Let find me a cam!

kiwicar · Post by **kiwicar** » Fri Mar 23, 2007 4:11 pm

The buick V6 is the 215 v8 with 2 cylinders chopped off and very dodgy crank to make it even fire, appart from that it is basically the same deal, tappet bore, headbolt pattern, valve train (rockers, valves etc) and tappets. (Please correct me if I am wrong here but in this case I believe I am right) they developed the V6 for several classes including as an indy 500 engine with a turbo on it the size of a washing machine running methanol.
Your other route is to bore out the lifter bores to fit SBC size tappets and use small block chevy mechanical roller lifters then get a buick blank ground with a SBC pattern (comp do about 3 base circle came patterns for the SBC one of which would do you) again ask them about their "custom grind" service or choose a ford/mopar/AMC/Buick 300? cam pattern with an appropriate base circle.
Mike

ihatesissycars · Post by **ihatesissycars** » Fri Mar 23, 2007 4:20 pm

Oh well then!

After some thought this has going to have to be a hydraulic cam as its just too much agro to take the rocker covers off my engine (requires trumpet base and fuel rail removal!!!!) so what is the silliest hydrualic cam we know of?

ShortRound · Post by **ShortRound** » Sat Mar 31, 2007 12:06 am

ihatesissycars wrote:Kiwi, roller cams aren't available for rovers i believe?

Russell, how ofter do you need to adjust yer tappets with your present cam? What are you using to adjust them? Adjustable pushrods or rockers?

Hiya,
Not sure if I completely understand the term 'roller cam' but is this what you mean? Take a look here...
http://www.v8tuner.co.uk/product.php?id=533

HairbearTE · Post by **HairbearTE** » Sat Mar 31, 2007 2:10 am

That is a roller rocker set. A roller rocker is defined by the actual point of contact of the rocker arm with the valve tip being a roller wheel as opposed to a solid contact patch (as is the case with the standard set up.) A roller cam is a cam designed to work with a lifter that features a rolling wheel as its contact patch as opposed to a flat surface like a regular lifter. The roller in the lifter allows the camshaft to be ground with a more severe opening and closing rate than is practical with a flat tappet camshaft. A roller cam for such an application will appear vastly different to the naked eye in as much that the lobe of the cam will appear much 'fatter' than the equivalent cam ground for a flat tappet lifter. A roller cam can operate faster opening and closing of the valves than a standard cam but it needs a higher pressure from the valve spring in order to operate and keep the lifter in contact with the cam at these higher rates of lift acceleration. This should not be confused (as it sometimes is) with a cam using roller cam bearings instead of normal cam bearings. A roller cam bearing is a bearing that features thin needle rollers within the bearing that the cam rides on, thus vastly reducing friction within the engine in this area. Have a look around the comp cams website for example to see examples of roller cams and lifters. Some rover V8's have been built with custom roller cams but to do so is expensive and it is not common.

Robrover · Post by **Robrover** » Sat Mar 31, 2007 8:23 am

I'm using a Crane 218 in my 4.6. Great road cam, plenty of mid range torque. Idles well in traffic too, even with the bv heads and 4 barrel carb. My SD1 weighs around 1190 kg (f/g panels, perspex rear screen, etc).

Rev_erend · Post by **Rev_erend** » Thu May 31, 2007 2:51 pm

ihatesissycars wrote:Kiwi, roller cams aren't available for rovers i believe?

Russell, how ofter do you need to adjust yer tappets with your present cam? What are you using to adjust them? Adjustable pushrods or rockers?

Ian Richardson (Wildcat) has quite a few 'Roller Cams' for RV's in his store room .. I've seen them.

But they are for radical engines.

I myself have a 248 Mech (V8 dev 404 .. same lift and duration and also made by Kent cams) and it drives very nicely.

It did need to be mapped very finely by Mark Adams to get over a very shunty delivery low down though..

This cam table is useful for comparison :
http://www.btinternet.com/~jon.wolfe/kentcamdata.htm

Ian Anderson · Post by **Ian Anderson** » Fri Jun 01, 2007 6:30 pm

Gav

I've got a JE102 in mine and said t have loads of overlap and 0.5 inch lift

Hates running 1600 - 2100 rpm but pulls like a train otherwise

It looks like a good weekend weatherwise - want a spin to feel the power? I could meet you harf way to AAAAAMpshire! - I;m at J1 M3

Oh yes and the car is 1100kg and we could be really silly and put the JE modded ECU back on for a load more ponies!

Ian

ihatesissycars · Post by **ihatesissycars** » Fri Jun 01, 2007 7:13 pm

Thats a very tempting offer Ian but i've got a full schedule this weekend with my car, I'm in the process of tying up all the odds and sods to finish my car so that when i get my v5 back i can tax the bugger! Thanks again though!

kiwicar · Post by **kiwicar** » Mon Jun 04, 2007 1:56 pm

Hi Hairbear TE
do you know anything about expected service life of roller bearinged cams?
I have only heard of this set up on race engines, however that includes NASCAR use, so I assume they are good for 500 miles at 80 to 100% full throttle so they must have some life (and a guy last year was selling an endurance race chevy engine on racecars-direct with one in).
If you have any info I would be very interested in it.
Mike

HairbearTE · Post by **HairbearTE** » Mon Jun 04, 2007 10:06 pm

Hi Kiwi, no I dont have any idea how many miles you could expect to get on the street out of a roller cam bearing set-up. As you know moving engine parts are supposed to ride on a thin film of oil and not in fact touch the bearings during operation but in reality this is impossible 100% of the time and inevitably there are loads placed on the bearings or they would never be any wear and tear. Stresses on the cam can be minimised by using the crank driven oil pump set-up (or an external system) and ensuring that the chain tension is correct but the force of the valve springs alone in this kind of engine (you'd hardly be running a soft cam) would be considerable. The thing is, because this is really in the realms of the serious racing engine, and serious racing engines get rebuilt on a regular basis, I doubt that there is much data available re the longevity of such a system on the street! I am told that some of the engines that used to race in the rover V8 challenge drag racing series used roller cam bearings so if you can track down any of the competitors they might be able to advise. John Eales and Ian at Wildcat will both have built rovers with roller bearings at some stage and would be the ones to talk to. Real Steel built the engine for Kev Jenkins rover drag car a few years back and that probably had roller bearings so they might be able to advise. The bearings themselves are available from a company called Tyco I believe. Keep us posted if you have a go at building such an engine.

Mark · Post by **Mark** » Mon Jun 04, 2007 10:27 pm

Roller cams should last longer than flat tappet cams regardless of application, my strangled weedy 150bhp Ford 302 has a roller cam

Why Ford bothered I do not know but it does save on wear and tear.

From what I've read it is hard to get the spring poundage to controll a high performance roller cam in the Rover engine

IF you have a friendly MOT man get a Kent M238

I had one in a 4.5 Rover/TVR engine and is was very tractable, it also helped towards 333bhp/320lbsft.
Unburnt hydrocarbons were around 4200 PPM at idle with a 450cfm Mech Sec Holley and Harcourt inlet

The law states that the MOT man can re-test at 2000rpm and it just got through

Mark

kiwicar · Post by **kiwicar** » Tue Jun 05, 2007 9:51 am

Thanks Hairbear
I shall ask around further, I am building a chevy rather than a Rover so will ask what contacts I have about this combination, I am going to be running a 5 port dry sump set up with a belt drive to the cam, mech roller set up (comp 287TKR-6 but on 112 LSA) and want to run the top end as dry as possable, with oil stand offs in the valley and a roller rocker set up so the roller beearing cam bearings would be a good idea on this front (and I generally like the idea of reducing friction and therefor heat!).
Mike

HairbearTE · Post by **HairbearTE** » Tue Jun 05, 2007 9:34 pm

I've got a set here that were intended for a SBC that has had its block modified to accomodate. The outside diameter is 60mm and the inside is 55mm (a popular oversize for cam journals on racing chevys). There just isn't enough meat in a standard rover block for me to feel comfortable about using them. Another style of roller bearings is available that are encased on the outer of the bearings but the external diameter is larger still for any given inside diameter.

kiwicar · Post by **kiwicar** » Wed Jun 06, 2007 8:17 am

Thanks Hairbear much apreciated
Those are small bearings! 2.5mm. I will have another look at the comp cams website and see what size roller bearing cam's they do and talk to the people Ill get to prep my block and see what they think. I am building this for a car I don't expect to do more than 3K miles a year in so if it works out as a strip and replace every couple of years it may be practical, not sure In need to know more.
Mike

ihatesissycars · Post by **ihatesissycars** » Thu Jun 07, 2007 10:34 pm

Errr there's mention of a rover roller cam in this link.

http://www.triumphroverspares.com.au/html/v8.htm