and for all guys are spending there hard earned money on them time to make it right or time for them to stop making them...........

https://www.ebay.com/itm/J-B-Weld-3...Resistant-Metallic-Paste-/143142755836?_ul=CA

I have no idea if it will work. I’ve never tried using this stuff.

 

[cus_deluxe]

Ive got some on the way, for research...