13 replies to this topic

[TopCatCustom]

Hi, just thinking out loud- how important is the weight in cam followers? I'm trying to save weight everywhere and the valve train is no exception, but I can help thinking that no matter what cam followers you use- won't they just sit full of oil anyway?

The Isky followers are lightweight for example, have the oil hole but there is no way oil is going to drain out at a few thousand rpm, and the taller design just means that more oil can sit in them surely? I know it may be thrown out to some extent but there may also be some vacuum pulled by it trying to come out vertically- like trying to get jelly out of a mold but obviously quite exaggerated!

Has anyone else had any thoughts on this?

Also is there anything to worry about with the oil hole on good followers like Isky ones?

[johnatandy]

The good followers with the oil holes are not a problem especially isky ones.

I have allways gone for the taller followers as they seam to be more stable at high rpm, with regards to lightened ones, it would not do any harm using them as the heavy ones are filled with oil too so they will still be lighter than the heavy ones

Maybe composite pushrods? if you are trying to get the weight out of the valve train.

Why do you want to lighten the valve train (increase RPM?)

John

[Dan]

Oil is considerably less dense than iron! Although they do drain because followers don't just rattle up and down, they spin round fairly fast which keeps the oil moving through them. Taller followers are indeed more stable, some engines that were contemporary with the A series were designed with quite short followers and they can actually turn sideways in the bore and jam.

[MRA]

We only lighten the solid followers, as the hole can be the source for a crack to probogate.

[TopCatCustom]

I forgot about them spinning as well- so the drain hole- is it intended to lubricate the sides of the bore or to allow drain back? They can't be a tight enough fit to warrant lubrication holes surely- so perhaps not needed, though taller followers must almost eliminate the risk of cracking due to more material.

Martin, have you weighed your lightened followers and do you know the isky weights?

[MRA]

Standard = 50g - standard and high performance use
light = 40g - high performance and race use
ultra light = 30g - Short duration drag race etc.

[Cater_Racer]

Hi C4NNON, I'm using the KENCF95's the're fine.

Dunno the difference from standards, but seem to be problem free .

by the way still on for Brands...............

[Ethel]

All valve train weight has a big effect, it's reciprocating so accelerates from stationary and back twice for every valve opening. Apart from the extra friction you also need to compress the stronger springs needed to accelerate it all fast enough to keep up with the cam when the valve closes. Spin or not, precious little oil will manage to keep in the saddle of a bucking cam follower.

[TopCatCustom]

I was ordering some stuff so got a set of isky ones whilst I was at it, I like the tall design and a well reputed company

thanks for all the input on the thread!

[MRA]

The Isky followers are no taller than a standard Mini follower....

Also take a look at the main gallery closest to the followers you will see that the followers are fed with oil under pressure.

[TopCatCustom]

The Isky ones weigh 39g and are just shy of 41mm tall, couldn't find any standard ones to measure!

[liirge]

Original and ISky, the Isky ones are indeed taller!

[TopCatCustom]

Well done that man!!!

[liirge]

My Pleasure!