Z1OwnersClub GB

zed1015 wrote:

cakeman wrote:I assume I can use either a Unitrak head or a B2 head ? Are there any other's that are compatible?

No. Unitrack head has different (steeper) exhaust valve angles to the B2 and all the others.
If you have a unitrack bottom end (18mm gudgeon pins) you need to use the Uni head unless you want to get into modifying the exhaust valve pockets on the pistons.

Great info, cheers for that. It looks like I'm after a B2 head then as the bottom end is B1 (according to the engine numbers) as the castings above the inlets are not present. Are there any other heads that are compatible with a B1 engine and barrels?

If it's a B1 motor then a 'J' head will fit or any with a full hemi (non bathtub) 70mm combustion chamber.
Having 'B' engine numbers does not mean it is B spec as the cases are the same as the unitrack and the internals are interchangeable.
You need to measure the gudgeon pin diameter as only the UNITRACK had 18mm pins and all the others are 17mm.
To be sure of what you have post a pic of the head showing the valves.
Also the UNI head has a letter 'A' stamped in each of the inlet tracts unless it has been erased by porting .

zed1015 wrote:If it's a B1 motor then a 'J' head will fit or any with a full hemi (non bathtub) 70mm combustion chamber.
Having 'B' engine numbers does not mean it is B spec as the cases are the same as the unitrack and the internals are interchangeable.
You need to measure the gudgeon pin diameter as only the UNITRACK had 18mm pins and all the others are 17mm.
To be sure of what you have post a pic of the head showing the valves.
Also the UNI head has a letter 'A' stamped in each of the inlet tracts unless it has been erased by porting .

More great info again cheers, I did wonder about the stamps just inside the inlet tract, mine has "5" stamped in them. I'll post a picture later.

Here's a picture of the head.

It's hard to tell in the pics with all the carbon and shadows but that doesn't look like a Uni head so most likely a B.
If that's the case you want a B or a J head but the thread damage you describe could easily repaired by a good machinist like the head in the following pic that was repaired by Debbens.

Here's a clearer pic of a Uni combustion chamber to be sure.
Note the deeper "Bathtub" area of the chamber where the valves sit.

I'll definately give Debbens a ring zed, that looks just like the kind of repair I need doing.
Thanks for the help, very much appreciated.

So, take two, engine assembled with new gaskets, valve seals etc. just waiting for the cam cover gasket to arrive and it’ll be time to put it back in the frame at last.

Looks great well done.

AL

Did you paint the engine yourself?

walshyco wrote:Did you paint the engine yourself?

Yup, had the engine soda blasted to remove the old layers of black paint and then ended up spraying it in the back of me old Maxus van as the garage is full at the moment lol, makes a handy spray booth tbh

Engine in the frame and forks fitted. Apologies for the quality of the picture, it was late and a bit cramped lol.

Looking good

How much fun was getting the motor in? My Suzuki engined Magnum was like one of the Chinese puzzles you used to get in crackers at Christmas. The only way was to lower the frame over the motor, twist, tilt, turn and prey. Never taking that out again!

martinz1000r wrote:How much fun was getting the motor in? My Suzuki engined Magnum was like one of the Chinese puzzles you used to get in crackers at Christmas. The only way was to lower the frame over the motor, twist, tilt, turn and prey. Never taking that out again!

Really easy tbh, lowered the frame over the engine, rear mounting bolt in followed by the fronts....job done, then realise that it wasn't a clever move to leave the rocker cover off, so, remove the rear mounting bolt and lift the frame enough to pop the rocker cover back on lol.....going to be fun doing the shims in the future

Not updated for a while due to picking up some lurgy type bug but have managed a few bits and pieces. Rear wheel and spacers are all sorted, ended up using a gsx750f rear wheel complete with disc, caliper carrier and sprocket carrier, it all lined up to within a mill and the chain run is cock on which was a result, just needed a couple of spacers on the brake side which needed to be 20mm in length and another 25mm long with a 20mm bore and as luck would have it found the exact sizes on eBay for £16 in stainless. Also ordered a set of Delkevic downpipes from D&K which arrived today so I found a bit of time to get them fitted this afternoon, must say the quality is great and they fitted perfectly, very impressed for £170 and I only ordered them Monday afternoon. Here’s a pic.