ClioSport.net
Register a free account today to become a member!
Once signed in, you'll be able to participate on this site by adding your own topics and posts, as well as connect with other members through your own private inbox!
-
When you purchase through links on our site, we may earn an affiliate commission. Read more here.
How to check for worn valve guides?
- Thread starter sam JFM
- Start date
You wont realistically get a gauge in there, best you can hope for really is get some accurately machined pins to use as feeler gauges to check the size in both directions and see if its oval or not.
But I just go by feel with a valve to decide if they need doing or not.
But I just go by feel with a valve to decide if they need doing or not.
p@blo
ClioSport Club Member
Clio/A3
Yep, a small bore gauge will fit & 'seemed' to give meaningful ref of each axis & any taper in the guides in relation to the stem measurements.
Using a dial gauge to measure side float on the valve was a ball ache and found it tricky to get consistent readouts on mine.
Just curious how us mere mortals would determine at what point in the acceptable tolerance they were too worn.
Would most of the f4rs out there have 'some' degree of ovality/valve float yet still sit within tolerance?
Using a dial gauge to measure side float on the valve was a ball ache and found it tricky to get consistent readouts on mine.
Just curious how us mere mortals would determine at what point in the acceptable tolerance they were too worn.
Would most of the f4rs out there have 'some' degree of ovality/valve float yet still sit within tolerance?
172 Rally Car
Sam, your belt skipped?
Genuine question - how would you quantify any OOR in guides/stems without a small bore gauge & micrometer or alternatively a dial gauge? Chip?
Yeh got another one with a slipped belt but I don't want to spend a fortune replacing valve guides if possible.
How much are we saying is too much then guys? Or just check them and find the ones that are worse (if that makes sence)
Yep, a small bore gauge will fit & 'seemed' to give meaningful ref of each axis & any taper in the guides in relation to the stem measurements.
Using a dial gauge to measure side float on the valve was a ball ache and found it tricky to get consistent readouts on mine.
Just curious how us mere mortals would determine at what point in the acceptable tolerance they were too worn.
Would most of the f4rs out there have 'some' degree of ovality/valve float yet still sit within tolerance?
I think its only ones which have had hotter cams that are really likely to have issues, in the main the F4R guides seem to last very well.
For example. My mrs old 172 has done 151K miles
When I pulled it apart at 141K miles, the valves felt so good by hand I didnt bother changing the guides when I put it back together, its been perfect for another 10K miles since, about half of which was clocked up on trackday or ring trips so not exactly being pottered around, even on the drive back from the ring it was at nearly 6Krpm for 2 hours at once point (late for ferry).
p@blo
ClioSport Club Member
Clio/A3
Furry muff
Ah right
Assuming its a 736, tolerance is listed between 5.462mm to 5.480mm on the inlet valve stems and 5.438mm to 5.456mm on the exhaust valve stems.
The clearance tolerances are listed as 0.020mm to 0.056mm for the inlet valves and 0.044mm and 0.080mm for the exhaust valves.
