Board logo

BEC engine mouting soft or hard?
franky - 15/9/09 at 09:11 PM

As above, been having a 'discussion' with a friend over the merits of the above....

I'm undecided, he reckons a solidly mounted motor.

What would be the best type of anti-vibration mounts suitable or engine type mounts for a BEC?

Dangle_kt - 15/9/09 at 09:17 PM

solid.

I may be wrong but I havn't seen any soft mounted bike engines. Not even in bikes - (thats right I don't class Harleys as bikes!)

designer - 15/9/09 at 09:27 PM

Why not use metalastic bushes, fairly solid and might take out a few vibrations?

adithorp - 15/9/09 at 10:05 PM

Mines mounted on metalastic bushes.

adrian

ReMan - 15/9/09 at 10:09 PM

I like the idea of a slightly more compliant mounting just to lose a bit of harshness, but, I think you'd have to be very careful not to stress the engine mounts outside of their design?

mark chandler - 15/9/09 at 10:55 PM

poly bushes for me, used landrover panard bushes, you can turn these down for a perfect fit, nice and cheap.

sickbag - 15/9/09 at 11:02 PM

I would have thought it was personal preference, but do remember that most of the motors used in BECs were designed to be rigidly mounted in the bike chassis they came from, and actually formed most of the bikes chassis rigidity.

nitram38 - 15/9/09 at 11:10 PM

MotaLeira R1 solidly bolted into the chassis. No issues with vibration.
More important if you have a chain drive. The last thing you want is a slack chain as the motor moves about!

tomblyth - 16/9/09 at 07:38 AM

mines on Car engine rubber mounts at the front and metal elastic bushes at the back!

motorcycle_mayhem - 16/9/09 at 08:36 AM

Mine's on metalastic bushes, pretty firm ones. Why? Dunno, it's how I did it at the time. Result has been brilliant.
NB, I have a propshaft set-up. If you're doing a (more) sensible mid-engine/chain combo, you need to rigidly mount everything.

As an aside, the Sprint R, mid-engine/chain, uses(d) a fairly sloppy rubber frame mounting by comparison, but the diff/chain was part of the frame with the engine. Probably a good set-up if middle age prostate hang-ups mean you can't sit in a vibration without wanting to go all the time.... don't ask.

scotlad - 16/9/09 at 08:45 AM

My Indy was solid mounted with no issues at all

PAUL FISHER - 16/9/09 at 09:56 AM

quote:
Originally posted by motorcycle_mayhem

As an aside, the Sprint R, mid-engine/chain, uses(d) a fairly sloppy rubber frame mounting by comparison, but the diff/chain was part of the frame with the engine. Probably a good set-up if middle age prostate hang-ups mean you can't sit in a vibration without wanting to go all the time.... don't ask.


The 1st run of early Sprint R's had rubber mounts,they had problems with too much movement in the engine,all sprint R 's since have been solid mounted.
My vote would be for solid mount as in the bike,Ive not noticed a problem with vibration on any BEC's Ive drove and owned over the years,and lets face it you don't drive a BEC for the ultimate in refinement.

Gav - 16/9/09 at 09:57 AM

My blade engine has bolts through the top mounts to a plate which swivels in bush on the cradles main frame.
The bottom mounting had poly bushes.

Pic 1

Pic 2

Mr Whippy - 16/9/09 at 11:06 AM

why not fit the metalastic mounts to the seat instead? especially if it a GRP one. You could easily do the same to the column to isolate you hands from vibrations.

SPYDER - 16/9/09 at 03:26 PM

Metalastik bushes on our Phoenix. The diff is poly bushed.
Geoff.

lsdweb - 16/9/09 at 04:49 PM

What would Colin Chapman do?!

Solid mount for stiffness. Probably make it a stressed member of the chassis / car and then remove some of the other unnecessary chassis members... :-)