Can anyone advise safe clearance for pushrods?
Old head holes were +12mm and rods are 6mm.
New head has same size holes but new rods are 7.95mm.
Means there is 4.05mm instead of 6mm clearance.
My question is by how much do the rods move fore and aft when the motor is running?
Anyone know please?

_________________
'98 Mpi Sportspack + 7 port alloy head

Isn't it mini(scule)?

I remembered someone had reported rubbing and marks on their pushrods:

http://ausmini.com/forums/viewtopic.php?f=2&t=92701

I think the suggestion that came out was drilling the holes out in the block.

_________________
---
Roads need more corners
A Deluxe(CG13DE), 2 Clubbies(998 and 1275) and 2 Morris 1100Ss

But its the head that is smaller.
You would need to be careful not to go through to the ports. Possible slot the hole maybe?

_________________
1963 Morris 850 Smoke Grey
1963 Morris 850 Shadow Blue
1965 Morris Mini Smooth Van
1966 Morris Mini Van
1969 Morris Mini Deluxe Resto
5/72 Clubman Gt

no... it's the block that has the smaller hole. The rub marks line up with the top of the block - I should take another photo to show where it's actually rubbing

_________________
did I tell you that I won a trophy?

Matt Read used to drill the block holes out.

_________________
DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.

yep, we`ve had to with some, alignment of head to the block isn`t always exactly the same on every block/head combo,,, some rockers/head combos we`ve found (on other peoples engines) in combination with the small hole blocks have made for some serious yukkyness

but i warn about opening the cyl head holes up, it`s do-able with std valve roady stuff,,, but some big heads (like what we do) have huge ports that interfer with the pushrod holes so we sleave them to keep going bigger with port,,, so attempting to drill the push-rod holes in a head like that would cause a bit of anxt, to say the least

just have a good look & a good measure & make sure your cyl head alignment & push rod holes & push-rods & rockers are all set-up with "middle of the road" clearance,,, you only need to look carefully when assembling,,, if it`s all on the wonk then do some spacing &/or drilling

just be carefull

most of the rubbing pushrods (that i`ve found) have come from poor rocker spacing (side ways stuff) but then the worst combo is poorly aligned rockers/head/block with fat push rods & poor spacing with offset rockers added ontop of small hole blocks we drill em if they`re looking suspect on the first dummy build.

_________________
No offence intended here but--> anyone writing a book about minis 30 years ago may not have experienced such worn or stuffed-with components as we are finding these days.

You should put your heart & soul into everything you do.

Thanks all for the details.

_________________
'98 Mpi Sportspack + 7 port alloy head