1600M engine replacement - Crank breather and petrol blank

[RobStan]

Hi all

I'm in the process of switching engines on the 1600M. The new block doesn't have a crank breather as the old one did, nor does it currently have a blanking plate for the old fuel pump.

My questions are:

• What's the best plan for the crank breather and if I reuse the old one where do I get the seals?

You can just see the old one on this photo but only if you look hard. I've since taken more bits out of the engine bay since so I can provide more pictures.

• What's the purpose of the petrol blanking plate with the deflector?

Cheers
Rob

[timelord]

The crossflow engine needs as much crankcase venting as poss, especially if tuned. Burton are a probably the best source of parts. The fuel pump blanking plate deflectur is to stop the oil that would have been thrown at the mech fuel pump arm from forcing its way through the blanking plate gasket. I also use a later oil cap with breather linked into the breather pipework to help vent the top of the engine. Geoff

[RobStan]

Cheers for the info on the blanking plate for the petrol pump.

As far as the crank breather goes, are you say that you've also blocked this hole and used another breather system instead? If so what have you done?

Cheers

[heightswitch]

Rob.

Burton sell a push in adaptor union that fits the block in place of your canister breather it is an interferance fit and sometimes too large so you have to freeze it / turn it before tapping into the block. The best way of breathing the engine is to run a pipe from the union fitted to the block to a catch tank. I am very wary of after market rocker covers with cheap caps which also don't breath so I would advocate drilling and tapping the rear top of your rocker cover and also piping to the catch tank.

the catch tank should be vented with a filter (you can buy them cheaply and they look like small K&n filters specifically for catch tanks.

Mocal do a 1 ltr one with 2 points in left and Right hand to give you flexibility regards mounting

from memory you will also need to blank off the inlet manifold connection with a BSP plug where the old breather used to be piped into.

This mod essentially stops the polluted oil contaminated hot air going into your inlet and blurts it out to atmosphere instead

I will try to find a pic of the arrangement

This probably explains it well enogh though Rob.

http://www.burtonpower.com/technical_1/engine_brea...

And this is the union..
http://www.burtonpower.com/pic_viewer.aspx?picpath...

just checked website. one for a 711M and one for a 681F crossflow 23mm and 20mm respectively


Neil.

Edited by heightswitch on Wednesday 27th May 17:27

Edited by heightswitch on Wednesday 27th May 17:33

Edited by heightswitch on Wednesday 27th May 17:36

[RobStan]

I've pulled a few more bits off now and got a clear shot of the breather here

Thanks for the advice and help. I guess I need to find a breather tank that'll fit somewhere.

Rob

[timelord]

If you nare going to be using a single carb on your engine build its worth using the original breather connected to the carb as this creates a slight negative pressure in the crankcase helping to prevent blowby from the crankcase, oil into the top of the engine. This doesn't work on twin sidedraughts as air can be sucked back causing an imbalance in the carbs. I have twin 40s on mine hence the Burton breather connection and catch tank mounted on the bulkhead above the exhaust manifold with sufficient room to drain the moisture out regularly. Geoff