Jump to content
Click here to contact our helpful office staff ×

My engine's too low`


henry21p

Recommended Posts

Dave, it was pretty low when it was here.

 

Check the engine mounting brackets. Not sure about the K series but the Ford brackets have been known to fracture.

 

Look at the exhaust. Does it look "straight", is it lined up or does it look as if the engine could do with raising?

 

 

Norman Verona, 1989 BDR 220bhp, Reg: B16BDR, Mem No 2166, the full story here

You and your seven to The French Blatting Company Limited

Link to comment
Share on other sites

Erm, or not...

 

Be very careful about this - the standard engine-mount bolts that I have would leave dangerously-little thread in the mounts if padded out with washers... They're marginal as they are.

 

Perhaps someone can correct me, but ISTR the rule-of-thumb being >1.5 bolt-diameters as depth into steel and >2+ into ali.... *confused*

 

Project Scope-Creep is live...

 

Alcester Racing 7's Equipe - 🙆🏻

 

Alcester-Racing-Sevens.com


Link to comment
Share on other sites

Erm, or not...

 

Be very careful about this - the standard engine-mount bolts that I have would leave dangerously-little thread in the mounts if padded out with washers... They're marginal as they are


 

Myles, you do not have my bolts then *tongue*, you are right about how much thread you need, BUT mine is fine, with 3-4 washers so please do not "knock" everyones ideas without knowing the facts..... *mad*

 

Anyway, if that does not suit, how about washers underneath the rubber mounts this give the same effect.

 

In fact this is a very good way of:

a/ lifting engine, taking into account driveline is still true.

b/ raising ground clearances

c/ being able to lower the CoG, because you can lift engine whilst lowering chassis to give better car set-up.

 

 

Martin

 

MW 51 CAT

Superlight No.171

now known as:Superlight DVA 207

Link to comment
Share on other sites

Raising the engine gives a lower C of G *confused* That's a new one on me *tongue*

 

The build manual on my first car stated that it was a perfectly acceptable practice to insert washers under the engine mounting bracket to AVM in order to raise the engine if required to give additional sideskin/exhaust clearance.

 

Brent

 

2.3 DURATEC SV Reassuringly Expensive

R 417.39 😬

Link to comment
Share on other sites

Raising the engine gives a lower C of G That's a new one on me


 

what is happening is that by lifting the engine AND lowering the chassis you are infact probably returning the engine to almost the same ground clearance as before, however this time you are bringing the chassis closer to the ground and it's weight.....hence lower CoG *tongue* *wink*

 

Martin

 

MW 51 CAT

Superlight No.171

now known as:Superlight DVA 207

Link to comment
Share on other sites

It IS acceptable to insert washers between the engine mounting bracket and the rubber attachment - the point is: not too many, otherwise there won't be a minimum acceptable number of bolt threads engaged in the 'nut'.

 

I suppose it would be possible to get some slightly longer bolts - but it would be essential to obtain some of the correct material specification *eek*

 

BRG Brooklands SV 😬 It seems that perfection is achieved not when there is nothing more to add, but when there is nothing more to take away. (Antoine de Saint-Exupery)

Link to comment
Share on other sites

Brent, Yes I am and why? it's simple, the more weight that is lower to the ground the better *thumbup*

 

I've seen plenty of cars that I have set up, with about 130mm clearance under the point where the chassis turns from square to round (mid way from footwell to front of car) they will probably have around 55-65mm sump clearance.

 

When tweeked with washers when allowed, you can end up with 120mm clearance under same point on chassis, still maintaining 55-65mm sump clearance......

 

Thats is very good in my experience.

 

Martin

 

MW 51 CAT

Superlight No.171

now known as:Superlight DVA 207

Link to comment
Share on other sites

Yes, you are quite right when you say the more weight that is lower to the ground the better, but I'm afraid that raising the engine does the exact opposite. With any roadgoing sports car, and a Caterham especially, there is a compromise sought between good handling and practicality. Clearly if the sump is too low there are ground clearance issues which simply aren't a problem on track.

 

1) Since motor racing began and particularly so in the modern high tech era, racing car designers have sought to get the centre of gravity as low as possible in order to assist the handling. Why, in recent years, Renault F1 engine designers even widened the vee angle of their V10 engines, partly because it allowed them to keep the mass of the engine as low in the chassis as possible as it helped to lower the C of G.

2) I would defy anyone to honestly say they could discern a difference in the handling of a Caterham 7 simply by raising or lowering the height of the engine by the thickness of a few washers. I agree you need good sump clearance for the above stated reasons but that is an entirely separate issue to tweaking for handling.

3) How, exactly, is raising the engine with washers bringing the chassis closer to the ground 🤔 *confused* Assuming you are not adding weight nor adjusting the spring platforms, the chassis will be an identical height from the ground regardless of how high you mount the engine (excepting the fact you have added weight with washers *wink*). I am totally bemused by your assertion. *confused*

4) The engine and gearbox are, effectively, an integral part of the chassis and, as such, to lower the C of G of the car, the relatively heavy lump of an engine must be lowered, not raised.

5) I don't doubt that you have set your cars up to handle well at the dimensions you suggest but, at the risk of repeating myself, this has nothing to do with your statement that raising the engine lowers the C of G. It quite plainly doesn't.

 

If you mean that by raising the engine, there is then scope for lowering the chassis on the spring platforms whilst maintaining a given sump clearance then yes, you can play around with the handling whilst retaining a degree of useability on the road but my point was that, in essence, your statement about lowering the C of G by raising the engine is plainly wrong.

 

 

Brent

 

2.3 DURATEC SV Reassuringly Expensive

R 417.39 😬

 

 

 

 

 

 

 

Edited by - Brent Chiswick on 30 Oct 2005 15:48:46

Link to comment
Share on other sites

anyway.. I thought the suspension is best set up on a seven so that the front lower wishbones are parallel to the ground, and then make sure you have enough sump clearance.

 

Raising the engine, so you can drop the chassis below the point where the wishbones are parallel might improve CoG, BUT will comprimise the susp geometry..

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
×
×
  • Create New...