TRX250R.ORG
Workshop => Engine and Bottom End => Topic started by: Victork on December 18, 2015, 10:13:27 PM
-
I'll save my question and issue for last and give the story leading up first. My plan was to race in the NECC Racing last spring but my dogs and sockets rounded off leading to a tear down, I put a near new tranny in, all new seals, bearings, clutch, and another long rod crank. So I finally close in on bolting the top end on and crack a beer about a half hr ago. I bolted the top end on and push the kicker naturally to spread the oil in the cylinder and make sure nothing is bound...well the Damon piston is now hitting the freakin head! The old crank was a oem long rod and this one is one with prox rod (109). I'm guessing I'll need to have another head cut but why did the piston clear Sith the old long rod crank and not this one? I always use oem base gaskets so that's ruled out (http://forums.trx250r.org/vbulletin_imports/79_6910_2017-04-18_712.jpg)(http://forums.trx250r.org/vbulletin_imports/79_6911_2017-04-18_6534.jpg)(http://forums.trx250r.org/vbulletin_imports/79_6912_2017-04-18_5101.jpg)(http://forums.trx250r.org/vbulletin_imports/79_6913_2017-04-18_3587.jpg)(http://forums.trx250r.org/vbulletin_imports/79_6914_2017-04-18_5737.jpg)
-
possibly a stroker crank? had that happen once to a buddy he ordered a standard long rod hot rods crank but it was boxe wrong and he got a stroker crank instead. his piston may have stuck out of the cylinder more than yours hard to tell with a pic. just a thought.
-
A bigger spacer plate. They are available. Problem solved !
-
Go up to the next size spacer plate? I don't get it is the pro x a small amount longer? Oem crank the rods on doesn't look modded other than being welded on the pin
-
Is that an 85 / 86 style piston in there? how thick is the spacer plate, and how thick are the gaskets?
-
i would measure what ya got sticking out add that to the plate ya have an see what ya come up with also stick with what brand base gaskets ya got that could change things also , check esr website for spacer plate thickness needed .if not avalible they can be cut. if ya got a 4mil stroker it should be easy to figure out after measured
-
I used oem gaskets last time and also this time so it's not the gaskets. The piston is the same one it only had like 10 hrs on it. So I have oem gaskets again, and same piston/spacer plate. I honestly think the pro x rod is a small bit longer because when the cylinder was snug right before I cranked it down it wasn't bound, only when it was cranked tight
-
Spacer is approx 3/16
-
i would get ahold of esr or maybe jerry hall will chime in an have a answer . I'm not fimiliar with all the diff. rod brands length's. i would just get a measurement an go from there.
-
i dont have my 4mil motor here but my spacer is closer to 1/4
-
You have it apart that far would not be hard to measure the stroke. But if it is a stroker crank I thought there is same clearance issues that have to be addressed.
-
It's guaranteed a long rod crank. Bubba put that together for me.
-
I don't doubt it is Jon, I just don't get how the piston touches the head now. I guess I'll try a 5mm spacer and see what happens
-
I don't doubt it is Jon, I just don't get how the piston touches the head now. I guess I'll try a 5mm spacer and see what happens
The 5mm or .188" spacer are the same. You will need the 1/4" spacer. http://www.tlr-online.com/trx250r/spacer_plates
-
Payment sent let's give it a try tony
-
Will ship it out Monday. You will get it Wednesday or Thursday. I have a .312" thick spacer if need be. You did not show a pic of how your dome was cut.
-
Bam ! Problems solved
-
Hopefully squish and compression will be good we'll see
-
It should be just about where it was cause the piston should be at top dead where it was originally i would think
-
Piston now sits perfectly flush with top of cylinder using tonys 1/4 in spacer so were looking good
-
Good deal .