hi, Does anybody know the size of the thread on the engine end of the exhaust stud on a 93 fireblade? the web seams to think its M8 reduces to M7 and 45mm is that right?

[Edited on 19/7/12 by ceebmoj]

I think they are m6 or m7 metric fine thread, but what I've done with mine is taped them out to m8 and fitted high tension bolts in place of the studs, with the extra weight of the exhaust and silenced loadings, it makes for a more sercure job.


[Edited on 19/05/04 by PAUL FISHER]

They are M7.
But I too did as Paul suggests on my first and second Blade powered Cars.
It's not just the added weight, it's finding spares at short notice; TD's, Road trips etc...

To tap them out to M8, Is it just a matter of running an M8 tap in to the block or do you need to drill the existing hole out first?

METRIC COARSE SIZES
----------------------------
TAP DRILL
SIZE SIZE
----------------------------
1mm x .25 .75mm
1.1 x .25 .85
1.2 x .25 .95
1.4 x .3 1.1
1.6 x .35 1.25
1.7 x .35 1.3
1.8 x .35 1.45
2 x .4 1.6
2.2 x .45 1.75
2.5 x .45 2.05
3 x .5 2.5
3.5 x .6 2.9
4 x .7 3.3
4.5 x .75 3.7
5 x .8 4.2
6 x 1 5
7 x 1 6
8 x 1.25 6.8
9 x 1.25 7.8
10 x 1.5 8.5
11 x 1.5 9.5
12 x 1.75 10.2
14 x 2 12
16 x 2 14
18 x 2.5 15.5
20 x 2.5 17.5
22 x 2.5 19.5
24 x 3 21
27 x 3 24
30 x 3.5 26.5
33 x 3.5 29.5
36 x 4 32
39 x 4 35
----------------------------
METRIC FINE SIZES
----------------------------
TAP DRILL
SIZE SIZE
----------------------------
4 mm x .35 3.6mm
4 x .5 3.5
5 x .5 4.5
6 x .5 5.5
6 x .75 5.25
7 x .75 6.25
8 x .5 7.5
8 x .75 7.25
8 x 1 7
9 x 1 8
10 x .75 9.25
10 x 1 9
10 x 1.25 8.8
11 x 1 10
12 x .75 11.25
12 x 1 11
12 x 1.5 10.5
14 x 1 13
14 x 1.25 12.8
14 x 1.5 12.5
16 x 1 15
16 x 1.5 14.5
18 x 1 17
18 x 2 16
20 x 1 19
20 x 1.5 18.5
20 x 2 18
22 x 1 21
22 x 1.5 20.5
22 x 2 20
24 x 1.5 22.5
24 x 2 22
26 x 1.5 24.5
27 x 1.5 25.5
27 x 2 25
28 x 1.5 26.5
30 x 1.5 28.5
30 x 2 28
33 x 2 31
36 x 3 33
39 x 3 36
----------------------------

A 6.8mm clearance drill would suggest that you could get away with just running the tap down it, but I drilled mine to be on the safe side. That and I happened to have a 6.8mm drill bit handy...

M7