piston assembly

[missouritrailrider]

Any tips or tricks for assembling head/timing chain onto lower end? is assembly lube needed? a ring compressor? also do you only need to line up the timing marks as seen through the peep holes near cam and flywheel?

 

[ttwarrior78]

Well to get the timing chain on, you usually have to remove the flywheel, and then its pretty easy. No assembly lube is needed, just put the oil in after all assembled, and I usaully put a little oil in the top end, with the valve springs once assembled. And yes, you need a ring compressor to get the piston in. And as far as timing you line up the marks on the flywheel throught the peep hole and on the cam gear( there is a mark on the head for that)

 

[floridaredneck]

You don't absolutely need a ring compressor, it would help but its not a necessity. I always put some oil down the spark plug hole after a full rebuild.

 

[griff]

Make sure the chamber walls are absolutely CLEAN. Any grit, **** or misc contaminants will **** up the rings.

Once its clean, use some oil on your finger, and spread it around the cylinder wall. Only a super thin coat is necessary. This will prevent dry-marring on the rings.

When replacing the cam, assembly lube in the runners, and a little on the lobes, will also prevent any dry-marring.

The chain and gear dont really need anything, theyre washed in oil almost immediately on startup.

 

[jasonp]

Any tips or tricks for assembling head/timing chain onto lower end? is assembly lube needed? a ring compressor? also do you only need to line up the timing marks as seen through the peep holes near cam and flywheel?

I like to mark the top of the piston with magic marker to make sure the rings are in time or centered over the marks so when I'm putting the jug on I can watch easier. I think this step is very important to get the rings in time. You can use a hose clamp around the rings if you don't have a ring compressor. I like to use a light oil on the jug and piston and coat them before assembly as you do not want a dry startup and it does not help to seat the rings as some people think. It will just cause rapid wear and galling. Assembly lube is your friend and you can't hurt anything by putting a little to much on stuff.. I like to use that on the piston pin and rod. Also cam lobes and needle bearing and rockers get a good dose of it.
Make sure the aline the marks with the cam tensioner in place. I put the piston tdc or close and look at the T mark on the flywheel and then turn the cam pin to the top of the head so the mark is pointing up and then install the gear with the mark tords the mark on the head. I like to spin the engine around a couple times just to make sure everything alines again.
When you start the engine open the oil pressure galle plug to verifiy you got good oil pressure.. Make sure and run the engine at 2000 rpm for a little while to break the cam in... don't let it over heat and don't keep the engine at real constant rpms.
Re torque the head after warming up a couple times. Set valves and take it for a test drive.
Good luck! Have fun.

 

[missouritrailrider]

ok, i have the head still assembled on jug, i pulled it apart whole and am just replacing the piston and a thinner base gasket. it seems like a pain in the ass and i want it done so i dont have to redo it, i may just take it to the shop.........