a couple of engine questions

Hello,

i am rebuilding my 750 engine at the moment that i dismantled over a year ago :shock:

Now i have a couple of questions:

- in my manual there is a seal ring on the timing side of the crankshaft behind the triangular washer. I don´t have it or may be lost it. Is this seal on all engines , i could swear it was not there when i tool the crank off ? It is a very early engine.

- what is the best trick to get the pushrods into the rockers ?

- am i right that there is no position of the cam where all 4 tappets are free ?


thanks in advance for your help

Oli

twinshocker wrote;

in my manual there is a seal ring on the timing side of the crankshaft behind the triangular washer. I don´t have it or may be lost it. Is this seal on all engines , i could swear it was not there when i tool the crank off ? It is a very early engine.

Click to expand...

Yes there is one.

http://www.nortonmotors.de/ANIL/Norton% ... &Plate=001
Frame 1 No. 46

twinshocker wrote;

what is the best trick to get the pushrods into the rockers ?

Click to expand...

I personally have the engine just before TDC, offer the head down to the barrels, then locate the push rods into their respective cups, and then torque it down, checking maybe once. I locate the pushrods with some long nose pliers and have a torch to hand.

twinshocker wrote;

am i right that there is no position of the cam where all 4 tappets are free ?

Click to expand...

Yes you are right, there isn't one.

This is a 71 but I'm sure it's the same. It was like mine. Items 47 and 20 here http://www.oldbritts.com/1971_g1.html ??

I use rubber bands/elastic bands to hold the push rods up past the rockers in the head (you will need to hold the rockers up with bands as well) and sort it out after getting the head in place. Be careful and make sure the rods are seated correctly before tightening the head.

Not sure about the last one but don't think so.

Dave
69S

There is no position that will cause all the valves to be closed unless you remove one exhaust rocker and re-install it after the head is installed. I do them all that way any more because I damaged one once when I thought everthing was in place and turned the motor. Jim

Just to clarify my points in my post above.

I am assuming you are fitting the head to the engine whilst the engine is on the bench.

The push rods are put onto the followers in the barrel, and the locating is done through the rockerboxes with the torch and long nose pliers.

DogT wrote;

I use rubber bands/elastic bands to hold the push rods up past the rockers in the head (you will need to hold the rockers up with bands as well) and sort it out after getting the head in place.

Click to expand...

I personaly have never had to resort to using rubber bands, even when fitting the head to the engine when the engine is in the frame. I just push them right up into the head rotate the head and let the push rods drop down.

I'm not saying my method is any better than DogT's.....it's just the way I've done it.

twinshocker said:

- in my manual there is a seal ring on the timing side of the crankshaft behind the triangular washer.

Click to expand...

It's more like a steel washer with a lipped outer edge that faces out.

I have never considered installing a head unless being at TDC or more correctly as Jim said just slightly before TDC.
Why ?
2 lifters are on the cam base circle. The other two are at almost zero lift of overlap. Before TDC makes the more agressive intake lobe a bit down and opposite condition for exhaust. These two adjusters should be turned significantly turned out.
ALWAYS screw in the center bolt first and bring the head down to the gasket after testing the rockers are seated correctly.
It work flawlessly and without fuss every time.

To remove head do the reverse, and always disassemble at tdc, always remove the center bolt last. At this point the head pops off without fuss almost always on its own.

Thank you guys for the input !