Making cast iron valve guides

[cardiffrob]

Hello.

I've searched through the inteweb a bit looking for info as to which material bar I should buy to make some cast iron valve guides for a vintage car. The valves will have new chrome-plated stems so I can use the same sort of material that has always been used on cars, so long as I can find what that was. The closest I've got is that it is "Grey Cast Iron" but no further.

Any ideas as to what I need to order? Is there a specific product I need to find? OD needs to be in the order of 5/8 inch and about 1 1/4 long with the ability to take 7mm or 9/32 inch valves. Any suggestions?

Thanks

Rob

 

[500e]

Morning Rob
Never used chrome valves i remember Ivy's early problems with chrome, have tended to use Nitrided this gives allover hardness & I personally thing better wear with unleaded fuel either bought from Paul Ivy
Kingswood Farm
Kingswood Road
Albrighton
Wolverhampton WV7 3AQ
Tel
+44 (0) 1902 373770
Fax
+44 (0) 1902 373772

OR for guides
GSValves@aol.com
https://www.goodson.com/Universal-Cast-Iron-Valve-Guides/
Have only heard cast called grey cast iron guides
Wandering through net found this from Mahle
https://www.mahle-aftermarket.com/m...alve_train_components/einbauempfehlung_en.pdf

 

[rtbcomp]

I believe cast iron has self-lubricating qualities, so I'd stick with that.

I haven't any experience with chromed/chrome alloy valves, but the Perkins Diesel engine manual states not to use chrome rings with chrome liners.

 

[Gritineye]

Where guides fitted originally or did the valves run in the cast iron head?

I've got a similar job to do and I'm looking at fitting valves with a thicker stem than original and reaming the head to suit them.

 

[doubleboost]

I remember with mini race engines you could not use the S valves (nimonic steel) with cast guides
You had to use bronze or they picked up

 

[cardiffrob]

In some of the blurb it says that Grey Cast Iron will work with steel and stainless IF they have had the stems hard-chromed to prevent nastiness. Bronze (Manganeese and Si/Al Bronze) will work with other materials without the need for the hard-chrome plating. The valves I have my eye on (from Paul Ivey etc) can come in any blend of materials but I'm looking at chromed stems so I can reuse the 6 surviving cast iron guides and add 2 brand new ones, so long as I can be certain about the spec of the cast iron. In the link 500e sent it suggests...Grey cast iron alloy with perlitic microstructure and good wear resistance. For applications with normal loads. Bog standard soft Grey Cast Iron? If so, where can I get some 3/4 inch bar????

 

[Cobbler]

Could you find some standard valve guides that have enough meat on them to allow machining to the size you need. I've got some Rover V8 ones in the shed, I'll measure them tomorrow to see if their anything close.

 

[doubleboost]

In some of the blurb it says that Grey Cast Iron will work with steel and stainless IF they have had the stems hard-chromed to prevent nastiness. Bronze (Manganeese and Si/Al Bronze) will work with other materials without the need for the hard-chrome plating. The valves I have my eye on (from Paul Ivey etc) can come in any blend of materials but I'm looking at chromed stems so I can reuse the 6 surviving cast iron guides and add 2 brand new ones, so long as I can be certain about the spec of the cast iron. In the link 500e sent it suggests...Grey cast iron alloy with perlitic microstructure and good wear resistance. For applications with normal loads. Bog standard soft Grey Cast Iron? If so, where can I get some 3/4 inch bar????

Paul Ivey that is a name from the past lol

 

[BarrieJ]

Is there any value in trying a foundry Rob? Still several left in England, not sure about Wales; casting grey for all sort of uses, might one of them already produce something close enough to be machined to your requirement?

http://www.bridportfoundry.com/p/iron-castings

http://www.wbwhitefoundry.co.uk/

http://www.kilnerhutchinsonfoundries.co.uk/

http://www.smallcastings.co.uk/

 

[doubleboost]

http://www.ebay.co.uk/itm/25mm-appr...176642?hash=item3d360314c2:g:iLMAAOxyYTRSUwLM

 

[Rocketman]

I believe cast iron has self-lubricating qualities, so I'd stick with that.

I haven't any experience with chromed/chrome alloy valves, but the Perkins Diesel engine manual states not to use chrome rings with chrome liners.

Nitriding also reduces the friction factor of the normal base material. It also even with the same material one nitrited and one not gives the same characteristics as using dissimilar materials to reduce wear. So in theory you could use the same material running with each other - one being nitride and one being hardened without binding problems.

 

[Cobbler]

Could you find some standard valve guides that have enough meat on them to allow machining to the size you need. I've got some Rover V8 ones in the shed, I'll measure them tomorrow to see if their anything close.

Rover ones are out Rob, the stem dia is about 8.6mm measuring quickly. Might be worth looking at A series ones, you could sleeve the outer diameter if it's too small. No idea about the dimensions, but sounds about right, I haven't had one apart for years though......

 

[cardiffrob]

Thanks, everyone.
So far I have found the closest to be Vauxhall C20XE guides and Ford YB (?) for standard guides that could be machined down but they are both a little small on the outer diameter and won't hold the inner springs in place. You can just see the 'collar' in the pic.
Is Meehanite the right stuff, then? If so, I'll get some of that.

 

[500e]

Spacers were a fairly standard thing to hold inner springs also to stop wear on alloy head by both springs "top hat without crown"
Paul Ivy still about as a company not dealt with race cars for a few years but think they morphed into GS valves not the same address though
You still resurrecting that Climax motor Rob

 

[cardiffrob]

Strange that there are no steel seats for the outer springs. Might be worth slipping a small washer there, I guess. GS Valves are the most helpful candidates as supplier so far.

Close, an ALTA. Having to fit it in with various days in the Sim, getting killed several times daily. Today the guy didn't manage to land on the tarmac one single time. Not too good for someone with an Instrument rating and a commercial licence!!!!!

 

[500e]

We see them come in for service as well, some are really the ones doing towering take off with full fuel & all seats occupied when no need scare the living daylights out of me, where to go if eng failure

 

[cardiffrob]

where to go if eng failure

Straight down into the middle of the impending fireball?

Anyways, I've ordered myself a piece of Meehanite rod since I found that TVR use it for chromed stem valves, so it must be acceptable. Fingers crossed!

 

[brightspark]

Straight down into the middle of the impending fireball?

Anyways, I've ordered myself a piece of Meehanite rod since I found that TVR use it for chromed stem valves, so it must be acceptable. Fingers crossed!

mehanite is a quality close grained iron and will suit the job perfectly easily Machinable and wont have hard spots in it. the foundry near use used to cast it for high spec items

 

[Rig Pig]

Collage engineering supply sell CI bar in a variety of shapes and sizes.

 

[cardiffrob]

First one made. Size worked out ok but the biggest issue I have is getting the hole parallel to the OD. What is seen to be the correct way/professional way to get the hole drilled straight. I'm new to this machining stuff. It wandered off by maybe 15 thou?

By the way, Meehanite machines nicely.