CG250 Performance Cam Installation.

[JerryHawk250]

Originally Posted by Megadan

Should one of us cheat and install a little tiny bottle of nitrous?

Oh, side note. Pushrods are indeed 6" long. Going to cut them at work today.

Oh yeah, don't pay no attention to that whistling noise. It's just an exhaust leak.

[bogieboy]

Originally Posted by Megadan

Should one of us cheat and install a little tiny bottle of nitrous?

Oh, side note. Pushrods are indeed 6" long. Going to cut them at work today.

rig up some of these somehow...https://www.amazon.com/Whip-Pack-Whi.../dp/B001MUJHKG

[duck9191]

Originally Posted by bogieboy

rig up some of these somehow...https://www.amazon.com/Whip-Pack-Whi.../dp/B001MUJHKG

thats easy, co2 atv tire inflater and a shradder valve on the intake.

[Megadan]

Originally Posted by JerryHawk250

Oh yeah, don't pay no attention to that whistling noise. It's just an exhaust leak.

It's just vortex style muffler with a built in intake silencer.

[Megadan]

Update. I got my cut to length chromoly pushrods finished at work yesterday and installed them today. I cut them about 1mm shorter than stock and that perfectly corrected my valvetrain geometry, so now my lash adjusters hit level and dead center on the tips of the valves (magic marker is great for checking this) Set my valve lash at .05mm on both valves. They are a tiny bit heavier than the stock pushrods, but not by much.

[Megadan]

Update, Part 2. As brought up previously:

Originally Posted by mtiberio

On my race Guzzi I had to tighten up valve clearances when I went to CrMo pushrods. They expand Less than Aluminum .

In anticipation of this I decided to start by setting my valve lash at the minimum spec for both valves, .05mm. On the factory pushrods the motor is usually fairly quiet, with just a faint tippety tap in the background but otherwise not very audible.

As many can attest, when you set the valves to .08-.10mm, the valve noise is more pronounced, but otherwise not bad.

This is how my motor sounds with the valve lash set at .05mm. I could try to tighten it up a little more and set them to .04mm, but I think I will leave well enough alone for now until the new pushrods get worn in a little. I personally don't mind a bit of engine clatter.

Just be prepared for this if you decide to go with chromoly pushrods.

[Megadan]

Day 2 of chromoly pushrods. As the night progressed I noticed the valve noise get progressively louder. I parked it and let it sit overnight before checking the lash again this morning. They had definitely opened up quite a bit.

This time around I have set the lash to what the Aircooled VW guys call "0" lash, which is essentially turning the lash adjuster in with your fingers until it touches the valve, but the pushrod still spins freely. Since the aluminum block and head expand more than the steel pushrod, the lash gap widens considerably as the engine gets up to temp. This is evidenced by the clatter my engine still makes even with the lash set so tight.

I rode it around for a little while and then parked it in my air conditioned garage space ( i have a vent that I can open) in order to let it cool off a bit more quickly. In about 6-8 hours I am going to check the lash gap again. Here soon everything should be bedded in nicely, but no matter what I do, the clatter will remain.

[JerryHawk250]

Originally Posted by Megadan

This time around I have set the lash to what the Aircooled VW guys call "0" lash, which is essentially turning the lash adjuster in with your fingers until it touches the valve, but the pushrod still spins freely. Since the aluminum block and head expand more than the steel pushrod, the lash gap widens considerably as the engine gets up to temp. This is evidenced by the clatter my engine still makes even with the lash set so tight.

Yep, Coming from an old VW owner that's exactly what i did. lol

[NzBrakelathes]

Originally Posted by JerryHawk250

Yep, Coming from an old VW owner that's exactly what i did. lol

Been trying for 2 years to say that these don’t need big clearances and yes noisy rappers is not good

[Megadan]

Originally Posted by NzBrakelathes

Been trying for 2 years to say that these don’t need big clearances and yes noisy rappers is not good

I don't think anybody ever disagreed with you.

The issue with the chromoly pushrods is that even at 0 lash cold, they open up quite a lot and get pretty noisy. Just the nature of the beast. To be honest I don't believe they are necessary with such a mild cam like the one I installed. I am even questioning going back to the original pushrods at this point.

[ProDigit]

Originally Posted by Megadan

I don't think anybody ever disagreed with you.

The issue with the chromoly pushrods is that even at 0 lash cold, they open up quite a lot and get pretty noisy. Just the nature of the beast. To be honest I don't believe they are necessary with such a mild cam like the one I installed. I am even questioning going back to the original pushrods at this point.

I set mine 0 hot (after a ride, with latex gloves not to burn my fingers), and I still hear them tapping. That is zero lash,finger tight.then tighten the locknut, which will tighten it even more.
Adjusting intake to 0 definitely increases low end torque, and improves cold start, but I'm not sure if it does much to top end.

Not sure how tightening the exhaust valve makes a difference yet, never tried it, as most of the time the intake valve was the one too loose.