Indian Chief stroker

[wetdog]

i have read a few times now and he appears to say that wrist pin height is some how connected to stroke , and when stroking a motor this needs to be altered , and in fact , is common practise , sorry but thats rubbish , i would agree with big boar motors , but i think he maybe out of his depth here , but i am still waiting for the evidence and will admit to being wronge if i am , i dont think im talking out of my arse as i have some experience in this area turning side valve ariels vbs into ohv motors

[Revband]

OK,
The original post asked if "anything else needed to be done other than changing the flywheels", obviously if you do this to increase the length of the stroke it is likely that the piston can hit the head, this can be avoided by using a piston with less height above the gudgeon pin, fitting a longer barrel or packing the bottom of the cylinder block, to name the most common ways.

HTH.

[rogerwilko]

The world is still flat  Wetdog! Don't go over the edge! Think of the difference between an M20 BSA and an M21, the M21 was stroked to get 600cc and they used the same barrel but the piston was the same boresize. What did they do for expediency? They raised the gudgeon pin height on the piston.

[wetdog]

o dear m20 82 by 94 mm   m21 85 by 105 mm as thought your out of your depth , keep taking the medication . is the world flat or just the top of your head .

[rogerwilko]

Pre-war 85mm,  others 82mm. Give up!

[wetdog]

sorry showing my age there but you forgot to include the date , but what you are saying ( i think ) is they moved the pin to acheve this stroke , i dont think you are giving them enough credit , they like all else out there know moving the pin has no relation to stroke . draw a little diagram and lets say swept volume 50cc now move your pin down ( on the piston ) 3mm and pack the barrel up 3mm , what is the swept volume now , please let me know the answer

[Revband]

As my Mother used to say, "there are non so blind as those who will not see".

So I will now leave you to fall out over something which you really agree on, but one can't see it.

All the best to both of you.

[wetdog]

Not heard that one , but as my old dad used to say
“ lifes like a shit sandwich , the more bread you have , the less shit you have to eat “
really has nothing to do with this post , my point is by moving the wrist pin you are not altering the stroke , its really that simple

[esometisse]

my point is by moving the wrist pin you are not altering the stroke , its really that simple

And nobody in this entire thread has ever suggested anything like that!
So wlll you please let it rest now.

[rogerwilko]

I'm tired now. Think i'll have a nap!

[wetdog]

Either the barrel height was increased to allow for longer stroke or they raised the gudgeon pin height

[esometisse]

Ok, wetdog, one last try:

Either the barrel height was increased to allow for longer stroke or they raised the gudgeon pin height

This was rogerwilkos ANSWER to OP's question: "is there anything else involved other than changing the flywheels" when stroking a motor.
So it was a known fact from the beginning that a longer stroke is achieved by putting in flywheels which have an increased crank throw. But to accomodate them and to avoid stamping holes in the heads with the piston crowns, you have to do something else: INCREASE THE BARREL HEIGHT or else RAISE THE GUDGEON PIN HEIGHT by putting in pistons with less compresson height.
That is exactly what rogerwilko suggested and nothing else.
And f you still don't get it now you'll never.
And this is the last from me in this matter.

Cheers
Andy

[wetdog]

good fun tho
i reckon on that boar stroke was incressed by @6/16 so i would  stay with existing pistons and just pack the barrel 3/16 or try looking for pistons which may not exist , which way would you go ? this is the best advice i can think of to someone trying this

[R]

Since Indian 80" heads provide a recess for the pistons in the 80" (stroked) models, consider how much of the 'discussion' here is relevant. ?

[wetdog]

i agree , but im boared , been waiting for a manxman tank to be finished for over 7 mounths now and im going mad