Valve Guides, Geometry Etc

topcatcustom · Post by **topcatcustom** » Mon Mar 30, 2009 9:15 am

Thanks Perry, all this head stuff is starting to get me in a muddle now! I don't mind measuring and bolting stuff together but this is getting more and more complicated!!! The main thing is that the preload (and other factors) does not offer ANY chance of holding one of the inlet valves open and risking a backfire- the volume of fuel/air in the blower & manifold is potentially a bomb and I don't really want to rely on the little backfire valves!!!

topcatcustom · Post by **topcatcustom** » Sat May 09, 2009 8:05 am

Valve to piston clearance seems fine- the heads have not been skimmed and using composite gaskets so was hoping there wasn't going to be a problem there!

However the 1 or 2 high valve stems (due to seats cut further in?) are going to cause a huge amount of lifter pre-load, like I said there is only 1 or 2 but not ideal. Should I just set the majority right with the shims I have or do I need to use adjustables? (Still dont fancy adjustables with the very fine thread working against double valve springs all day long!)

The other option would be to grind a few thou off the end of the high valve stem- ever been done before?

Would be nice to get this sorted as can finish the engine then!

TC

kiwicar · Post by **kiwicar** » Sat May 09, 2009 3:06 pm

Grinding the ends of valves is common practice, normally done when using a hardened valve cap so to get over the fact you have removed the hardening off the valve stem with the grinder. you need to do it without heating up the stem or you make it too ductile. Really it is a bodge as you should have the valve seats the same height as, if you don't the ports are flowing different amounts, but in a rover it probably won't notice.
Mike

topcatcustom · Post by **topcatcustom** » Sat May 09, 2009 6:08 pm

Thanks Mike, however after bolting the heads down today and making up the rocker shafts the stem heights look pretty good bar 1 which is slightly out- and it is an exhaust so not too fussed. The problem is- the pre-loads are all over the place

I put the 50thou shims in and pre-load varies between practically 0 to 60thou.... do I have any option but to use adjustables? Btw my rocker shafts are new, as are all the rockers and everything!

TC

kiwicar · Post by **kiwicar** » Sat May 09, 2009 8:22 pm

rather than adjustable push rods you can get them with only one end fitted so you can cut the unfinished end to length, you need one adjustable to measure the length for each position but they arn't as heavy and are stronger than adjustables.
Mike

topcatcustom · Post by **topcatcustom** » Mon May 11, 2009 10:02 am

kiwicar wrote:rather than adjustable push rods you can get them with only one end fitted so you can cut the unfinished end to length, you need one adjustable to measure the length for each position but they arn't as heavy and are stronger than adjustables.
Mike

Real Steel jobbie?

kiwicar · Post by **kiwicar** » Mon May 11, 2009 2:53 pm

Yup I think they do them, I was thinking Comp Cams or Isky Buick 215, or Summit but I think real steel or try a forum sponsor and see if they can help you.
Mike

mgbv8 · Post by **mgbv8** » Mon May 11, 2009 3:38 pm

Tom
Real steel catalogue page number S1/6 in the Rover V8 section.

http://www.realsteel.co.uk/

topcatcustom · Post by **topcatcustom** » Mon May 11, 2009 4:01 pm

Being part no. AZ500 - the semi finished ones? For an extra £60 I could get adjustables, but noticed these ones have a 5/16 ball on the lifter end which is what the Rhodes lifters are, and of course 3/8 on the rocker end- spot on! Will order a set I think as they must be a lot stronger than the adjustables, and that way I can still use shims to get the geometry right (or mildly better than it would have been!!!)

The arse is that I just spent £40 on the heavy duty ones

but could have been worse, and if/when I do another build I have them spare I suppose... (still trying to look at the bright side of my cock ups!!)

Are they what you run Perry, and do you just cut them down and pop a tadpole shaped thing in the end?

TC

CastleMGBV8 · Post by **CastleMGBV8** » Mon May 11, 2009 4:46 pm

Tom,

Don't worry it's part of the learning curve.

I ended up using adjustables because I cocked up the reqired length on a set of fixed lenght ones and too much removed, I hadn't measured the required length on every lifter and as you have found there can be variations in valve stem heights etc. After buying a set of adjustables my machine shop said they could have shimmed the 2 or 3 pushrod which were short as there is plenty of length on the tail of the tadpole.

Do double check what size the cups are on your lifters as I have heard of then being either chevy or rover size!

Try an avoid using shims, they do not adjust the geometry only the preload and just make the geometry more wrong!

Assume a red line at 5800RPM unless you are going to upgrade the valve train especially if using doulble valve springs as this puts a lot more stress on the valve gear.

Good luck,

Kevin.

mgbv8 · Post by **mgbv8** » Mon May 11, 2009 5:17 pm

Dont forget to mill the end to accept the little tail on the ball end. There is that little shoulder inside remember!!

I use the full adjustables on mine Tom. Mainly because I knew I was going to be swapping them between a few engines as the last few years went by. That way they can be tweaked to suit most setups.
I still find them a bit of a fiddle to get right, but they do work.

They dont really do any extra work as they still only max out at under 5500rpm as I cross the line. And I've been using the dw050 twin springs for years with them as well.

topcatcustom · Post by **topcatcustom** » Tue May 12, 2009 8:11 am

Cheers guys you are helping me sort this out more rapidly than I would have done! I think my valve train is the same spec as yours Pel, blower cam, Rhodes lifters, Crane DV springs and ret's.
The HD pushrods I got from V8 Tuner and after a conversation with Paul about the probs some of us had found (ball and cup size not matching) he said it would all match as he only bought in proper Rover items. However the ball is too big for the lifter cups- hence why the 5/16 ball would be better! As there is only a push action involved though I thought it was probably not too crucial, and if I remember Perry you said you had only just noticed a while ago that the ball wasn't a proper fit with yours but caused no probs!

Kevin does that mean you have a set of 5/16 "tadpoles"? I think I will end up going with adjustables as (1. It's good to know they withstand your drag'ing and DV springs Perry, and (2. I cant imagine how long it would take with the fixed adjustables to shorten, fit, shorten a bit more, fit again 16 times, especially when it involves lifting off the rocker assembly and bolting it down again for every one, and having to rotate the cam for every one! Think its asking for trouble!

Long post- thanks for the input though!

TC

topcatcustom · Post by **topcatcustom** » Tue May 12, 2009 4:32 pm

Grrr what is it with my bloody timing in buying stuff, went to order the adjustables from real steel and the price has gone from being £146 to £175!!! Damn I can guarantee as soon as I bite the bullet and order some the price will drop or someone will offer me some for cheap. I spent £85 on a pulley for the blower from the states, only to find as soon as I ordered it someone had a BDS one locally for £25.

I am going to go slightly mad and completely insane soon

So- anyone got any adjustable pushrods they want to sell to me for £20

lol

CastleMGBV8 · Post by **CastleMGBV8** » Tue May 12, 2009 6:13 pm

Tom,

To add to your angst although Real steel do the alternitve sizes of ball ends to match your lifters the kit comes with rover size ball each end and you have to pay extra if you require a different size!

I have one set of heavy duty tubular p/rods which I didn't need, one custom set of chrome moly with one end sized for the crane Hi Rev lifters whicih I made 20thou too short!!!!! and a set of adjustables with the additional ball ends to fit the crane lifters.

I don't want to add the cost of that lot up, the only good thing is if I have sufficient valve clearance to use tin gaskets I can use the fixed length custom set and get the comp ratio up around the 10/1 mark.

Kevin.

topcatcustom · Post by **topcatcustom** » Wed May 13, 2009 12:04 pm

Boo, 3 different prices and all about £180 + postage, this aint looking good! How can they have jumped up by £40 when I go to buy them!

Kevin- it appears that real steel give you 2 types of ball end with theirs in the small print underneath?