-
Hey Guest!
British Car Forum has been supporting enthusiasts for over 25 years by providing a great place to share our love for British cars. You can support our efforts by upgrading your membership for less than the dues of most car clubs. There are some perks with a member upgrade!**Upgrade Now**
(PS: Upgraded members don't see this banner, nor will you see the Google ads that appear on the site.)
Hey - did you know if you click on the title of a thread it will take you to the first unread post since you last visited that thread?
but were afraid to ask: 
STOP!! Never post your email address in open forums. Bots can "harvest" your email! If you must share your email use a Private Message or use the 
smilie in place of the real @
Pretty Please - add it to our Events forum(s) and add to the calendar! >> 
Is this right?
- Thread starter AltaKnight
- Start date
Share this page
OP
AltaKnight
Jedi Knight
Offline
Well, I decided to test the valve timing per the manual.
So I....
1) opened the valve clearance on 11 & 12 to exactly 120 thou while on the base circle of the cam.
2) Set the engine to exactly TDC compression stroke
3) Checked the 11 & 12 valve clearance and found 12 at 25 thou and 11 (inlet)at partial valve spring compression
4) they're supposed to be equal Oh Oh!
5) drained the antifreeze and tore the the front end apart to reach the timing chain
6) set the cam to get 11 & 12 equal (18thou) while maintaining TDC
7) Had to move it 2 teeth over to get it correct
8) now partially reassembled, finish tomorrow
fingers crossed that this should improve the idle/runon situation, oh and get the vacuum up where it's supposed to be.
So I....
1) opened the valve clearance on 11 & 12 to exactly 120 thou while on the base circle of the cam.
2) Set the engine to exactly TDC compression stroke
3) Checked the 11 & 12 valve clearance and found 12 at 25 thou and 11 (inlet)at partial valve spring compression
4) they're supposed to be equal Oh Oh!
5) drained the antifreeze and tore the the front end apart to reach the timing chain
6) set the cam to get 11 & 12 equal (18thou) while maintaining TDC
7) Had to move it 2 teeth over to get it correct
8) now partially reassembled, finish tomorrow
fingers crossed that this should improve the idle/runon situation, oh and get the vacuum up where it's supposed to be.
Brosky
Great Pumpkin
Offline
<div class="ubbcode-block"><div class="ubbcode-header">Quote:]6) set the cam to get 11 & 12 equal (18thou) while maintaining TDC[/QUOTE]
Graham,
According to the TH5 printed installation sheet the camshaft checking clearance is .010" for both intake and exhaust, over the 290 duration.
However, my final valve clearance adjustments are set at .014" for the intake and .018" for the exhaust. That was a handwritten note on my spec sheet and I confirmed that with Greg at BPNW prior to the installation.
Graham,
According to the TH5 printed installation sheet the camshaft checking clearance is .010" for both intake and exhaust, over the 290 duration.
However, my final valve clearance adjustments are set at .014" for the intake and .018" for the exhaust. That was a handwritten note on my spec sheet and I confirmed that with Greg at BPNW prior to the installation.
OP
AltaKnight
Jedi Knight
Offline
Yes Paul you are correct, 14in/18out thou are the correct running clearances per the sheet I got with the cam also. The 18 thou I mentioned above is to set the lobes on the number 11 & 12 valves evenly straddling, thereby ensuring that at TDC those rear lobes are exactly evenly distributed about the TDC centreline and thus ensuring the valves are timed correctly. The 18 thou just happens to be the even clearance (on this cam) with a base circle clearance pre-set at 120 thou.
I think that's clear, at least it is to me!
I think that's clear, at least it is to me!
OP
AltaKnight
Jedi Knight
Offline
Thanks Paul.
I fired it up briefly yesterday without the rad and a bunch of other stuff installed just to see if it would run; it ran very smoothly for the 30 seconds before I shut it off; so I think I got it right this time.
It's remarkable how quickly one can tear down and reassemble something when you've just done that job a week earlier; of course I know which tools are needed and there's no rusted bolts 2nd time around!
I'll let you know what the vacuum readings are when I get it fully back together.
I fired it up briefly yesterday without the rad and a bunch of other stuff installed just to see if it would run; it ran very smoothly for the 30 seconds before I shut it off; so I think I got it right this time.
It's remarkable how quickly one can tear down and reassemble something when you've just done that job a week earlier; of course I know which tools are needed and there's no rusted bolts 2nd time around!
I'll let you know what the vacuum readings are when I get it fully back together.
OP
AltaKnight
Jedi Knight
Offline
SUCCESS!
All back together now and it runs and idles like a champ without all the shake rattle and roll. No run on either.
So that was the problem, about 1-1/2 teeth off (advanced) on the cam sprocket. Could have sworn I had it right when I first put it together but I didn't.
Now I just need to get a few more miles on it so I can open it up past 3K rpm.
Oh and vacuum is steady at 12" at idle
All back together now and it runs and idles like a champ without all the shake rattle and roll. No run on either.
So that was the problem, about 1-1/2 teeth off (advanced) on the cam sprocket. Could have sworn I had it right when I first put it together but I didn't.
Now I just need to get a few more miles on it so I can open it up past 3K rpm.
Oh and vacuum is steady at 12" at idle