Small Snag By Gti (Read 697 times)

[Gti]

So I got another P157 engine and I am very slowly and meticulously putting this thing together. I have one bolt for the engine that will not "act" (I use this term loosely for lack of a better one) WHENEVER I put a little torque of it, it pinches the crank to the point where it will not turn easily. To this point the engine is built through the point of the head being mounted and it rotates smoothly. I must add the fact that this is a P157 kit with a +4mm crank with the piston shaved. Though the engine is not timed and the head and the cam are functioning fine and there is NO hitting or binding on the top end of the engine.



There is a bolt to the left of the oil pump and cover that is missing in this pic from Bashan's build but that is the one in question. I do know this, in the other pics I have seen on his topic the bolt is hidden from v view by his hand. Suggestions?

[Gti]

That bolt doesn't matter even when I left that bolt out to see if the case would not be so tight, the case gets tight and will not rotate when the rest of the engine is put together. This is confusing!

[Alleyoop]

GTI,
The only thing I can think of that would bind it up is the CASE is tightening up against the CRANKS COUNTER weights. So what may be happening is the bearing slot is to deep on the case.
Alleyoop

[Gti]

I was thinking the same Alley. I wish I could implement the term quit but I have to conquer this thing.

[Gti]

Alley here is the strange thing. Up until this point of the b uild the engine rotates just fine.



The crank nut is tight! It is when I start to add bolts in such as the one that goes in the hole just to the left of the oil pump/cover is when the trouble begins. I am not using the aluminum gaskets I wonder if those are making a difference.

[jct842]

Get it binding or rubbing then tear it down and see if you can see marks. There is a bluing made for machinists called dye-chem that once it dries it is microns thick but takes very little to scratch. Coating the inside of the case might be the way to go, then you could see what the problem is.

[Bashan]

Before you start tightening the bolts, what kind of a gap, if any, do you have between the case halves. It just sounds like the crank is too wide. On mine, there was essentially no gap with the gasket on. If there's a real wide gap it might compress the crank bearing and freeze rotation. Just floating balloons here trying to find an answer.

[Gti]

Bashan I had an aluminum gasket between the case BUT thought about trying to add another regular gasket along with the aluminum one and it does not bind any longer. NOW the problem is the piston top not being machined enough. I have two head gaskets on it and the rocker depress the spring without the whatchamacallit screwed in at all. Another trip to the machine shop is probably going to be in order. I do not want the chain but so tight. I am running a +4 crank.

[Alleyoop]

Wait a minute how can it be depressing the Rocker Spring?? First loosen the nuts on the Rocker and backout the Adjusting studs. Bring the Piston up to Top Dead Center then put the Rocker assembly on and the CAM with the 2 holes aligned with the top of the Head put the chain on. Both rockers will be off the High Lobe of the CAM then then Tighten down the Rocker Assembly and then Adjust the Valves.
Alleyoop

[Gti]

I took your advice Alley and I think I have this right now. I was getting some binding on the top end and thought the piston was to tall. My question now is do I have tyhe right makes on the magneto to have it very close to perfect timing.





Am I close or do I need to adjust more?

[rob63]

Looks spot on to me

[Alleyoop]

Looking good my man, Does the motor turn over without binding now?
Alleyoop

[Gti]

There is ZERO binding and it turns over nicely. Here is a question. I have two head gaskets on it now. Should I try 1?

[Alleyoop]

GREAT!! No try it with the way it is and see how it runs, But first CHECK THE COMPRESSION and let us know what it is.

Also IF and when you decide to try only one gasket AGAIN be AHEAD of the game. Bring it up to TDC and THEN MARK the CAM SPROCKET and CHAIN and the FLYWHEEL WHEREEVER the TIMING CASE Pointer is pointing on the flywheel. Most of the time the Pointer is a little before the "T" MARK. But that way if you take snit off and have to take the Chain off you will line it up with the marks and not be off a tooth.
Alleyoop