Lifters Expand?

[MDK87]

Thanks Jack!

But how do I measure the piston to valve clearance?

EDIT: Googled this and found pretty good instruction on the Kelford cams website.

So, when you take your car to a performance shop and ask them to dial in the cams, they play around with cam timing to achieve the closest to desired output, but do they check the piston to valve clearance every time they make adjustments to the cam timing? I don't think they do? Because it involves changing the valve spring and installing a solid lifter...

I have a degreeing kit with everything I need except for a solid lifter.
I'm very confused though, and I don't like giving up but I'm thinking of using the stock cam gears because this stuff is just going way over my head lol

 

[blackvr]

AAhh , theres a reason for everything and I'm glad you found it ! Re piston to valve clearance. The critical area is the region around 5* around TDC. If I am am playing with cam timing on the dyno, I try and work out just how much clearance there is on the extremities of the vernier gear adjustment. You can get a rough idea by simply "levering ' the valve down in situ and measuring the clearance as the above poster has explained. To do it properly really needs a solid lifter..., as the HLA will compress a little with no oil pressure present.

 

[brisvr4]

Is this for a 63 Mo? I have a pair of solid lifters if you need them.

 

[MDK87]

AAhh , theres a reason for everything and I'm glad you found it ! Re piston to valve clearance. The critical area is the region around 5* around TDC. If I am am playing with cam timing on the dyno, I try and work out just how much clearance there is on the extremities of the vernier gear adjustment. You can get a rough idea by simply "levering ' the valve down in situ and measuring the clearance as the above poster has explained. To do it properly really needs a solid lifter..., as the HLA will compress a little with no oil pressure present.

I tried doing that exact same thing yesterday Mike! Taking the sliders to each end of the spectrum for intake and exhaust cam and checking for collision between the valve and piston. I was hoping to find that point, and then mark down the phase angle reading minus a couple degrees and just not venture past that point.
Then I realised what I was doing was worthless without solid lifters.
I would change the spring as well (because I have the checker springs) but on a CA18 it is very difficult to take the spring out once the head is on as it's in a bore and I only have (borrowed from JETGSR) the tool for removing valves with head off.

I am worried however that by using this method I will bend a valve again.
I think the only solution is to find a way to install the checker spring..

Is this for a 63 Mo? I have a pair of solid lifters if you need them.

Hey Tim, this is for a CA18. Did you make the solid lifters yourself? I have spare HLA's I could mess around with..
I guess all I'd have to do is depress the (empty) lifter and measure between the lifter head and base circle of the cam and find something to pack it with to that exact thickness.

It might be hard for you guys to envisage what I'm saying given it is different to a 4G63 so here's a pic of a CA18 head.

 

[4piknup]

Oh, you have no rockers. So cam lift is the same as valve lift.
So you don't really need the cams in to measure, but you will need to be able to depress the valves, and measure the depression.


How about you modify a lifter to give you 0 lash + your requested clearance. So make 1 with -2mm lash for exhaust (or only tighten the cam caps that far). And then turn engine gently for clearance.

But I reckon you will have to be close to valve bind

 

[MDK87]

I was pretty worried (well you guys scared me ) about valve collision so I made this thing up to take the valve springs out with the head on and I welded myself up some solid lifters set to zero lash (well +/- ~0.05mm). I measured with vernier micrometer but still got a small clearance when installed using a feeler guage of 0.06mm thickness.
I was pretty happy with how my tool worked! But I couldn't imagine doing 16 of them like this... >.<
I'll get back to you guys soon with piston to valves clearances so perhaps you can help me make sense of it all. Measuring every 2deg from 15deg BTDC on the exhaust and 15deg ATDC on the intake.

 

[MDK87]

And the reason for the coach head bolt was, it's all I could get my hands on Saturday afternoon! Lol
Actually, I've already measured the piston to valve clearances (but I don't have them with me atm) and have re-assembled and re-installed the engine into the car.
After checking the piston to valve clearance by pushing the valves down by hand (using the checker springs), I set my vernier cam gears to full scale which was about 14-15deg. I advanced the intake and retarded the exhaust. Then I turned the engine over and there were no collisions. So I will just 'tune' them on the dyno when it's running and I won't venture past 10deg either way at the camshaft. Is this a sound theory?

I wanted to check the centreline of the cams and install them straight up, however I couldn't figure out how to use the dial indicator with the cams in (there was no free space on the lifter head to mount the dial pointer onto... >.<
So I just set the cam gears to 0 and as stated before, will 'tune' them to provide the engine output I like best.