|William Harvey 1||10/06/2021 22:14:59|
|25 forum posts|
I need a press to fit some valve guides in a BMC A Series Cylinder Head.
I am considering building one using some box section and angle iron with a bottle jack.
I don’t have a bottle jack but do have a 2 Tonne Trolley Jack and thought maybe I could adapat the designs for that.
Anyway, I have found a couple of guides online but does anyone have any ideas to share.
I am also not sure what force I would need?
|Les Jones 1||10/06/2021 22:31:44|
|2227 forum posts|
Is it not possible to draw them in using threaded rod, short lengths of tube and some thick washers ? It is over 50 years since I had an A series engine in bits so my best best guess would be that 6mm is about the largest threaded rod that would fit through the valve guides.
|163 forum posts|
Refer to a BMC service manual. Both the manuals I have to hand - 1957 Austin A35 and 1966 Morris 1100 - state that the valve guides can be knocked out using a hammer and a stepped drift and fitted using the same method. The dimensions of the drift are given, and the hammer shown in the illustrations is not very large - 1lb. perhaps - so excessive force is not needed.
Edited By Redsetter on 10/06/2021 22:48:21
|not done it yet||11/06/2021 06:45:31|
|5944 forum posts|
Had you filled out a profile with your location, there may be someone local to you that may have a press which is available.
I’ve got one and am just going through a couple of A series engines including surface grinding at least one of the heads. I’ve not yet decided whether new guides are necessary but will be checking them out when I can find one of my valve spring compressors! A 948 and a (supposedly) 1000 (but is currently shod with a 12G 202 head).
|john halfpenny||11/06/2021 08:33:34|
|172 forum posts|
They knock in easily with a stepped drift if properly dimensioned, and using a fridge to cool the guides and an oven to warm the head
|noel shelley||11/06/2021 09:27:07|
|567 forum posts|
As has been said MANY times a location would be a great help ! I'm near Kings Lynn and have all you need to do this job. BUT a hammer and drift was the normal way to do this job. To adapt a trolley jack would not be so easy a bottle jack, or hand pump and cylinder would be much easier ! Noel
442 forum posts
A hydraulic press sounds like a good idea to me but I am officially bonkers
|Howard Lewis||11/06/2021 09:46:40|
|4859 forum posts|
You could turn up a suitable dolly, and use 1/4 BSF or UNF threaded rod to pull the guides into place. A thread of that size and pitch can exert a LOT of force.
I am located about 50 miles west of Noel, with the facility to turn up a dolly, and a small 5 ton hydrauilc press.
Where are you located?
A fairly simple frame can be fabricated for use with a bottle jack. (I changed several sets of Ford half shaft bearings with such a set up, before donating it to The WaterWorks Museum. )
There have been articles in MEW about making a hydraulic press, using a bottle jack.
|J Hancock||11/06/2021 09:56:29|
|615 forum posts|
Hammers are very 1960 , I really would persevere with either drawing in gear or, better , the hydraulic jack.
|Andrew Tinsley||11/06/2021 10:03:59|
|1417 forum posts|
Hammer and drift is all you need to remove and insert valve guides, I must have done a hundred or more over the years,
As for advertising even your approximate location on the net. I don't think that is very smart with all the rogues around. That is partly why we have a PM system..
|Nicholas Farr||11/06/2021 11:20:05|
2807 forum posts
Hi, it doesn't take much to make up a simple or temporary press using a bottle jack, here's one I did for compressing the springs on my old Astra front struts.
And here's another for correcting a bit of distortion on a welded part.
Anything that is suitable can be cobbled together, just keep in mind this phrase that I was told by a Blacksmith when I first started working; " If you err at all, err on the strong side. A trolley jack in my opinion, is not really suitable in its own right, because the jacking arm moves in an arc, so the jack would have to positively move freely on its wheels to keep the pressing straight, so if the pressing force is not too great, the friction on the wheel bores may be too high for them to turn and if your pressing goes out of being straight, all sorts of things can go wrong, the worst one being the part pinging out like a projectile from a catapult and hitting you and causing real harm, I have seen it happen with the smallest of things.
|Phil P||11/06/2021 12:25:05|
|780 forum posts|
I just popped down to my local garage and they were more than happy to let me use their 10 ton press when I did my own Morris Minor head, I just made up a stepped mandrel to use as a tool under the press.
A few packets of biscuits was accepted in payment, with the promise I could use it anytime I need to.
|Mike Poole||11/06/2021 13:48:52|
2989 forum posts
One of the factors to bear in mind when fitting new guides is whether the fit is correct. Using a warm head and cold guide is often advocated but it’s difficult to gauge how tight the guide is when fitted. I use a threaded rod with mushroom head to locate in the valve seat and wind the new guide in with a suitable adapter to avoid damage to knife edges or seal grooves. Fitting both parts at room temperature gives feedback on how good the fit of the guide is. With alloy heads that have been through a few guide changes the fit can be compromised. Iron heads are less likely to suffer wear to the guide fit. With an alloy head a loose guide can soon make a big hole that will need serious repair work. A press is a handy bit of kit to have in the workshop but it is not essential for valve guide removal or fitting.
|163 forum posts|
It will take half an hour to put the guides in with a hammer and a drift.
It will take all day to make a satisfactory hydraulic press - assuming you have all the materials and skills to hand, which the OP clearly hasn't - and it will still take half an hour to press the guides in.
Either way you will need the correctly sized drift.
Why then would you do it the slower and more complicated way? Life is too short.
If you want to make a press for its own sake, fine, but what the OP really wants to do is replace his valve guides.
Edited By Redsetter on 11/06/2021 14:06:04
|old mart||11/06/2021 20:09:01|
|3062 forum posts|
I would make the drift out of a bit of brass bar rather than steel.
|larry phelan 1||12/06/2021 17:03:33|
|1030 forum posts|
I bought a 5 ton bottle jack in Aldi,s for very little money. Surprising how useful it has proved to be, and it eats nothing !
|not done it yet||12/06/2021 19:47:09|
|5944 forum posts|
I expect a good big vise could be used with appropriate support and packing, if used carefully by someone sufficiently skillful.
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