12 replies to this topic

[gazza82]

Apart from the obvious difference (collets) is anything else different between one and three groove valves?

 

I want to replace the springs that came with my second-hand head (painted red by the way ... so think it's an A+12G940 unleaded ... sold as such).

 

I plan to fit double springs but are the spring caps different before I look at whether to upgrade/replace them too? It will be with standard rockers (I've got a set of both pressed and sintered at the moment) but something like a 276 cam. It's not a track car, but I'm assuming it will get red lined occasionally (1330cc).

 

Any other advise and wisdom welcomed!

 

TIA!

 

 

 

[ACDodd]

Triple collets are designed to leg the valve rotate during use. This is good for road engines as it reduces the effects of wear on the valve seats. Single groove collets are designed to stop the valve rotating and are more suitable for high lift high rpm applications. For stock rockers and road use stick with the triple groove setup. Use minispares 525 double spring set. 526's too much for your application.

Ac

Edited by ACDodd, 09 April 2014 - 06:29 PM.

[carbon]

Also my understanding is that the collets and retainers have slight differences between single and triple groove type?

 

I don't think you can mix and match, others may be able to confirm or deny this.

[yeti21586]

my inlets are single groove with clip and my exhaust are tripple grooved ones

[carbon]

Yeti - is that a small bore head you have? Sounds like you may have the old 'square groove' collets and some triple groove.

 

I think as long as the old collets are kept with old retainers and the triple groove ones use 'triple' retainers this should be OK.

 

Reason for saying they should not be mixed up is that I believe the taper angle on the collets might be different, but I am not 100% sure on this as I have never used any triple collet valves.

[yeti21586]

yeah its a 1098 12g206 head

[gazza82]

Also my understanding is that the collets and retainers have slight differences between single and triple groove type?

 

I don't think you can mix and match, others may be able to confirm or deny this.

 

That is pretty much what I need to know. I'm assuming the retainers are the right triple ones but how to tell? Is there a visual difference?

 

Ac thanks for the tip on the springs ... I'm pretty sure they are the ones I have on my MS shopping list! And thanks to TMF+ I should be able to save a few pence with the club discount

Edited by gazza82, 09 April 2014 - 06:27 PM.

[ACDodd]

Yes you must not mix keepers and retainers.

Ac

[gazza82]

Minispares list several sets of spring top caps, some are clearly marked as only suitable for single groove collets and one set is clearly for triple collets AHU1897, but one says it is OK of r double springs but doesn't say what collet type (AEA653). And as it only shows the underside, I can't compare the top!

 

I'll drop them a line tomorrow and ask ... but it looks like the AHU1897 are the ones to use or to use to compare mine with.

[gazza82]

Quite update.

 

Triple valve caps are AHU1897, so I'll compare them to mine. As the collets seems to seat OK then my caps should be suitable. They are fine with double springs and MS recommend the C-AEA654 inner collars with C-AEA525 double spring set.

Edited by gazza82, 10 April 2014 - 03:30 PM.

[gazza82]

Mine look same as MS pic ... happier now!

[carbon]

As with most topics Cooperman was here before... http://www.theminifo...s-and-top-hats/

[gazza82]

From my investigations there are thicker exhaust valves so there are caps with larger holes too.

I ran a search before posting ... but it came back with a very large number of results ... I'd still be reading. Next time I'll add "cooperman" to the mix