10 replies to this topic

[daenesh]

hey guys.. how't it going? I would like to inquire as to the tappet Gap on my 998 A+ engine.. the only catch is that im using a 1098 camshaft.. now does this make a difference or do i still set them all to 12 thou/30mm? Any advise would be greatly appreciated.. thank you!

[HarrysMini]

Different people have different opinions, but I set mine to 12 thou inlet and 15 thou exhaust. 

 

Someone will have to confirm whether or not the cam will make any difference. 

[daenesh]

thanks for the reply.. i thought the 12 thou and 15 thou was for the 1275 and metros?

[Cooperman]

12 thou is really fine for all Mini engines unless running 1.5:1 rockers.

The reason for the gap is to prevent the valves failing to close due to expansion when hot. In fact, for a Mini valve to expand enough to close up a 12 thou gap would require a temperature at which the engine would have already seized up. I can't be bothered to do the calculations, but it will be fine at 12 thou for both inlet 7 exhaust. The cam is of no consequence here.

[exuptoy]

So what gaps are advisable for a 1275 running 1.5 roller rockers?

[Cooperman]

I set 0.015" in and ex on my 1310 cc 'S' with 1.5 rockers and have never had any problems.

[olly33]

I have just set mine to 0.015" inlet and exhaust, for a 1275 with standard rockers with 276 cam, hope thats correct,as some did seem smaller before adjusting?

[Stiggytoo]

No, 15thou is not correct. You want 0.012" inlet and 0.015" exhaust.

[olly33]

No, 15thou is not correct. You want 0.012" inlet and 0.015" exhaust.

ok, cheers bud.

[daenesh]

thanks for all the replies.. that cleared it all up.. and thanks Cooperman :)

[exuptoy]

I set 0.015" in and ex on my 1310 cc 'S' with 1.5 rockers and have never had any problems.

Cheers dude.