Charlie Boy

So I model up the cams and rocker arm. Not having access to any head means I’ve had to make quite a few guesses to angles and position of the rocker arm relative to the cam center line etc. It does seem though when I do the 1.55mm parallel move the wipe pattern always moves forward towards the valve no matter where I move things within a sensible range. I guess this makes sense as the valve and pivot move away at an angle. If I go from 0.175”(4.45mm)-0.160”(4.064mm) lash pad it recenters, if I go down to 3.7mm then it moves closer to the pivot. Anyway looks like the available 0.160” pads from MSA should work. Fingers crossed

Thanks, no chance the valve tips have been ground down, the seats would have be machined to match. They are probably set a bit deeper as the head has 2mm cam tower spacers to compensate for high compression and chain geometry. Anyone know what is easier on the cam, wipe pattern closer to the valve or to the pivot? i have new rocker arms to go with the cam.

Thanks, seems like the rocker ratio shouldn’t be used for lash pad calculations as you would always move the pivot with base circle changes which makes the 1-1.45 ratio redundant. My rockers look fairly parallel so I’m guessing I should just move the 1.55mm on the pivot and lash pad which would put me around MSA available 0.175” size. Maybe I'm missing something though.

I have modeled something up but need to measure a rocker arm when I get home. Unfortunately I'm on another continent to the car so cant get any other measurements of the valve train geometry. So other than looking at previous pictures and taking a guess it might be a bit pointless task doing that. Hopefully someone as gone through the same process and can chime in with some suggestions.

So short story is I’m replacing a slightly worn Schneider 300f cam with a Isky L490 so a fair jump down. My question is can I get close to calculating new lash pad size by the difference in base circle? 300f base circle is 27.9mm L490 base circle is 31mm cam base circle delta is 3.1mm so 1.55mm closer current lash pad size is 6mm is the following the correct calculation? 1.55x1.48 rocker ratio =2.294mm so new lash pad size of 3.7mm? is it a safe bet to go between 4.45mm to 3.7mm or do I need to go lower? Wipe pattern was even on the 300f cam I can purchase a few pad sizes just need to know the range I’m working in so if anyone more experienced can offer some advice it would be most appreciated. Charlie

I've replied to Matt's post on the Z Club forum but thought you guy's might like this article from OZ. http://www.animegame.com/cars/Oil%20Tests.pdf Ps I've been running RP for years well before I read this article.

Hey Matt I did a google search and came up with these guy's. http://www.blast-cleaning.co.uk/car_restoration.html I would stay a way from soda blasting as I think most paint manufacturers won't warrant their paints over soda blasted metal. Good to meet you. c

Yeh its that one, will send you a pm with my details.

Hi Matt, One of my cars is down in Pangbourne if you want to come over and take a look around a fully restored Z. Possibly if there's no salt on the roads over the next few weeks I could take a drive up to you as well. I would also take up Alan's offer and go over to his garage, I am sure it would be well worth the trip! Also Fourways are good guy's so you won't go wrong with their work. C