6m6 top with a 61X bottom ?

[Boris]

Here I am, waiting for Chucky to finish my motor. As it is the flat part of the year I'm getting kind of restless and the mind is wondering.

I have a perfectly running 650 with 175psi in each hole and a pro-tec pipe. The thing runs great, one day it was going to be my back up motor.
On the bench I have a nice set of 61X cases that were meant for a "Frankenstein" project but I don't feel like spending money to clean up my 62T 760 cylinder.

So I started thinking of making a "Mongoloid Frankenstein" by wrapping my perfectly good 650 with some 61X cases.

Anyone ever try this ?
Any gains in just a case swap ?
Is it worth the effort ?


Again, this is all due to flat water blues so if I should quit screwing up a good motor and wait for Chucky than let me know.


:smile:

 

[Matt_E]

I have a perfectly running 650

There's your answer. :biggthumpup:

Honestly, I think that you will not gain anything. The ports on the 650 are tiny (all of them). The cases aren't restricting the motor.

 

[Boris]

So no gain in the cases, huh ?

Crap !


I do have a freshly Chucky bored and ported 61X top end and a nifty Riva head that is waiting for the T-cases, b-pipe and dual 46mm intake setup .

hmm,............................


This waiting thing is killing me and I do have a 6m6 to experiment with.

 

[EvanB85]

No expert am I, but I would say a reliable protec'ed 650 is going to do just fine for now. The cases would make very minimal difference, if not a negative effect.

 

[Matt_E]

FWIW, Phill is running a 62T bottom with dual 38's and a 6M6 bored out to 717cc.

I will not be associated with that asshat project in any way.

 

[Boris]

FWIW, Phill is running a 62T bottom with dual 38's and a 6M6 bored out to 717cc.

I will not be associated with that asshat project in any way.

No love for a Mongoloid Frankenstein ????

 

[Matt_E]

Ask me who ported it and came up with the idea.

 

[Boris]

Hey misster, who ported it and whoss idea wass it ?? :18:

Does it run ?



Ill these reports that there is a big difference between the X and T cases got me thinking that's all.

It would be rather stupid to tare down a perfectly good little motor only to come up with and abortion.

Maybe I should just stick a rusty crank into those cases, dig up some dingy pistons for my 760 cylinder and see what grenades first.
Maybe we should have a blow off at Daytona.
:lmao:

 

[Phill]

Ski still need to be tuned real good....but I think it will run fine.

And matt did all the work!

 

[EvanB85]

Dual 38 6m6/62T 717. Asshat indeed. I love it. Different is cool.

 

[Matt_E]

To make matters even more interesting with this motor: When we first assembled it, we used a shaved stock 701 head to increase compression a bit.
I didn't take into consideration that the ports on the 6M6 are a bit lower, so there is more volume to compress after port closing.
That thing blew 215psi with a good battery. :haha: :haha: :haha:
Now we got a completely stock 701 head and about 180 psi.

 

[SUPERTUNE]

Boris, I hope to finish next week, I have been chugging along on getting your lower end finished! I'll ring you at the beginning of the week.
The old stuff I did back in the day was I used 6m6 cases and a 701 cylinder, hit really good with the smaller 650 intake with the smaller reeds.

 

[Boris]

Chuck, I'm not trying to rush you at all.
I'm just bored right now and have a choice,
1- destroy a perfectly good 650
2- cut my hull up and modify

Variant 1 looked like more fun with the potential for fireworks. :bananajump:


I really don't want to use that 701 top end until all the rest is done hence the Mongoloid Frankenstein.

 

[Mouthfulloflake]

Boris,

Ive asked about this before,

and the feedback I got was that it makes a difference, IF your 650 cylinder is ported, or you have other 'air moving' mods ( pipe and such)

I plan to slap my sons next engine together in a similar fashion, in fact i was porting the 650 cylinder tonight, it will go on 61x cases.

 

[Boris]

The thing does have a pipe but I doubt it has any porting done.
Could take care of that while the motor is apart.

I guess when and if I pull this thing apart I can better compare my x cylinder and the 6m6. Could try to open up the 6m6 ports to match or be close to those of the X.

Than again, I could just pull out the crank, stick it into the x cases and clean up the T cylinder.

I loved playing with LEGO when I was a kid.

 

[Matt_E]

The stock port matchup of the 6M6 cylinder is actually pretty damn good compared to the X cylinder.
But it would take quite a bit of work to get the ports the same size as an X cylinder.

 

[keefer]

Boris, I hope to finish next week, I have been chugging along on getting your lower end finished! I'll ring you at the beginning of the week.
The old stuff I did back in the day was I used 6m6 cases and a 701 cylinder, hit really good with the smaller 650 intake with the smaller reeds.

Back in the 90's there were a couple of these setups in our riding group. I built one of them, and they ran well compared to the 650. We were running 180ish compression with a good exh system and stock ignitions. They did have a good hit and we thought we were doing something trick at the time. Ahhh, the good old days.

 

[WaveDemon]

Boris, I hope to finish next week, I have been chugging along on getting your lower end finished! I'll ring you at the beginning of the week.
The old stuff I did back in the day was I used 6m6 cases and a 701 cylinder, hit really good with the smaller 650 intake with the smaller reeds.

hmm very interesting. I gots some 650's kicking around.

 

[Boris]

If this works out I foresee prices of 6m6's sky rocket.

Get them while the market is still unaware.
:smashfreakB:

 

[WaveDemon]

If this works out I foresee prices of 6m6's sky rocket.

Get them while the market is still unaware.
:smashfreakB:

I could let one go for 7 fiddy... :icon16: