Re: Smoking MF 35 (23C)

Posted by David on February 24, 2003 at 14:54:24 from (62.252.128.10):

In Reply to: Smoking MF 35 (23C) posted by Chris on February 22, 2003 at 13:25:09:

Here's my theory about the 23c. Perhaps its nonsense but after a bit of study of the topic a while ago, I don't think so. Please pick holes in it if you can as, if someone has a better idea, I'm keen to learn.

The 23c is an indirect injection engine and such engines have a greater surface area/cylinder volume ratio than direct injection engines. This means that the charge of fuel/air cools quicker becasue of heat loss to the bigger surface. Usually, to get them going, indirect injection engines need heater plugs in each cylinder (like most diesel cars have - i don't suppose you have diesel cars in the US) The 23c doesn't have that but has to rely on the thermostart in the manifold to get things hot enough to fire and it just isn't that good at it. If compression is low, or its cold the engine just can't get enough heat generated and won't start although the driver usually has generated a fair bit by that time. I suspect that what is happening is that after your rebuild, the compession is improved enough to get the engine going but the indirect design is still cooling the cylinder charge quite quickly and so its not firing fully leaving the white smoke of unburnt fuel in the exhaust. (as you get when it turns over but doesn't fire) Once it gets a bit of heat up things improve.

I reckon that basically the 23c needs individual cylinder heater plugs in it like cars have to be able to really start properly. Usually these plugs are used to pre-heat the engine and also run for a short time after it starts (on a relay) to let it get a decent heat up before switching off. I bet that would cure all its starting problems but probably can't be done without a total cylinder head redesign so the theory is not a brilliant practical prospect. I have also seen an article about modifying the combustion chamber to allow a degree of direct injection which allegedly improved things but would be loath to try it myself unless I had a few spare combustion chambers and maybe a head or two to experiment with.

However, if yours will start easily I'd be grateful for that and leave well alone.

Follow Ups:

• Re: Re: Smoking MF 35 (23C) Chris 01:11:12 02/25/03 (0)

Post A Followup Name: E-Mail: Subject: Re: Re: Smoking MF 35 (23C) Comments: Optional Link URL: Link Title: Optional Image URL: Email Notification: If you check this box, email will be sent to you whenever someone replies to this message. Your email address must be entered above to receive notification. This notification will be cancelled automatically after 2 weeks.

TRACTOR PARTS	TRACTOR MANUALS

We sell tractor parts!  We have the parts you need to repair your tractor - the right parts. Our low prices and years of research make us your best choice when you need parts. Shop Online Today. [ About Us ]