Bobbybrown2018 Posted June 28, 2019 Report Share Posted June 28, 2019 I am new to building Stroker motors I'm doing a 4 mil stroker motor and I have been told both ways that the spacer plate is the best way and that redoming the heads is the best way to go can you guys explain why with one is better that would be great Quote Link to comment Share on other sites More sharing options...
97Screamer Posted June 28, 2019 Report Share Posted June 28, 2019 Make sure to never ask any more build advice from whoever told you a spacer plate is best. To properly build a stoker motor with stock cylinders you'll need to have the port timing corrected for the longer stroke in addition to having the domes cut. Just throwing a stroker crank in without porting will run like crap, might as well keep it stock. With the price of the driveline 4mil top ends have a stock set ported really isn't worth it anymore imo. Quote Link to comment Share on other sites More sharing options...
SKEETER Posted June 28, 2019 Report Share Posted June 28, 2019 Trick racing FTW 1 Quote Link to comment Share on other sites More sharing options...
ClaudeMachining Posted June 28, 2019 Report Share Posted June 28, 2019 Make sure to never ask any more build advice from whoever told you a spacer plate is best. To properly build a stoker motor with stock cylinders you'll need to have the port timing corrected for the longer stroke in addition to having the domes cut. Just throwing a stroker crank in without porting will run like crap, might as well keep it stock. With the price of the driveline 4mil top ends have a stock set ported really isn't worth it anymore imo.^^ThisEnvoyé de mon SM-G965W en utilisant Tapatalk Quote Link to comment Share on other sites More sharing options...
Bobbybrown2018 Posted June 28, 2019 Author Report Share Posted June 28, 2019 I had it ported I was told it was for a 4mil but he person the ported them said that i needed spacer plates how can i tell if i need to re port them or what i need to do Quote Link to comment Share on other sites More sharing options...
97Screamer Posted June 28, 2019 Report Share Posted June 28, 2019 You'll need to measure the port timing to be sure. You can lookup and print out a degree wheel and how to use it or buy one for a few dollars. You can also measure the height of the ports from the top of cylinder if you are reasonably certain they have never been decked. If the person said he ported it for a 4mil and to use a spacer plate I wouldn't have him do any more work on your bike. Quote Link to comment Share on other sites More sharing options...
97Screamer Posted June 28, 2019 Report Share Posted June 28, 2019 (edited) . Edited June 28, 2019 by 97Screamer Quote Link to comment Share on other sites More sharing options...
SandSlingerOR Posted June 29, 2019 Report Share Posted June 29, 2019 Good advice 97screamer. Dunno why some peeps out there say spacer plates are the way to go still. Quote Link to comment Share on other sites More sharing options...
Bobbybrown2018 Posted June 29, 2019 Author Report Share Posted June 29, 2019 Exhaust is 30mm from the top of jug and the intake is 67.5 mm to the top of the jug Quote Link to comment Share on other sites More sharing options...
SKEETER Posted June 29, 2019 Report Share Posted June 29, 2019 Transfer #s are more important than intake Quote Link to comment Share on other sites More sharing options...
AKheathen Posted July 4, 2019 Report Share Posted July 4, 2019 there's a chance that he used stroker domes, or a relieved head, and not selling those with the cylinders. if you use a spacer, stock port timings only leave enough meat for a drag port correction. decked or not, you always start by assembling and measuring deck height. (how far the edge of the piston sits below or above the head mating surface of the cylinder. measuring in mm is pretty much cheat sheet for builders or hand-me-down measurements. do yourself a favor, and pick up a cool head, but first, go look what is available for used domes. get a head that uses the most popular, if you are going to be changing things up, or if you are unsure how well your dome choice is going to work. if you don't have a micrometer setup, you can drill a hole in a piece of plywood and loosely screw it down to the cylinder and find true tdc by when the other side of the board drops 1mm or whatever on the other end and make a mark on the flywheel at this point going both ways. make a mark in the exact middle of both of those marks and you have true tdc. then you can line up your timing wheel to that mark. measure how many degrees from tdc the exhaust opens, then how many degrees till the transfer ports open. the intake boost port is a different matter altogether. Quote Link to comment Share on other sites More sharing options...
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