BirdDogg

So I've been doing the heads on my 3vze, and some upgrades along with it.... O/S valves and got cams done at crower.
Now I've tried very hard to make sure the machine shop had everything in time so I could have it back in time to rebuild over the weekend....

Except the machine shop calls me Friday morning and they can't adjust the valves properly because Crower ground so much off the cams that even two of the largest shims still leave too much space! (~0.045")

Now my entire weekend is a bust and I have no way to get to work Monday... Thanks!

abecedarian

So the head shop is blaming the cam guys for the shims not fitting?
How fitting.

Honestly, what's more likely:
... the cam shop grinds the cam wrong...
... the head shop installs the valves wrong....
send the cams back for verification.

If the cams are "right" and still don't work....


Honestly, I shouldn't say anything.

vital22re

iTrader: (2)

anyone grind the valve stems to cheat the adjustment?

MudHippy

All wrong. Except the OP...who's exactly where he should be. How's that?

Because...

This is what happens when you put aftermarket/performance cams in a 3VZ-E(or any other OHC engine with bucket tappets & valve lash adjustment shims for that matter). And it's been discussed here before(which is how I came to know about it).

The problem is that not all suppliers of these cams can/will also provide the special(extra thick) adjustment shims you need with them.

I've been told Colt Cams is who does. I don't have a clue where else you might find them.

abecedarian

Why should you need thicker than OEM shims?

Used cams are welded up and machined down- it is necessary for altering the ramp, duration, lift, and/or overlap if any of those are more aggressive than the stock grind. If the final base circle is different than factory grinds, then it is the cam shop's fault and then maybe they should supply corrective shims if the circle is too small. But this is problematic since only one shim should be used per bucket (no stacking) and they won't know what you need until they're installed because of variations in valve seat and face machining. This puts the responsibility for adjusting the valves squarely on the machine shop / installer.

I find it hard to believe Crower would mess up like that, but it is possible.

Like I said, send the cams back for verification they are correct. If the base circle is wrong, Crower messed up and should correct it either by reworking them or supplying the shims you need (which the machine shop should be able to tell you what sizes those are), if the base circle is correct the machine shop messed something up.

So, I was not wrong.

MudHippy

Why are extra thick shims needed?
http://www.circletrack.com/techartic...#ixzz223Z37AkM
http://www.amotion.com/tech/camtalk.html

Smaller base circle = higher lobe lift = thicker shim needed to adjust the valve clearance

BirdDogg

The cams were always suppose to still work with stock shims.

I only learned there was a problem Friday morning when the machine shop installed the cams.

I called crower but the tech who worked my cams took the day off... So next person I spoke to was Mr Crower, and he was surprised that the cams had been ground so much...he even calles my shop to confirm the remaining base circle measurements...

He has promised me they will find a solution... They spent all Friday looking for lash caps that would be large enough to work, but with no luck.

It was a definite surprise to them that these needed such a huge shim... I'm just pissed off that sitting on my hands all weekend with no truck.

BirdDogg

I always knew grinding the cams would result in needing thicker shims, but there should have only been a few thousands of an inch ground off in total!
If they even could stack two of the largest shims (3.4mm/0.1339in) then there would still be almost fifty thousands of inch (0.050in) left

I can't wait for days hoping to find lash caps... Im thinking maybe they need to start over with new cams, and get a different technician to do the work.

abecedarian

Not true. Maximum lift is determined by what the valves, springs and such will allow, and how quickly the cam can acheive such- a.k.a. the ramp.
But I will admit that a small base circle can let the cam flex a whole lot, which will affect things... a little.

I wonder about a cam grind that cant acheive ramp, lift and duration without mucking up the whole cam in the process and making it necessary to have oddball shims.
Bad, bad bad. That is laziness.





Do you ever do anything other than outsource your meanderings to someone else?

*edit-
What I meant is do you have any knowledge of your own to draw from?
You say that you've been putting the "tech" in "yotatech" since 2007, but I can't recall any time since 2008 that you've added your own personal insight.

And I'm suffering a little dismay: you didn't cite your friends over at Colt Cams here. Why is that? Doesn't suit your purpose? How convenient.

Dirt Driver

A smaller base circle allows more lobe lift without making the nose taller via welding. This is convenient when regrinding an existing cam. Some limitations necessitate it, like cam bearing diameter in pushrod V8s, but the notion that "high lift cams have a smaller base circle" is a sweeping generalization.
If the cam grinder cut on the base circle to reach a lift an/or duration goal, then it's not going to use stock shims.

Are we talking about production cams that were reground, or new cam blanks? Are there physical limitations that require a reduced base circle?

MudHippy

All regrinds for this engine AFAIK. I've never heard of anyone offering "new" high lift/duration cams for it.
I wouldn't think so. But I'm no expert when it comes to grinding cams. Maybe there is?

What I do know is...if you have 3VZ-E performance cams reground from stock they will(in all likelihood) require the use of thicker than stock shims. Since apparently, regardless of the manufacturer, the base circles will be smaller than stock. Suggesting that the practice of grinding down the base circles is quite commonplace in the process of making them.

annoyingrob

It might be necessity. They may not be able to get blank cams with a large enough diameter casting to grind the lift they want on a stock base circle (or they can't get blanks at all, and need to use stock cams), and they don't want to weld them (or maybe they cant due to the material), thus they re-grind to a smaller circle.

For what it's worth, about 6 years ago a bunch of us on SupraForums.com got Crower to develop some custom cams for Toyota 1JZ motors. The cams I got have a larger lift than stock and a larger duration, but still maintain the stock base circle so they can be used with standard shims. So, it can be done.

BirdDogg

***UPDATE***
So, latest news is that crower where is going to be in making me some custom valve lash caps.

So I suppose I'm happy about that.... I just want to get to work sooner rather than later.

BirdDogg

LOL! I am so pissed off. Crowers been telling me they are going to make the lash caps to fix the cam they over- ground.....
Every day they say "yes we are working on it... It's a top priority."
And yet nothing happens, I know it takes some time so I've been patient, but that was because I thought we had an understanding that I HAD TO HAVE CAPS IN TIME FOR THE WEEKEND, as its my days off, and I'm paying for a rental.
After they failed to finish yesterday/Thurs, I called and they say "sorry but now we have the machine all setup for ur work, and they'll be ready tomorrow/Fri."....
So you all understand why I'm so mad now, after I call this morning and the same guy who just said they're almost finished, now pretty much says "oh sorry but we are still doing more important stuff, I know ur mad and I would be too, but its gonna be Monday now, and that's really only like an 80% that we'll het to it then"

OMG! I'M CALLING THE BBB IF IT'S NOT MONDAY.

Dirt Driver

I know you're steamed, but it won't even be five business days until Tuesday.

Who handled the actual order given to Crower?

BirdDogg

I was dealing with Mr Crower himself and some other manager.... Like I said they kept putting me on the back burner, and then after arguing with them both on Friday till I was ready to blow up... They both insisted up and down that it would be impossible, there was not enough time to do the work on friday... Then I get a call 2.5hr later outta the blue from them,
"-oh yeah, ur lash caps are all ready, if u want to come get them"
sure I was very happy but they only gave me about an hours notice before they closed, and their office is basically across the street from mexico, and with Friday afternoon traffic, I still couldn't get the caps to my machine shop in time. Which was my entire goal in the first place in rushing crower. Anyway, I can't complain anymore, I'm pretty happy.

MudHippy

That's good to hear.

Just out of curiosity, how much does it cost to have Crower regrind my cams and provide me with custom bucket tappets(correct Toyota terminology for "lash caps")?

Also, what's the story with those O/S valves? I assume you went with the stainless steel 1mm O/S valves that I've seen available from engnbldr. And not the so called "oversized" valves from Enginetech(which are only .381mm O/S...if I did the math right, and not SS).

BTW...You don't have to answer either of those questions if you don't feel comfortable doing so. And thanks for sharing with us all that you have up to this point too. Now we know better what to look out for and what can be expected should we choose to go that route. Much appreciated.

MudHippy

Sorry about the valves question. I see you did go with the SS 1mm O/S.

I just haven't gotten into the habit of searching through build threads and/or previous posts to keep myself fully up to date with other people's projects.

Call me lazy...I suppose.

EDIT: You down wit OPP? Yeah you know me.

BirdDogg

Crower will do regrind at $90 per cam... But the funny thing is that they don't seem to just have a set grind they follow each time. I got a call from the technician, and he asked what I was going for, all the mods I've done on the engine, stock fuel control or not, etc. So I told him, and he said he would do "something I'd really like"....
Now, with their surprised reaction when I called with my valve adjustment problem, I assume that they normal intend not to grind so much...
They only charged me about $72 for the caps, and mine were the first of a production run, and it sounds like they are going to produce several hundred more. Mr. Crower told me that I got a deal and that the normal price is a lot more....

BirdDogg

Here are my custom "bucket tappets" or lash caps