Engines etc

amazon69 · #1 (**permalink**) 20-07-14, 02:16 PM

Hello,

Can someone enlighten please as to the reason for the front suspension being changed for the 407 from the 406? Was it due to the weight of the v8 engine upsetting the handling over the straight 6? And does anyone know the weight of the original 6 cylinder engine?
One more thing…what is the difference in the rear diffs across the 2 models? How much power can the original 406 diff/axle take?
Thanks a lot.
Dave

GREG · #2 (**permalink**) 20-07-14, 03:27 PM

And it also changed from a steering rack to a steering box -- what are you planning ? :-)

amazon69 · #3 (**permalink**) 20-07-14, 05:18 PM

I don't know what I'm planning yet, not until I know various facts etc. It's no good putting a 300hp motor in if the car steers and stops like a boat. I have the option to put whatever motor I want in my car, but I don't want to kill myself driving it.

Stefan · #4 (**permalink**) 20-07-14, 06:43 PM

I think its not only the weight of the v8, but the width that needed a wider front beam. Sadly this meant losing the rack and pinion steering of previous 2 litre models but the transverse leaf spring could be replaced with simpler coil springs.
The v8 conversions Ive seen at Brabazon had a replaced front beam for this reason I think.

GREG · #5 (**permalink**) 20-07-14, 06:45 PM

Look at an old thread from Clive who was planning a Volvo engine in his 406 using a 410 rear axle / diff

Clive sadly passed away just before completion.

A Rover V8 would be lighter than a Bristol engine

I think the Discovery channel programme on UK TV is still online that shows a V8 put in a 406 , but you could get similar power levels from a lot of modern 4 cylinder engines.

Maybe join one of the owners clubs to chat to someone that has a 406 with a non Bristol engine in -- quite a few exist !!

Geoff Dowdle · #6 (**permalink**) 20-07-14, 07:39 PM

Dave ,
A 6 cylinder Bristol engine weighs approx. 350lbs/159kgs .
A standard Rover V8 should be a idea option for a 406 , approx. same weight , it should fit behind the original front cross member and there should be enough width in the engine bay . A 5 speed manual box would suit.
The diff is a Salisbury which should take up to about 300bhp without a problem , and the standard disc brakes should stop it (maybe with better front calipers using larger pads).
The less modification the better , saves cost & time and in the future when people start returning these cars back to original condition it will make the job a lot easier.

I expect BCL changed to a coil spring /wishbone front suspension on the 407 to allow the 313 V8 engine and auto to fit low in the chassis. The front of the 6 cylinder engine sits over the top of the transverse spring/cross member .

Good Luck
Geoff

amazon69 · #7 (**permalink**) 20-07-14, 09:05 PM

Thanks all, appreciated. I think I have Clive's old car. I'll search out the old thread. Looking at the engine bay today it seems odd that the cross member would have been changed to accommodate the v8, it looks massive in there to me. Especially when the bulkhead has disappeared

Lots to learn.

Kevin H · #8 (**permalink**) 20-07-14, 11:41 PM

It was Clyde Lennon, not Clive.

His 406 bore the registration 4545 WJ and the chassis number was 406/5259

You can do a search of this forum for Clyde's posts or threads using the Advanced Search function. Clyde's username was 406Special

I've had a quick look myself but I could only find discussions on what "might" be a suitable replacement engine. However I know Clyde ended up doing quite a lot of work on this and decided to use a 2.5L Turbo Volvo engine.

I'm sure I have some detailed information about this somewhere, but I can't locate it at the moment.

The guys at Alpine Eagle were doing the work on Clyde's car so they might be able to provide some more information. I went along with Clyde to visit Alpine Eagle one day and if I remember rightly they had started preparing the engine bay.

amazon69 · #9 (**permalink**) 21-07-14, 06:12 AM

Thankyou for that clarification Kevin. It is his old car. I would be very grateful for any and all info about it…I found the old thread, that was helpful, and the name of the people working on it is very helpful too. I had heard about a straight 5 Volvo motor going in there, maybe he';d moved away from the ideas of the 4 cylinder red block. I am a big Volvo fan myself, the clue's in the username, so I can understand him being a fan of the engines. I have a lot of missing parts, a massive hole in the engine bay, floor and bulkhead area, and lots of plans. It would be good to think that I could carry the spirit of the build on. Thanks again.
Dave