RVF/VFR head skimming/shim question

[RVEFFF]

Hey guys. Cool forum!
I've just put my heads back on after dropping some gasket layers.
I didn't shim the carriers though, I expected it to be tighter but wasn't sure if this was safe to do. I'm assuming your just wearing them down faster, or is something likely to break in there?

So to the shims, did you just cut/drill a bunch of 0.5mm shim material to raise the whole lot up? I have 0.5mm shim material here, or I can just go racing how it is.

I guess I'm asking is it critical as in you'll break something, or will it just reduce its life to not shim it?
In advance I did search through the forum and found only one or two threads with not much info. Just wondering if your also sapping power cause the gears are so tight?
Thanks in Advance.
RVEEEEFFFFFF :D

[dobbslc]

I should think you will need to shim the gears up by the same amount you thinned out the gaskets.
Also have you checked the piston to valve clearance? As that will now be tighter too.
There's probably others things to watch out for specific to V4' s.

[RVEFFF]

Hey man, yeah checked clearance looks goods. ran it for 1 minute, (Geeze the gears were noisy). Pulled apart to check wear. All looks good, seemed to loosen up a bit, was really tight at first. I'm going to shim it but i think the biggest issue I'd face apart from shimming would be valve float at race pace. Still waiting on shim washer prices, I can use the top and bottom gasket as a template for the middle ones, but will use shim washers on the other bolts for the cam carrier and report back.

[RVEFFF]

Well, DON'T do this unless your going to shim it would be my advice.
After that minute I told you about, I tore the whole thing down to take a look at all the hardfaceing etc.
It all -LOOKED- good, however it wasn't until I started re-assembly that I noticed the cam gears appeared to be half- siezed, or just very hard to spin. Instead of free spinning easily, they were super tight, like the teeth had been jammed together. You could still spin it, but it wasn't "Normal."

Without knowing if I've put big flat-spots on those bearings, I've conseeded defeat without shims. I've got all the shims, but now need 2 new cam gears. Anyone got any before I go on an ebay hunt?
Thanks.
Rvefff!

[dobbslc]

Sounds like you've done some damage there, if anything metal looks blue it's fooked and needs replacement. Are the gear carrier's still ok not bent out of shape? Those engines or any other for that matter aren't for the inexperienced to try to tune.
Read up on Tony Scott he knows more than anyone on V4 Honda's, I think he even got new pistons designed for HRC in the RC 45 to make it work properly.
If you're tuning it to race it I would get a good standard engine and sort the suspension first.

[Neosophist]

plenty of people on here have done some skimming so dont be too put off by it but as youve found out the hard way, you MUST rebuiuild up the gap with shims, otherwise you will disintegrate your camgears.

have you tried the serarch button, serach for head skimming and you should get the results back about previous guys who have done it.

[eddyk7]

Live and learn ey James.

[RVEFFF]

So, with shimming it runs fantastic. I did buy new cam gears, the rest of it is all OK I only ran it for 20 seconds and thought ewww that sounds bad. Anyway, no damage. Woo:) And on the race track this weekend it was awesome.

Has a lot more noticeable pick up on the track, love it. Well worth the effort, and I'll probably make some of those templates in 0.5 mm steel for anyone who wants to try it on my CNC.

All I did was remove the top and bottom layer of gasket.

Now, I have encountered an issue # 2.
Its overheating, big time.
Here's what I know.
1: I didn't have a thermostat. I pulled it out. I just put it back in to test, hope that fixes it.
2: I don't think I had an airlock- was pretty good with checking that.
3: I went to 140 jets instead of 150s, I"m wondering with the extra compression I'm running way too lean now and need to go back to 150s. (I run a no-airbox race setup on my RVF).
4: Oil looks fine.

So apart from getting bigger jets and putting the thermostat back in, any other ideas.

I did note my big did run hotter when i went from 150 to 130 to test, I then went to 140s, then did the shimming. i wonder if I now just need to go back to 150s.

Any ideas would be great. I'm hoping putting in the thermostat again will also help

[Neosophist]

thermostat will make it worse.

the thermostat starts off closed to allow small circulation around the head to heat up quicker then it opens to allow coolant to go around the rad too, with it out you are always running coolant around the rads and have better flow so with no stat your biggest issue is running too cold.

i wouldnt bother putting it back in at all.

now onto the issue.

either an airlock, way too lean or both.

how did you bleed the system?

not sure on your setup but i thought the race bikes ran much bigger jets.

no local dynos about? best half hour youll spend getting the mixture right. plus with a bhp / af graph youll know where you stand.

[RVEFFF]

Hey man, definitely no airlock, the right amount of water went in, spent ages making sure it drained/filled properly during a big flush last week. Prior to a track day.

I guess running Lean i'm starting to move towards, last race I went from 150's to 130's for a windy section at different track. It got hot, but not -stupid- hot. I went back up to 140's and then dropped the gasket height/skimmed it, now its retarded hot. I just took the plugs out and they look almost plated/annealed, looks like its now way too lean. Gonna go back to 150's hope it sorts it.

Thermostat I'll keep out. Someone did say without it water pumps TOO fast through the radiator to be cooled properly, I have always had it out before though. Figured I'd ask, so cheers I"ll leave it out.
My radiators also look pretty old and grubby, lots of bent fins, buying some new ones today off ebay hopefully it helps too.
Thanks for the input so far.