PDA

View Full Version : fresh top end



wllgmr
01-19-2010, 7:37 AM
Man, the thead "break in break down" has me worried that my new top end might fail when I try to start it. I also used what i think were non directional rings. They were made by haskings. The paper bag they came in had directions for installation that had photos of directional rings. For the life of me I could not find any differences in the top two rings(like the photo suggested). So Iinstalled them. I did not put any oil on any thing. The pistons and wrist pins had a light oil coating on them already. What do you guys think? I dont even have the bolts tourqed or tight. I dont want to take it apart but I wil if I should.

TroopThrowback
01-19-2010, 9:05 AM
I wish I could help you. I guess if you keep tabs on my thread it might get you some idea. As for myself, I don't think I'd go with whatever lube was on the parts. As it sat on a shelf, dust and detritus definitely adhered to those lubricants. I always carb clean all the factory stuff off and add fresh.

On that note, the two schools of thought seem to be:
1. "old school" light coat of oil on rings (work it in by rotating), piston skirt, cylinder wall, and wrist pin bushes during assembly. This is how I was taught.

2. light coat only on wrist pin bushes. All other piston and cylinder parts are dry. (tappets and blocks excluded, give them some oil) This is how I have assembled after piston failure.

The jury's still out on which is better. The old school method, the way I was taught, led to a piston failure (whether or not that was the cause of the failure remains to be seen). We will give it a second go without oil. Keep tabs on the other thread, but keep us posted on what you decide here.

wllgmr
01-19-2010, 9:34 AM
Wes, what are your thoughts? Id like to know.

Torch
01-19-2010, 9:54 AM
I wish I could help you. I guess if you keep tabs on my thread it might get you some idea. As for myself, I don't think I'd go with whatever lube was on the parts. As it sat on a shelf, dust and detritus definitely adhered to those lubricants. I always carb clean all the factory stuff off and add fresh.

On that note, the two schools of thought seem to be:
1. "old school" light coat of oil on rings (work it in by rotating), piston skirt, cylinder wall, and wrist pin bushes during assembly. This is how I was taught.

2. light coat only on wrist pin bushes. All other piston and cylinder parts are dry. (tappets and blocks excluded, give them some oil) This is how I have assembled after piston failure.

The jury's still out on which is better. The old school method, the way I was taught, led to a piston failure (whether or not that was the cause of the failure remains to be seen). We will give it a second go without oil. Keep tabs on the other thread, but keep us posted on what you decide here.

We have done tops both way with and without oil on the rings, When the rings changed several years ago we were having problems with the rings seating, we now put the rings in dry with a very light wipe of oil on the cylinder walls but I don't believe that is why your piston seized. As far as the wrist pins and cam followers and rod bearings we use "assembly lube".instead of motor oil. Motor oil has changed over the years, the AQMD took out all the additives that they said were not good for environment. and today engines have changed to much tighter tolerances and can run very thin and slick 100% synthetic oils. I am one that believe in older designed engines you should run heavier dinosaur oil with the zinc additives and in motorcycles (if you can afford it) you should run "motorcycle" oil. It is a non-detergent oil.
Wes might not agree with me but that is my 2 cents worth.

Jethro
01-19-2010, 10:12 AM
This is some info from John Healy, whom I think is probably one of the sharpest people around in regards to Triumph engine break in...

"Dry" is a relative term and used to describe an assembly technique unlike that of emptying an oil can on the rings during assembly. If, since the introduction of modern oils, you have been getting rings to consistently seat you are probably already using "Dry", or better described as "Drier" assembly.

I think I can say I have seen the inside of our machines and have been using "Drier" assembly techniques, on Vincents, British twins and Japanese bikes since introduced to the technique by Ken Tipton of MTC Engineering in about 1978.

It is important to note that the only thing that is "Dry" are the faces of the rings!

The cylinder walls which should be washed in hot-soapy water are then wiped with a lint free rag coated with a bit of brake fluid or non-detergent oil.



It is especially important to pre-lube the wrist pin, small end bushing and the wrist pin holes in the piston. Although, at first I used to leave the thrust faces of the pistons dry, I now apply a thin coat of non-detergent oil on the thrust faces of the pistons skirts.

And if you have the top end off don't forget to apply a good qiuality camshaft lube on the tappets and cam lobes!!!!"

From Jethro: I would also ask you what type of rings are these.... are they chromed, or hardened... are they cast? Plus, I honestly believe the type of oil you use is VERY important for break in. Plus, you have to have a plan for your start up and break in. You have probably already used a degree timing wheel to get your timing in the BALLPARK for start up, but you must strobe to get accurate dynamic timing set. If you are using a Boyer, then this setting is at a VERY high rpm, around 5000, and you are doing this to an engine you are starting up! I had a large fan in front of my engine blowing on it to keep temps down for the initial startup. Also, I believe that on break in you "ride it like you stole it". Although I do avoid very high rpms on break in and ALWAYS avoid lugging it in any way. Once again though I am an AMATEUR... I parrot advice and do what other professionals tell me to do... :)

http://www.bradpennracing.com/

TroopThrowback
01-19-2010, 8:35 PM
Sorry for the hijack, I didn't intend it. Are you guys all done with my thread? I want to earn more points here...