4 replies to this topic

[monaghanrl]

Hi,
I know the subject of tappet clearances has been discussed many times on this forum, but after reading through some of the threads on here I am still a bit confused.

I have a 1989, 998cc mini and I want to adjust the tappets but I'm not sure what to set them to.

I have read that for a standard 998cc mini all the tappets should be set to 12 thou... however, on reading some other threads, it seems that some recommend setting the inlet valves (2, 3, 6 and 7) to 12 thou, while setting the exhuast valves (1, 4, 5 and 8) to 15 thou.

What is the general recommendation for this sizze of engine?

Are there any benefits to setting the exhausts to 15thou rather than 12thou?

Thanks

Rob

[jaydee]

Some of us set exhausts wider due to the extra heat of the gasses, inlets then to be cooler.
12 thou inlets and 15 thou exhausts sound quite good, although i've never had a problem setting both 12 thou on a bog standard 998.

[Cooperman]

As 'Jaydee' says. 12 thou for inlets & exhaust is corect for a standard 998. That is what the original BMC/BLMC Worksho Manual specified. The 0.015" for exhausts is really for modified engines.

[monaghanrl]

Thanks for your replies, that's really helpful.

I think I'll just stick to 12 thou for both inlet and exhaust as my engine is not modified.

thanks again for the help :)

[Big_Adam]

Its also written on the back of the cast manifold if you got one.