Valve locks/Spring retainers

[moodoo]

Maybe a stupid question...

I have a CIH head with 8mm inlet valves in it. I need some valve locks and matching spring retainers for it. The valves have a single circular groove in - so once I get corresponding valve locks, and a set of spring retainers with the same locking angle, is there anything special I need to look for?

I mean, is there any difference between spring retainer A, vs spring retainer B etc? Anything to watch for?

Thanks,

Fin

[Jessopia74]

Not sure if you are wanting custom setup?

So long as they retain the spring properly, then it’s five to pretty use and caps & matching collets. You can also use different springs too if they better match the spring seats. 
The most obvious place that has a world of options would be something like https://www.summitracing.com/search/part-type/valve-springs , but I do recall Volvo springs was an option many moons ago as an upgrade. 

 

[moodoo]

Thanks Jess. No, nothing custom, just off the shelf is fine, using standard valve springs...just didn't know what, if any, were the difference between different brands/types of retainers and locks.

[Jessopia74]

4 hours ago, moodoo said:

Thanks Jess. No, nothing custom, just off the shelf is fine, using standard valve springs...just didn't know what, if any, were the difference between different brands/types of retainers and locks.

Ah👍 Well the spring seat and collect should sit at the same height once on the stem. You can dummy them up to check, but if your not building a race engine with extra lift/duration (camshaft ramp slops can be pretty vicious) then I would not worry if they all look to be same 

[moodoo]

Ok...I am planning on a slightly uprated cam, but not anything too ‘race spec’!

What do you mean by sitting at the same height? You mean across all valves, intakes and exhausts? Or just that on a given valve, the lock/collet height should match the spring retainer height? I was going to use standard cih ones on my standard diameter exhaust valves, I just need to buy a set for the 8mm stem intakes.

[Jessopia74]

Springs are rated at a given compressed length. They need to excerpt a certain force when the valve is closed to be effective. The also need enough usable range so that they don’t break or go coil bound. So if you want to use some original springs, you need to make sure that the new caps and collects put the spring in roughly the same position (give or take ). It’s easier if they make the springs to be under compressed slightly as you can make shims to put between head and spring, but if they are too compressed (sat lower on valve ) then you want to be changing to a different spring.

you could use the whole standard assembly if you have some tapered inserts made to fit inside the cap that matched for the ones you need to fit your 8mm valve stems. Or just have some made to suit. I don’t think I have ever seen specific catalogue for collets with sizes, but perhaps a specialist might be able to supply exactly the right sized collets - not sure. 
 

[moodoo]

Ah, yes, I understand now Jess...thanks very much for the advice!