FurryOnTheInside
In Memoriam
Mine's at 0.55mm and working great so far. I might try increasing it to .8 sometime, but just to see.
I read the minimum is .5
I read the minimum is .5
Port timing
- Thread starter Stoneman
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Street Ryderz
Well-Known Member
Yes half a mm is pretty tight with little room for wear.
out of interest how do you work your blow down out? i mean how do you judge it or do you just grind a bit and see how it goes?
are you using and type of calculations?
whats you basics of porting a motor?
Street Ryderz
Well-Known Member
I use a combination of the lambretta port timming calc on line to play around with the numbers and see if it looks right first then I use a degree wheel i found online that I printed out an stuck on some aluminum and physicaly check the port opening degrees of each and do the math.For the blow down it's the amount of degrees between the exhaust port opening and the transfer opening,The problem with these engines in that area are that you really cant raise the transfer with out reducing blow down duration and to get the duration back you have to raise the exhaust witch start shifting the power range.Simply put this means that if you want to run in a higher rpm range and for go bottom end go for it but if you want torque and drivabilty then it's not recomended to raise the transfers.The next part of that is if there are fewer degrees between exhaust opening and the transfer and your using a real tunned pipe the scavaging can be optimized as the exiting exhaust pressure is higher at the point of transfer opening it helps pull the next charge up and out into the cylinder and out the exhaust port with the pressure wave and thats great but until the engine is at that perfect rpm and resonance point of the pressure waves(on the pipe) it's hurting the over all performance in that the cylinder is not receiving a full charge of a/f mix to make power with so the happy meddium has to be found and everyone has their own preferance as to whats best lol.Here's the wheel I use it's perfect for what we need to do and once you have it you can reprint for ever LOL admittedly mine gets unreadable after awhile so I just clean it of and stick a new one on.
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Yeah cool, I like the measuring atm but that may change in time
I would like to see some good info shared with members for everyone to learn
It’s not black magic if you know what I mean
My blow down I have it set at should work pretty well but yet to test
Admittedly I’m in the early stage of the learning process but really enjoy seeing a community sharing tricks and tips like your back cut on the transfer ports
I would like to see some good info shared with members for everyone to learn
It’s not black magic if you know what I mean
My blow down I have it set at should work pretty well but yet to test
Admittedly I’m in the early stage of the learning process but really enjoy seeing a community sharing tricks and tips like your back cut on the transfer ports
gary55
Well-Known Member
I'd like to see the back cut as well with a little narrative. I always steer clear of that side.
machanic
Active Member
Stoneman, how did you access the spreadsheet for balancing, I tried at resources and got the ERROR404 site not found.
I purchased it through jaguars website
It was a PayPal payment and he emailed the copy of the excel sheet
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