How to hold the Camshaft from moving?

PostPost by: pharriso » Wed Apr 21, 2021 2:07 pm

I'm in the middle of changing the head with the engine in the car, what is the best way to hold the camshaft still while torqueing the camshaft sprocket bolts (25-30 LbFt). Would it be to:

1. Tension the cam chain correctly & the hold the engine in gear
2. Hold the camshaft with Mole Grips
3. Jam something through the openings in the camshaft sprocket

The workshop manual is bereft of any instructions..
Last edited by pharriso on Wed Apr 21, 2021 5:25 pm, edited 1 time in total.
Phil Harrison
1972 Elan Sprint 0260K
User avatar
pharriso
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 3186
Joined: 15 Sep 2010

PostPost by: lotusfan » Wed Apr 21, 2021 3:13 pm

Hi Phil

I did the same thing last year and I think I used a variation of 1. Certainly putting car in gear and hand brake on should work. I think I put a spanner on the crankshaft nut and jammed it against the chassis.

2 - mole gips is a no-no.

Another thought is one of the oil filter removal tools that uses a chain, the pitch would need to be the same obviously.

HTH
Mike
72 Sprint DHC
User avatar
lotusfan
Third Gear
Third Gear
 
Posts: 366
Joined: 15 Sep 2003

PostPost by: nmauduit » Wed Apr 21, 2021 3:15 pm

3) definitely : I've made an ad'hoc tool for that purpose, a bit like a pin spanner with 2 socket cap screws attached to a flat bar so that I can hold the sprocket still while applying torque. It is also quite useful to reinstall the sprockets onto the camshafts...
S4SE 36/8198
User avatar
nmauduit
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 1998
Joined: 02 Sep 2013

PostPost by: promotor » Wed Apr 21, 2021 5:09 pm

Camshaft sprocket bolts @ 45 lb ft? Isn't the figure 25-30 lb ft?
User avatar
promotor
Fourth Gear
Fourth Gear
 
Posts: 797
Joined: 16 Mar 2012

PostPost by: pharriso » Wed Apr 21, 2021 5:27 pm

promotor wrote:Camshaft sprocket bolts @ 45 lb ft? Isn't the figure 25-30 lb ft?


You are correct sir, edited my original post :oops:

OK, how do you stop the Cams rotating? :roll:
Phil Harrison
1972 Elan Sprint 0260K
User avatar
pharriso
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 3186
Joined: 15 Sep 2010

PostPost by: h20hamelan » Wed Apr 21, 2021 5:42 pm

Screen Shot 2021-04-21 at 10.39.49 AM.png
Screen Shot 2021-04-21 at 10.39.49 AM.png (124.67 KiB) Viewed 2186 times


I know this has a different mount bolt to the head, the idea is.
Born, and brought home from the hospital (no seat belt (wtf)) in a baby!
Find out where the limits are, and start from there
Love your Mother
Earth
User avatar
h20hamelan
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 1964
Joined: 25 Sep 2010

PostPost by: promotor » Wed Apr 21, 2021 6:04 pm

pharriso wrote:
promotor wrote:Camshaft sprocket bolts @ 45 lb ft? Isn't the figure 25-30 lb ft?


You are correct sir, edited my original post :oops:

OK, how do you stop the Cams rotating? :roll:


Didn't want you having an accident with a bolt in a camshaft!

Last set I torqued I just torqued them once the engine was assembled and they didn't move when on a compression stroke. That was a new engine though with very good compression.
I would think 25-30 lb ft is achievable just on compression.
You can add a bit of compression to help you with your problem by putting good sealing tape over inlet and exhaust ports - this will make the engine harder to turn over and give you a bit of help.

Otherwise passing something through the cam sprocket to lock it will help but you don't want to mark the cylinder head so it's got to be strong but not hard enough to leave an impression!
User avatar
promotor
Fourth Gear
Fourth Gear
 
Posts: 797
Joined: 16 Mar 2012

PostPost by: Mazzini » Wed Apr 21, 2021 6:37 pm

OK, how do you stop the Cams rotating? :roll:[/quote]
Otherwise passing something through the cam sprocket to lock it will help but you don't want to mark the cylinder head so it's got to be strong but not hard enough to leave an impression![/quote]

There was a fella I used to know, he would be ideal, he wasn't hard and he never made an impression :-)
User avatar
Mazzini
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 2061
Joined: 11 Dec 2010

PostPost by: RichardHawkins » Wed Apr 21, 2021 6:51 pm

Phil,

I did the same as mnauduit
RichardHawkins
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 1268
Joined: 05 Jul 2008

PostPost by: rgh0 » Wed Apr 21, 2021 8:47 pm

I use the plastic handle of a small screw driver through the sprocket hole

cheers
Rohan
User avatar
rgh0
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 8414
Joined: 22 Sep 2003

PostPost by: pharriso » Thu Apr 22, 2021 10:44 am

Thanks guys for the feedback, as suggested I jammed something through the sprocket holes. Not too difficult at just 30 LbFt :D

Onto the next operation....
Phil Harrison
1972 Elan Sprint 0260K
User avatar
pharriso
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 3186
Joined: 15 Sep 2010

PostPost by: billwill » Thu Apr 22, 2021 2:28 pm

I always remove one of the bearing caps and put a small piece of cardboard, typically cut from a cereal packet, over the cam shaft, then put the cap back on and tighten to the normal torque. This stops the camshaft rotating, but is easy to loosen off to align the timing marks.

Don't forget to remove the cardboard before starting the engine !!!
Bill Williams

36/6725 S3 Coupe OGU108E Yellow over Black.
billwill
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 4417
Joined: 19 Apr 2008

PostPost by: The Veg » Fri Apr 23, 2021 12:22 pm

3 Seemed the most obvious to me when I was working with the head, and taking precautions with the mating surfaces seemed obvious too.

Interesting about the cardboard under the cam cap- I would never have thought of that; might give it a try next time I'm in there.
1970 Elan Plus 2 (not S) 50/2036
2012 BMW R1200GS
"It just wouldn't be a complete day if I didn't forget something!" -Me
User avatar
The Veg
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 2188
Joined: 16 Nov 2015

Total Online:

Users browsing this forum: No registered users and 51 guests