smoke on over run :-(

[ramon alban]

I refined the description of this method which has the merit of NOT having dodgy pipes/compressed air around and jamming the crank to prevent unwanted rotation.

Question: Can Valve Stem Oil Seals be changed without removing the cylinder head? Answer: Yes!

O Disconnect the battery so the starter cannot function.

O Remove all 8 spark plugs.

O Position a chosen piston on its compression stroke (say 10 to 15 degrees) before Top Dead Centre (TDC).

O Feed a long piece of soft rope down the plughole (don’t lose the free end of rope).

O Bring that piston towards TDC of the compression stroke by hand.

O The rope bundle, within, jams up against both inlet and exhaust valves stopping them from falling.

O Bear down on the valve spring and collet with an appropriate lever, similar to:



O Pop out the collet from the appropriate valve (both if desired).

O Fit new seal(s).

O Re-assemble spring(s) and collet(s).

O Ease back the piston away from TDC.

O Remove the rope.

O Repeat 7 times.

[ChrisJC]

I think I'd go with the Ramon Rope technique.

Chris.

[paul c]

I have used rope previously and it works well. Very easy to do.

[unstable load]

Tony,
An easy way to keep the valves in place is to use a few feet of soft rope fed into the plug hole and then turn the engine to press the rope up against the valves, tie the ratchet handle to a bit of the engine/body to hold it in place then remove the keepers from the springs.
Compressed air also works well but there is the hassle of keeping it all at TDC without rotating on its own and taking your wrist with it.

[spend]

Certainly with HC & BV engines there is FA chance of dropping the valves as long as you stick the piston near TDC.

Using compressed air to keep the valve as high as possible for the short time that you are refitting the collets does seem a lot quicker / easier to me?

[Coops]

can you buy the said tool ramon posted about?
or just make something?

[ramon alban]

The tool I pictured is

http://www.zdmak.com/wbstore/main.asp?a ... =1&LowCt=0

american, but I chose the image as a V G illustration of how it looks, for a home brew version.

alternatively google valve spring compression for other ideas.

I recall seeing one made from a bit of 1 inch angle iron with a fabricated hook to go under the rocker shaft and a strategically drilled biggish hole to push down the spring and access the collets.

[kiwicar]

I have one I made for stripping chevy heads made from a piece of 1" box section steel with a couple of holes in and an old rocker mounting ball and nut, that one is much more fancy.
Mike

[DEVONMAN]

I had a problem with smoking on overrun with my 4.6 in a Sierra. I had to modified the sump to fit the Sierra crossmember I and didn't give enough clearance for the front con rods which whipped up returning oil in the front part of the sump and drenched the underside of the front pistons. On overrun /braking oil would sit longer in the shallow part of the sump and caused mega smoking due to excess oil being whipped up to the underside of the pistons. Braking hard on down hill approaches to roundabouts always gave the worst smokescreen. Less oil in the sump didn't change things as the offending oil was drain back/returning oil.
In my case things were made worse by oil draining back from twin turbos into the front part of the sump.
Not having read all of this thread I have a couple of questions:
Have you modified the sump to suit the Capri?
Are you using a modified 3.9 sump?
Cheers Denis

[Coops]

as said in previous posts,
sd1 modded sump, (as used on the 3.9 and 3.5 engines previuos in the capri)
using sd1 baffle,
only affecting cylinders 4 and 8.

[kiwicar]

Hi Tony
It is a distinct possability, the longer throw on the crank will be bringing the rods closer to the bollom of the sump, the back part of the SD1 sump is pretty shallow from what I remember, it might be worth trying a deeper sump (or mod the one you have) before going to the misery of stripping the engine and re ringing.
Mike

[Coops]

will need to go through the sd1 windage tray before they get into the sump

and why only 2 cylinders?

[DEVONMAN]

will need to go through the sd1 windage tray before they get into the sump

and why only 2 cylinders?

Maybe longer 4.6 crank is whipping oil from the windage tray. This oil would tend to hit even no pistons first. The stiffening ribs on the tray may be very close to conrod of no 4 & 8.
Cheers Denis

[spend]

All the TVR's with 4.6 cranks, and even the stroked 5.0's use the SD1 sump, without any such problems. The only change is to pan out the shallow part at the front to clear the crank. They do have a baffle in teh main part of the sump, but I can't see that being a problem.

[DEVONMAN]

All the TVR's with 4.6 cranks, and even the stroked 5.0's use the SD1 sump, without any such problems. The only change is to pan out the shallow part at the front to clear the crank. They do have a baffle in teh main part of the sump, but I can't see that being a problem.

My 5.0 TVR lump had a 3.9 sump which as you say was modified (by TVR) at the front shallow bit to clear the rods. This surely demonstrates a need to work the sump to prevent phisical contact between the crank and sump and to minimise oil whipping. The SD1 windage plate does not extend to the front of the sump and there is no horizontal baffle in the SD1 sump like in a 3.9 sump to prevent oil surgeing towards the front during braking/slowing down. If the crank is too near the sump then I believe the whipping will occur. Also the windage plate (which was positioned to suit a 3.5 stroke) does collect oil and I believe with a 4.6 stroke the crank is likely to be very close to it and whipping the oil.
I initially raised the point because I had the same problem on a 4.6 with a 3.9 sump. Once I shaped the sump to clear the crank by just another 3mm, the problem went away. In Tony's Capri, the engine may not be tilted back as per the original design and this would exasperate the the problem.
Cheers Denis