Why dont you guys just measure the bore and measure the piston then subtract the two and divide by two and be done with it?

 

It seems like you guys are forgetting to divide by two the difference between piston size and bore to get PTW clearance. Say for example the bore is exactly 85mm and the piston is 84.8mm the difference is .2mm. Divide that by two for each side of the piston and you have .1mm ptw clearance or approx .0039" clearance.

 

After double checking I think my understanding was wrong. It is total clearance not clearance the whole way around. If so it is even easier. Measure bore subtract diameter of piston and viola!

 

I just reread toms description and it seems as though the bore guage doesnt have a measure on it just reads changes so you have to zero it out then mearure the diameter with the mic at the new "zero" to get the bore. I am not a machinist so I thought the bore guage would tell the bore not change in bore size.

 

Bore gauges need a master ring or a setting fixture to get a true size.

 

ya its confusing as **** lol. theres a tutorial on dsm tuners that makes it a bit easier to figure out.

i was scratching my head for a good while.

http://www.dsmtuners.com/forums/cyli...clearance.html

 

Do you happen to have a copy of evans-tuning build sheet?

btw. email me back if you got those that box from me

 

Gotta check for clearance of each part before you crank everything down! I found I could have got by without notching the block for the rods - but did it anyway. Overall looks like you are doing a great job though.

I'm sure your thrust clearance on the rod is likely within specs - BUT you didn't align the indicator properly to get an accurate reading. It needs to be parallel with the axis of the crank, your setup was at an angle. This will only give you a component of the actual movement - think trigonometry.

 

What do you do if you find put that you have too much thrust play? I know the factory tolerance is pretty huge, but do they make oversize thrust bearings?

 

They make a .001" oversized thrust set but that hardly helps. Not sure if something bigger exists.

 

I advised the customer that there was the potential for interference and that we could mock it all up and clearance the block accordingly. He declined this service and stated that you could "handle it".

 

Thanks Jid.

Which one did you use Jid? the one i had sucked, so i had to set it at that angle and use a different gauge. What brand were you using? i was actually using your picture on your thread for reference in trying to get it angled properly & mitsu manual, but the one i have is just cheap, junk or doesn't work.

I'd like to buy one so i can measure it the proper way.

Edit: I think i could of did it better with the rod facing outwards lol.

 

so you're saying he didnt pay $85 for the stroker clearance? how comes you told him it was good to go then and will be ready to just assemble? would of been nice to warn us that you didnt notch/clear the block for the stroker rods.

either way i don't care, i can reassemble it again within 2hrs. but id like to know why there are some scratches on the journals of the crank you supplied him that i can get my fingernail caught on..

is this acceptable or does this crank need redone?

 

He was not charged to clearance the block. There is no charge nor is there any mention of clearancing on his invoice. Did he tell you otherwise? Once again, he was told that there was a chance of interference using those parts. That was your "warning". Whether he told you that or not, he was advised and chose not to pay us to mock it up and check. Sounds like there is some communication breakdown between you and your customer.

As far as everything being ready to assemble, I told him that the parts would be in spec as far as bearing and piston to wall clearances- as was the the case. Mocking up to check rod-to-block interference is associated with assembly- something we were not paid to do. That is the responsibility of the assembler.

And for the crank, it wasn't scratched when he picked it up. I showed him all of the parts and we reviewed what was done. He approved and I sealed up the block and crank in bags and helped him load it all in his car. Apparently you didn't keep everything clean and free of grit during assembly.

 

as far as clearancing the block i can understand, since you would need to assemble it to see where to notch.. no he did not tell me anything about that.. i just assumed it was already taken care of or i wouldn't of wasted my time stretching each rod bolt to spec before turning / checking for clearance.

I definitely didn't scratch the crank.. i can assure you of that.

are you telling me that if there is a scratch on the crank that your finger nail can get stuck on when running it over it that it wont work?

i need to know this before we go wasting our time and reassemble it again. maybe im making it worse then it seems.

yes the rods, mains, ptw, etc. its all good and fine.. the only dispute i have of your work is the tiny scratches on the crank journal.. there's 2 spots i see tiny scratches that my finger nail just barely can get caught on when ran over them.

assembly was done inside a house, there is no grit or anything.. and lint free towels were used to wipe off things before bearings were assembled.

each bearing i used a new set of gloves also.. im more careful then you're thinking.