Interference engine question

[snowwolf]

I know a lot of Toyota's if the cam belt breaks, the pistons don't hit the valves, is this the case for the 2.4 TD surf

[Guest]

I know a lot of Toyota's if the cam belt breaks, the pistons don't hit the valves, is this the case for the 2.4 TD surf

Snowwolf.

If your cam belt breaks the pistons will definately hit the valves. The head on the 2LT/2LTE is a flat face type with the valves sitting flush to the head face (i.e. not recessed) and the TDC position of the piston crown is almost flush with the block face. The only combustion space is the thickness of the gasket and the small amount of clearance from the top of the piston crown. However this is the case with Diesel engines as they are compression only ignition and therefore run very high compression ratios.

Heads that you don't have this problem with are almost invariably on spark ignition (petrol) engines where they run domed heads or dished pistons (some run valve clearance cutouts in the piston crown).

An example of this is the Hemi head 440ci Chrysler / Dodge V8. It wouldn't run with cam chain failure but it certainly won't cause the valves to come into contact with the heads.

You will probably find that the Toyota engines where this is the case are the V6 engines and also the small multi valve VVT engines.

Cheers

[Cmar]

The famous 4E-FE 1.6 16v engine is the same. That engine is found in the mkI mr2 and the corolla gt (RWD twin-cam). This is going back to the late eighties.

[snowwolf]

interference engine

http://www.angelfire.com/ar/dw42/freewhee.htm have a look at this site, it does say it would be fine, and I had read somewhere else that all Toyota engines are non interference, I just hope I don't find out the hard way.

[Guest]

http://www.angelfire.com/ar/dw42/freewhee.htm have a look at this site, it does say it would be fine, and I had read somewhere else that all Toyota engines are non interference, I just hope I don't find out the hard way.

I think I would make the assumption that damage will occur. Having just done the cylinder heads on 2 Surfs I think I can safely say that unless the cambelt fails with all valves closed or nearly closed then they are going to hit the head. It's best to change the cam belt on these motors as a matter of course when you first get them, it's not that expensive and at least you know it's been done. We really don't know on most of them how many miles they have done as a lot tend to get clocked at the docks. It's also relatively easy to do yourself if you are handy on the spanners.

Cheers

[snowwolf]

interference

I think your right, Lucky, the only reason I was worried about changing the belt, is the bleeding of ALL the air from cooling system after refilling it.
And that could be more of a problem and cost to changing the belt, I have looked at the "burping of the radiator" what a lot of hassles that looks, and what happens if you don't get all the air out? A cracked head!

[Koi]

I think your right, Lucky, the only reason I was worried about changing the belt, is the bleeding of ALL the air from cooling system after refilling it.
And that could be more of a problem and cost to changing the belt, I have looked at the "burping of the radiator" what a lot of hassles that looks, and what happens if you don't get all the air out? A cracked head!

I think you should be able to change the belt without draining anything down.

[snowwolf]

mmmmmm now thats got me thinking.....anyone help on this last post?

[Koi]

mmmmmm now thats got me thinking.....anyone help on this last post?

Look here for some more info

http://www.yotasurf.co.uk/Forums/sho...ht=cam%2A+belt

[Guest]

I think you should be able to change the belt without draining anything down.

Koi's right. you should be able to do it although it makes access a bit more awkward not being able to take off the top hose however it is possible.

Cheers

[snowwolf]

mmmmm I will do it myself I think, at the end of the day it's only nuts and bolts and thats my job! if anyone has changed the belt themselves, pass on any tips!