To chassis mount, or not to chassis mount

Sunbmw · Post by **Sunbmw** » Mon May 02, 2011 5:12 am

Hi all, in most Rally cars I have built (Talbot Sunbeams, Escorts etc), I have ended up chassis mounting the engine, this gives a few advantages regarding stiffness, ease of changing suspension components and also being able to mount the engine in a more suitable position.

I have just been weighing the job up when it occured to me that the Rover V8 block isn't the most stiff or strong of things (I do have an X-bolted block mind), and was throwing it out to you guys for opinions, good or bad idea?

I'll start, it maybe an advantage to have the engine as a "Stressed member" as it may add to the rigidity of the block.

I intended to use this kind of kit but replicate it myself.................

http://cgi.ebay.co.uk/Vauxhall-XE-16V-E ... 1c18d6f49e

Look forward to this one................

Post by **Rossco** » Tue May 03, 2011 4:39 pm

The Repco Brabham F1 used the engine as a stressed member without any problems.

ian.stewart · Post by **ian.stewart** » Tue May 03, 2011 5:21 pm

I have my engine Chassis mounted in my Cortina on small box tabs on the chassis, works well, the only down side of it that I have found is, if you remove the X Member with the engine in situ, the rails spread a small amount, [2-3mm] making re-fitment of the X member a bit harder than I would like, But a big sash cramp takes it back without any effort,
Its probably more to do with the construction of the car from fords than any other reason, and Yes I would go that way again, it enables you to fit cotton reels almost direct to the chassis and keep the mounts nice and small, the cotton reels I use are HD Landrover items from Dingocroft

Sunbmw · Post by **Sunbmw** » Tue May 03, 2011 10:36 pm

Cheers guys, I had been erring on the side of mounting to the chassis anyway, but just wanted someone else to say it was a good idea, now, wheres that welder.............

Sunbmw · Post by **Sunbmw** » Thu May 12, 2011 8:33 am

Well, I did it, had a good day yesterday, positioned the engine and fabbed some mountings up, got the engine nicely back and down too...........

In position.........

Tack on chassis brackets..........

Tack tubes to bush mounts, I have used the V8 mounts but modified them and cut them down...............

Fitted the heads and covers to check clearances..........

Then take em off and weld them properly.............

All done..............

Then finish the chassis side of the job..........done!

RoverP6B · Post by **RoverP6B** » Fri May 13, 2011 9:36 am

That looks tops..

You are a seriously handy fella!

Ron.

stevieturbo · Post by **stevieturbo** » Fri May 13, 2011 9:44 pm

The concerns I would have there are how leverage is now acting on the mounts, and weight is hanging from them.

IMO it looks there will be more loads chucked through the tiny upper mount ( single bolt ), than the lower fixings on the block body.

Darkspeed · Post by **Darkspeed** » Sat May 14, 2011 8:59 am

Stevie +1

Tubes should only carry loads in tension or compression they are not designed for bending loads.

Andrew

stevieturbo · Post by **stevieturbo** » Sat May 14, 2011 3:08 pm

It's not even the tube I'm talking about. I'd say it's strong enough as does look fairly substantial.

More about how it interacts with the block fixings. It just looks wrong as all the loads will be distributed to the wrong places.

Although the actual rubber bits look good, what are they off ?