Lifter bores
Turbo Mini Forums

I know there are race cams around from the likes of newman, elgin, Russel Engineering etc that need to use larger diameter followers (around .87") has any one on here ever taken the litfer holes out larger?

Or failing that if any one has a bare block handy could ther measure the centres between a coupe of lifter bores.

Pretty please!:)

I can have a look tonight if you don't have any luck beforehand.

In the 13's at last!.. Just

Top Man!

8-)

do you mean how much meat is between the centres? or from lifter centre to centre.

Just had a look at the block in the front room and It looks like a random hole between two of the bores would dictate how big it could go.

On the subject of the random holes, they are the oil drains and the wall thickness between the hole and follower hole is about 4mm. Thats guess work though because I can't get anything in there to measure it.

cheers thats good info, i forgot about the oil drains.

from the sound of it it may be possible to go to about .9"

my nitros am profiles produce big lift but i am still using the standard follower

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I cant understand why if a 310 uses standard followers anything else would need bigger ones unless its had a dodgy regrind

Paul

I seriously doubt it!

Even my piper 320 with its crazy .455 lift uses standard followers,

out of curiosity why do you want to use bigger followers if its to run more lift you will be limited by the cam bearing Dia.

and if its to run roller cam followers you will be caught by the max possable depth of the follower housing.

I seriously doubt it!

the acceleration is limited by the diameter of the follower. not the lift.

That sir, is not rust, it is the progressive mass reduction system

http://aseriesmodifications.wordpress.com/

Well I have a 1600 ford motor which was worked by Holbay it has some yank V8 roller followers they are only 0.672 in dia but are over 2.3" long,
I had taught of turning them down but at the end of the day you then need to get a special ground cam, shorten push rods ectra,

I was also told there not stable under 2" not sure how true that is tho.

such large and heavy things seem a bit odd for improving the performance of a reciprocal system.. it is not like you need 1.5 inch lift like on a yank V8. I would guess that all that mass starts to live a life of it's own at high rpm (?)

That sir, is not rust, it is the progressive mass reduction system

http://aseriesmodifications.wordpress.com/

100% correct Sir Yun that is why I never bothered with them worked standard followers seem to live well to 8500 rpm so why change.

because the bigger dia meens you can have a more agressive profile on the opening ramp,

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I'm going to have to thing about that, my brain isn't fully working this evening.

Ok, the bores are 20mm. The outer pairs have 11mm between them. The inners have the oil drain which is 15mm and has about 3mm of meat between.

In the 13's at last!.. Just

cheers Gary.

yep i'm looking at fitting roller lifters, actually I have been looking at it on and off for a while now.

It would be pretty easy to do with an S block, but the cast tapet chests of the later blocks cause a real headache.

yes std followers work at high rpm but for how long? what i'm looking at achiveing is a shortish duration high lift cam that will live on the road, ie not wear out in traffic. How long will a piper 320 last at tickover before it knocks all the tips off the lobes?

anyway just beacase somthing works thats no reason not to look at improving it lol.

I think i have finally found a production lifter that is short enough to go into the a block.

Rob H, with a cam and solid follower you can onlyso agressive before the edge of the follower digs into the cam and it all goes crunch, if you enlarege the follower you can go to a hotter cam.

the upper limit on the .81" mini follower is abput 7 thou per crank degree. somthing like a K1100 cam with its larger follower can go to around 12 thou per degre IIRC.

Good work Joe. I know you have been thinking about this for some time.

In the 13's at last!.. Just

Its something I was looking into a couple of years ago but it would have taken a lot of work to make sure the follower didnt rotate in its bore - I couldnt be bothered in the end

Paul

I seriously doubt it!

yep,

about the only solution is a keyed follower, i was looking at the Jesel ones that come out of nascars with test miles on them, but they are generally .937" ie too big.

Same as what I was looking at with a view to having Jesel make custom ones if test went well enough.
It was the hassle of fitting a key in the bore that I couldnt be bothered with as I was going to try marketing it but its not just a straight forward mod

Paul

I seriously doubt it!

Joe,
First off the Piper cams iron cam followers are some of the best on the market, I have in my work shop as we speak a race engine that has had these fitted with a Kent 310 and my own 1.625 roller rockers as well as running 260lb valve springs this engine was turned to 8500 rpm for a full season well over 25 hours and these followers are in as new condition with only minimal bed in wear.

When I started looking into roller lifters 3 or 4 years ago now (forgive me if my memory dose not sever me well on this)

I found the lightest roller lifter I could get my hands on was some 12 grams heaver that a good chilled Iron follower. and in excess of 2" long and and something in the ball park of .7" or.8" in OD which just wont fit in a A+ 1275 block with a cam with any lift.


I would never contemplate putting a 320 in a road car it just would not work not with roller rockers or Harry potters magic wand


If your interested I will E mail you a word doc I wrote on this at the time with all the options I tried and all the info I amassed at the time It might help you get further than I got.

best of luck with it Joe and keep us up to date I'm very intrested to see how you get on :)

Edited by PaulH on 21st Jul, 2009.

Yup came up on this problem there is however a very simple salutation to this I’m happy to E-mail or PM to anyone for obvious reasons I ant putting it into words here but there is no key needed