The V8 Owners Forum -

ged wrote:Avgas, now that brings back memories.

Doesn't it just... I used to fill up at the pump on the apron back when I was an apprentice. Was very bent out of shape when the company sold the pumps to another crowd and they put stop to it.
On weekends there was a queue of Porsches, Ferraris and various boats and bikes waiting to fill up.

Then the Taxman put the brakes on that one...... bah!!

No one knows anything about Merlin Heads because no one can get them. Beenn trying to get a set from RS for 5 years!

This 4.9 TR8 made 391 hp using JE Stage 3 heads, roller cam, 650 Holley/Harcourt and Mallory dissy

http://thebritishcar.com/showthread.php ... eet-inside.

I dream of roller rockers and a roller cam... Can these be obtained in the uk?? Do you think it is this that made all the difference?? Lift velocity so much higher I suppose. And they look so good:-)

I've got a set of the Kenne Bell roller rockers,with the heavy duty shafts and steel posts with outriggers !
They look so sexy,I should have glass rocker covers !

Hi
To do a roller cam on a rover he easiest and cheapest way over here is to use Chevy aftermarker roller tappets (link bar type), chevy push rods, a Buick 215 blank (in steel) with a suitable cam profile ground on it (from someone like Comp cams or Iskydine in the states) and you need to do something about the timming chain. Valve springs are just a case of finding the right ones in someones catalog.
On one of the american rover V8 sites they are keen of using modified chevy "dog bone" type lifters. . Hovever that is because in the states they have scrap yards full of the things in Chevy vortec engines and they go for pennies used. If you want to go that route then you end up buying new and as the shipping is the same for both sorts, the factory lifters new and not very much cheeper you then eng up having to have the "dog bones" made and end up spending about the same money for an inferior set up.
Best regards
Mike

kiwicar wrote:...use Chevy aftermarker roller tappets (link bar type)..

Are the Chevy lifter bore sizes the same so that the link bars have the correct spacing and slot suitable for lift?

IMHO forget the factory fit link bars & get rollers that have 'clip on' link bars, at least then you can make up the link bars to suit.

I have chevy hydraulic lifters in the Escort so i guess the lifter diameter is the same as Rover ??

mgbv8 wrote:I have chevy hydraulic lifters in the Escort so i guess the lifter diameter is the same as Rover ??

It's not the .842" lifter bore thats the problem, its the spacing between the lifters and the lift that defines the link bar length & slot length. If they are not correct the articulation will not allow you to fit the lifters in pairs.

spend wrote:

mgbv8 wrote:I have chevy hydraulic lifters in the Escort so i guess the lifter diameter is the same as Rover ??

It's not the .842" lifter bore thats the problem, its the spacing between the lifters and the lift that defines the link bar length & slot length. If they are not correct the articulation will not allow you to fit the lifters in pairs.

OK!
You mean those funny bars that Kiwi has on the Slingshot engine
I understand now !

Hi
When I had my engine apart the time before last Reg (r2d2hp) borrowed a pair of lifters and tried them in his Rover block, I am pretty sure they fitted ok (Link bar wise, I know the bores are the same!)
Best regards
Mike

Hi Mike,

From my untrained eye they looked fine to me. There was no binding of the link bar so to use we would have to have a roller cam made and work out some mechanism to apply some pressure to hold them against the cam.

If Phil is getting a custom cam ground for supercharger use the maybe we could look at getting several done to reduce the cost.

Regards
Reg

"work out some mechanism to apply some pressure to hold them against the cam. "

I think the system is called pushrods, rockers and valve springs ??
Best regards
Mike

ha ha Mike,

Don’t you have some sort offspring assembly that hold the roller followers against the cam. You would not want then bouncing when using adjustable rockers and tappet gaps.

Guess an option would be to use hydraulic roller followers

You sometimes see springs between the underside of the head and the lifter, that's old technology, called a rev kit in the days when modern valve springs weren't available, also known as a helper spring. You don't want to float the valves with a roller follower but nowadays they just run a whole bunch of spring pressure up top to achieve the same result.

Alan