sump catching steering rack

[rac]

Hi to all the RV8 owners out there.
Have been out on my maiden voyage today and am generally ok with it apart from fuel leaking from one carb overflow and an annoying drumming vibration at certain revs. Checked exhaust system and found the link pipes fouling where they go through the rear arms, adjusted these and it is much better but still some drumming. Gave it a good coat of looking over underneath and noticed the sump is touching the steering rack so think this is the problem.(conversion done by another not me so looks to have been like this some time!)anyone else had this, how did you overcome it? seem to recall reading sometime about spacers on the crossmember which doesn't look too easy with everything in situ as well as I suspect throwing the wheel alignment out which I have just had done.is it possible I thought to just lower the rack slightly by adjusting the mounting holes-just a thought.
any thoughts/suggestions greatly appreciated.
cheers Rob.

[73stagman]

There is very little room for the pipes across the top of the rack and mine have been modified to suit.... bent out of the way. The rack itself is clear of the sump by a good margin.
Some conversions have a shims / spacers between the front cross member and the shell to increase the gap. Mine doesnt have these spacers but I have the humped bonnet.

[rac]

Appreciate quick reply Neil
Yes looks like the pipes have been modified don't go across the top of the rack but can't even get a sheet of paper between it and the sump .No hump in the bonnet-twin stromburgs- praps this is why engine is sat lower but it beats me how someone can go to the trouble of converting then not sorting this issue??

[73stagman]

Agreed. The hassle of changing the engine is far under estimated. There is some idea that you can just pull a Stag engine out and drop in a Rover V8. That is rubbish as there are some many things to consider apart from the value difference.

As a plus for you if the engine has been lowered on its mounts you can fit these spacers and get you clearance back without raising the engine in the bay. You may have to change the front springs to ensure your ride height remains correct. (And I have a spare pair of plates that you can have if you want them.)

[rac]

Thanks for the offer Neil I will let you know - how thick are they?? What I'm going to do I think initially is unbolt the rack and see how tight it is up to the sump and how much clearance I need-just missing it I think will suffice. The ride height seems ok 14ins wheel centre to the wheel arch so hopefully I wont have to re-adjust this. At least the converter addressed this bit why not the other??
I mean it drives fine no nasty bumps/knocks or anything just this damn drumming doing my head in.

[73stagman]

The spacers are about 10mm thick. which is about the space I have between the sump and the rack. As i said tough I could do with the 10mm at the top of the engine for a decent air filter. My car looks a bit of a "seventies boy racer" so it sort of works with the hump in the bonnet, the low stance and the raucous exhaust

[jakesmig]

Depending on the type of engine mounts you have you could try inserting some suitable penny washers to ease the engine up slightly, works for fine tuning the height. I didn't have a bonnet bulge with my 3.5 which ran with an eddelbrock and I don't have a bulge with the 3.9 although I had to shave the plenum chamber slightly.
I have an 8mm spacer plate between the chasis leg and the cross member. Inserting a spacer will not affect the ride height of the car, all it will do is decrease the clearance between the cross member and the ground, the rest of the car is unaffected.
if you press the bonnet in the middle it will flex and the deflection will let you know the approx clearance you will have.

John.

[rac]

Depending on the type of engine mounts you have you could try inserting some suitable penny washers to ease the engine up slightly, works for fine tuning the height. I didn't have a bonnet bulge with my 3.5 which ran with an eddelbrock and I don't have a bulge with the 3.9 although I had to shave the plenum chamber slightly.
I have an 8mm spacer plate between the chasis leg and the cross member. Inserting a spacer will not affect the ride height of the car, all it will do is decrease the clearance between the cross member and the ground, the rest of the car is unaffected.
if you press the bonnet in the middle it will flex and the deflection will let you know the approx clearance you will have.

John.

cheers John will look at that

[73stagman]

I have an 8mm spacer plate between the chasis leg and the cross member. Inserting a spacer will not affect the ride height of the car, all it will do is decrease the clearance between the cross member and the ground, the rest of the car is unaffected.


John.

That cant be exactly true although it might be the best acceptable way.
If the cross member is closer to the road then the angle that the lower control arm approaches the wheel hub must also be affected as it will sit closer to the road at its inner end. That by default must affect the camber angle even if it is only slightly. Also the reason for doing this is to lower the steering rack and so the steering geometry must also change slightly although this will be easily readjusted.

[jakesmig]

Agree that camber will change if you insert a spacer but it would be so slight you probably wouldn't notice.
The height of the front of the car is solely determined by the length of strut, which is determined by spring rate and length, so the spacer only really affects the cross member clearance.

John.

[73stagman]

Agreed the change in camber angle would be very small and having thought again it might be infintesimal as the ball joint probably takes up the difference with the cammber angle being set by the strut top and bottom mount. Obviously the gain in bonnet clearance is a greater benefit and also improves the sump to rack clearance gap.

[jakesmig]

Stagman,
Going off on a tangent, i'm going through a rebuild / refurb at the moment and intend looking at the front suspension to try and improve turn in. Do you have any information on what the correct castor angle is?
Increasing castor angle slightly should improve turn in and also dampen down the soft feel of the power steering, which is present on my car, but there seems to be a limit of around 5 degree positive castor beyond which it becomes counter productive.

John.