Right so I'm going to be building DTR engines for my 2 DTR projects. What I'm trying to find out is about cylinder heads and squish bands.

There are various different cylinder heads and in the detonation area is where they vary. Some are smooth and some have a band which i presume is a squish band?

Does this then mean that heads with that squish band are going to produce better power? Some people seem to think it should be smooth?

I'm confused!

Any help would be good!

the squish band is the band around the combustion area that has a very small gap between the piston and the cylinder head...when the piston is at TDC, some of them have this convoluted groove in them (i know not why) the best one to go for is the one without this groove IMO

Hmm, why do you say without? I would imagine they only made improvements as they went along so if i can get a photo to see if the RE had the groove i guess we'll know. Or even a TZR125 4DL head. They got the most out of that engine after all.

Don't forget emmissions is as big a problem for manufacturers as power.

That may be the reason for the changes to clean the burn rather than power.

any race bike or high peformance engine, from all manufacturers would be devoid of this groove, the only bike i saw it on was a later model DTR, not sure about the DTRE but the numbers on the casting will tell the tale

Thanks guys, much appreciated. I suddenly remembered it coming up in the de restricting DTR thread and theres lots more on there to prove your theory. I'll clean up my 3MB heads.

I'm looking out for one of the TZR125 4dl/4hw heads too.

What about 34X heads from the earlier LC's? They appear to be smooth. gonna whip one off some of the spares i have. It's on a 3MB barrel at the mo.

your supposed to check squish with a piece of solder from inside the spark plug.

Not sure what the DT is supposed to be though

Stan sephens , has big article on sqiish etc , in this months Practical sports bike,,,