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Discussion Starter · #1 ·
Hi All ..

I have one pair of re-ground Autosprint cams with solid buckets and shims all ground in to size, cept one camshaft snapped ...!!

No engine damage as it wasn't running ... thankfully.

Now I have gone and got myself a pair of Qed 450's ground from blanks. My issue is my buckets where for re-ground cams, so they are 2mm longer with a longer centre pip to suit. Am I going to be able to use them?

I have large lathes and milling machines, even a small surface grinder if I dig it out. Was thinking I may be able to use a carbide milling bit to shorten the pip, but to what length? but then the shims are already ground so I could just shorten the pips to give the correct clearances ...??

Is the 2mm longer skirt going to give me any issues?
 

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Why all that messing around? Why re-use the buckets when that's a good way of increasing initial wear and is generally a false economy, even with copious amounts of cam' lube or anti-scuffing paste?
What I would do is use new buckets and grind the shims to the required clearances - or re-use the old buckets and then re-grind the shims to clearance.
The longer bucket skirts should not give any problems and will be more stable in the bore, anyway.
Don't forget to check for lobe clearance in the head and I assume you've already checked for clearance between the spring retainer and the valve stem seal.
 

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Discussion Starter · #4 ·
OK, bit of history ... I've had my engine for over 15yrs ... loads done to it but of note here it has SBD deep valve pocket pistons. Last year I let Philip2 re-work the head and setup a pair of Autosprint re-ground cams.

For one reason or another I took the cams out and stuck the hydros and standard cams back in and ran it like that for the last 6 mths while I set-up Jenveys and MS ecu. All went well, very pleased with it. Came to fit cams/solids and one cam snapped ...bugger !!

Now I have 450s from blanks which I'm about to see what's what with the parts I have?
 

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Well, that bit is sweet - bugger about the cam' though!
Just grind the shims to size - if given the choice, I'd make up a little support and use the surface grinder to make a nice, sweet job of it after doing most against the side of a stone.
 

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Discussion Starter · #6 ·
Thanks, I'll know more this weekend when I attack this, got a magnetic bed for the surface grinder so that should be ok.

I'm just wondering if I'll get away with just grinding my existing shims down some more as they were ground for re-profiled cams they "should" be too big for the cams I have now.

My real issue is the buckets, if they have a longer pip or not .... I've nothing to compare them to? Anyone have one they could measure up for me ...?
 

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You could stick a couple in without shims for a dummy build - that should give you a good idea, if no-one gives you that info.
 

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Discussion Starter · #8 ·
OK, sleeves rolled up .... lets attack this thing ....

Not wanting to take the head off this is what we came up with .... I had two of these valve tools so one was sacrificed for the greater good. Not petty but who cares ... lol





My TDC dead-stop tool was adapted to take an airline hose and the cylinder was presurise with the compressor .. about 100psi .. actually I didn't look !!



Look, magic, defying gravity ma .... :)




Anyway, it worked a charm, stuck a weak spring in that was found in the scrap pile, no idea where it came from but fitted perfectly.

Then took some measurements on the intake valve to piston clearances with a Dail gauge ...... exhaust valves next ... all measurements in mm.

All should be clear here, hope you can see them ..... https://docs.google.com/spreadsheet/ccc?key=0AvPZgW7Bo_x6dHlabUI3ZGFpTmR2cUtIMkZuLXZuclE
 

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That's one of the ways they do it in Yank land - but springs much easier to reach on them.
Once you've got them all charted, you can then compare them to other cam's you may be considering to see what the actual clearances are going to be.

The only thing I'd chance would be the mounting, so it picked up on both side's cap bolts as that'll make a huge difference on the loadings compared to the single side you're using - you don't want to damage them!
 

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Discussion Starter · #10 · (Edited)
It's all done now, have the valve to piston clearances for bot inlet and exhaust.

I'm writing this up on the AstraMk2 forum but will transpose it to here as well.

We had some food and went back in the garage, swapped over and did the ex valve, took about 20min all in.

https://docs.google.com/spreadsheet/ccc?key=0AvPZgW7Bo_x6dDNaRlEyVnZ5R0JvODJyZUpUQnJUd3c

A touch less clearance than the inlet side, but not a lot in it tbh.

We put it all back together with solid buckets but no shims to do some measuring. First clearance on the ex side is 0.93mm. Take off the 0.30 required clearance and we need a 0.63 shim. That's a bit thin ?

Second valve needs a 0.25mm shim .... I'm not comfortable with that TBH ... so we are now thinking of reducing the inner pip length in the buckets .... we'll see how that goes tomorrow ....
 

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Discussion Starter · #11 ·
So after calculating how much to remove from the bucket pips from my calculator here
https://docs.google.com/spreadsheet/ccc?key=0AvPZgW7Bo_x6dDNacXd0SkpEZzhxazVLLUlKUHJ0cnc

I then started on machining the buckets on the lathe ... from this



to this



Seemed to go well ... all shims installed, clearances checked and onto timing the cams






Have an issue, the cams look right, compare well to the standards in positioning, well we did use the original cam pulleys to set them and then swapped to the vernier pulleys.
However, using the degree wheel on the crank and measuring 1mm lift on opening and 1mm lift before closing we got two figures of 4 and 119 degrees.
Add these to figures together, then add 180, divide by 2, then subtract the smaller original figure and we get 147.5 cam timing at full lift .... can't be right ... it should be 108 deg for the intake cam ...

Haven't a clue what's wrong?? the cams look spot on ???
 

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Discussion Starter · #13 ·
Right ... got the cams timed in using the above video method ... from what I could find on MIG we wanted 104 intake and 108 exhaust ... we ended up with 103.5 and 108 ... close enough ...

Popped it back together and went for a quick spin with MS keeping a watching eye on the mixture .... MS increased the fuelling just about everywhere over tickover by huge amounts ... more so in the midrange ... around 20% and more in places ... about 10% at the top end ...

More fuel from MS means it's seeing more air, lots more by the look of it ... interestingly the TBs are much louder ??? dunno why. But the tappets are much quieter .. lol ... not hard really as the hydros are noisy anyway.

Oh, it goes well too ... not had much of a drive yet ... time will tell ...
 

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Discussion Starter · #14 ·
About 100 miles on the new cams now, tick-over was rough to begin with ... a few tweaks on the fueling and now she'll tickover at 500 rpm, but set to 850 now which is fine.

It's given me a few surprises I wasn't expecting, one thing is the induction noise, even on tickover, it has increased substantially even with an airbox on the TB's ... might be insulating the airbox at a later point which needed doing anyway to help with heat-soak.

Tickover is fine, I thought it might be a pig but it's not. Sorta burbles now.

Town driving is smoother ... really was not expecting that ... I can only guess as to why, the throttle is far less snappy at low revs and much nicer.

Mid range should be making more power looking at the extra fueling MS has added, but it feels a little tame 3-5k. But this may be because after 6k it really pulls much, much harder .... had me by surprise a couple of times. This is more of an increase than I was expecting TBH.

7K on and the engine is still pulling harder and harder. Like nothing I've ever driven before. My limiter is currently set at 7.5K so I can't say what happens after that ... ..... yet !!
 

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If you have qed 450 cams you should have 4,55mm lift inl and 4,03ex. at TDC and with 450V 4,19mm in and 3,175mm ex
and 450 has fully open 104deg in and 108deg ex and 450V 106deg in and 104ex.
 

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I am installing re-profiled qed motorsport 450 cams. How much are correct valve clearances? In and ex values? I am using FCP engineering solid lifters and lash caps. Hopefully setup will work together with supertech double valve springs and titanium retainers. I asked clearances from qed motorsport and given values are so small. (0,1 and 0,2mm). I used to tune stock valve clearances (like pug) with 0.2 and 0.4 values.
 
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