cam option

[NixVegaGT]

OK I'm waffling on cam choice. I've been looking at the Crower 50233 but I fear the taller lift. Here's specs:
http://www.crower.com/misc/cam_spec/cam_finder.php?part_num=50233&x=0&y=0

Then there is the square Isky 621282 it has pretty good duration but not so sure if the lift is enough:
http://cgi.ebay.com/ebaymotors/_Car-Truck-Parts-Accessories__Buick-Olds-215-300-340-Isky-camshaft-kit-cam-RACE-282H_W0QQitemZ200195955701QQadnZCarQ20Q26Q20TruckQ20PartsQ20Q26Q20AccessoriesQQadiZ2865QQcmdZViewItem?_trksid=p3756.m20.l1116


I don't want to make a poor decision. My project a 5.0L Rover/Buick stroker with 11.5:1 compression. I've built a 750 Qjet for it on a single plane manifold. I could also adapt the Performer and I planned on trying both on the engine dyno. I figured I'll put the redline at 6800. The valves are 1.72 int. and 1.496 ex with 1.6 ratio roller rockers.

Any input is much appreciated.

[NixVegaGT]

OR this one:

http://store.summitracing.com/partdetail.asp?part=CRN%2D890631&autoview=sku

[BlownMGB-V8]

Nick, I don't see a whole lot of difference in those cams except that the Crane has a lower powerband. But based on the duration and lift that could be wholely a function of valve spring pressure since there're no spring specs for the Crane or Isky. They're all three real similar, and you're going to have a wild ride with any of the three.  The lobe profile could be considerably different on all three cams though and without looking at that you really have no way to compare how they are going to act. Obviously a flatter profile with steeper ramps is going to make more power but also need stiffer springs. Plus you've got what, 4 degrees of variation there in lobe separation? I think you need more specifics from each of the grinders.

From my own experience with these engines, you *can* live with the hot cam but you may not want to if you plan to drive the car a lot. In which case something midway between these and stock specs is going to work out nicely and you can upgrade the springs to get into the higher RPM range. But I'd also like to offer one caution. Don't start out with the hot stick and then try to dial back. If you do that, next thing you know you'll be putting a blower on it to get the power back. If that's not a problem I'd lean towards the Isky with the Crower a close second choice, but that's mostly personal preference.

Jim

[hoffbug]

Nic. Dont let numbers scare you.
If you are going with the E-85 Id be tempted to try the Crower cam.. It has basically the same duration and a little higher lift and its ground on a 112 LSA ......that should idle smoother than the ISKY cam with the 109 LSA

[NixVegaGT]

I guess my biggest concern is the lift. I have a Crower 50232 from way back. It's kinda set up for the 215. I figured since I added displacement I'd increase the cam profile.

SO I just went back and checked the lobe lift between the two Crower cams and it's the same at 0.31". My fear about spring bind is gone since I had the heads set up initially for the 50232 anyway. The suggested spring load is the same too. It looks like the only difference is the duration. Cool. I think I'm going to go with my initial thought and go with the Crower 50233.

Thanks for th input, guys. I'm feeling more at ease. Good advice, Jim. LOL! I have a feeling that's what happened to you.

[hoffbug]

So now you have a cam and an intake with no home.. Give me a call before you sell them .

[NixVegaGT]

Cool. I'll keep you in the loop.

[BlownMGB-V8]

Good advice, Jim. LOL! I have a feeling
> that's what happened to you.

Sort of. I put in the hottest cam CC made for the SBB back in about '85 with stiff springs and Rhodes lifters and it was a screamer to be sure. But not knowing the Rhodes are noisy I made the mistake of swapping out a lifter and wiped out that cam lobe so I thought I'd try a different cam. I chose the Kenne Bell one that looked just a half step milder and it just never was the same. Took me a couple of engines before I was back above that power level, one of which was a turbo setup. But it could be just me, I'm well above that point now and it still isn't enough. Not sure why that is exactly, but I do miss the high redline. Starting to think a set of forged pistons might be a good investment and that's a dangerous line to cross. Things just get more and more expensive from there on out.

Jim

[Dan Jones]

> OK I'm waffling on cam choice.

You might want to take a look at the post I made here:

 http://thewedgeshop.21.forumer.com/viewtopic.php?t=71

on cam theory and Rover V8's.  

I ran Vizard's cam selection rules on your engine (3.74" bore, 3.4"
stroke, 11.5:1 compression ratio, 1.72" intake valve) for 75 degrees
overlap (consistent with a hot street motor) and got:

 290 degrees seat duration
 108 LSA
 0.5"+ lift

The lobe separation angle is the important figure here.  If you
want to lower the RPM band, reduce the duration but keep the LSA.
Note that as you go up in displacement, you need to narrow the lobe
center for best performance.  The Crower hydraulic catalog grinds
are all ground on 112 lobe centers, though their solid flat tappets
are 108:

Crower solid flat tappet cams
P/N   Grind  adv dur  0.050   lift       LSA  RPM Range    
50303 282FDP 282/287  238/242 .482/.488  108  2000 to 5500/ redline 7000 300
50304 292FDP 292/298  246/250 .502/.514  108  2500 to 6000/ redline 7500 340
50305 304FDP 304/310  256/262 .536/.549  108  2500 to 6000/ redline 7500 340
lash 0.022" intake/0.024" exhaust

The Isky 282 is on a 109 LSA but Ted at TSI Imported Automotive has
a custom Isky 264 on a 108 but it has a fair bit less overlap (i.e.
a lower RPM band):

Isky  Grind  adv dur  0.050   lift       LSA  
      264    264/264  ---/--- .480/.480  108
      270    270/270  216/216 .470/.470  109  
      282    282/282  224/224 .467/.467  109  

Woody Cooper at the Wedge Shop (thewedgeshop.com) has probably the most
experience in the States with engines like you are building and has a range
of custom Erson grinds he runs in Rover/Buick strokers.  I'd give him a call
and tell him what you're doing and see what he has to offer.  You are giving
up a lot with the 112 lobe center of the Crower 50233.

> Harland Sharp roller rockers 1.6 ratio. COOL!

Did you verify this?  I have it in the back of my mind they were more like
1.55:1 but I'm not sure why.

> I put in the hottest cam CC made for the SBB back in about '85 with
> stiff springs and Rhodes lifters and it was a screamer to be sure.
> But not knowing the Rhodes are noisy I made the mistake of swapping
> out a lifter and wiped out that cam lobe so I thought I'd try a
> different cam.

The Rhoads lifters need the pre-load to be set but the Rover/Buicks have
non-adjustable valvetrain.  The previous owner installed them in my
TR8, along with a Crane H-216 cam.  He used adjustable pushrods to set
pre-load but they were still noisy.  I decided to replace them with a
set of standard lifters but the Rhoads lifters were flat on the bottom,
indicating wear.  The cam looks good but I decided not to chance it and
ordered a new cam.  The old cam was:

 Crane H-216/285-2S-12
 266/278 degrees duration (advertised)
 0.456/0.480" lift
 112 LSA
 48 degrees overlap

The new cam is:

 Erson RV10/RV15 (Wedge Shop custom grind)
 280/288 degrees advertised duration (208/214 @ 0.050")
 0.448"/0.460" lift
 111 lobe separation angle
 4 degrees advanced when installed straight up
 62 degrees overlap

My application is a Triumph TR8 with a stock long block, tri-y headers,
dual exhaust, Edelbrock Performer Rover intake and 500 CFM AFB.  With
only 8.15:1 compression ratio, you can't get too crazy with the cam specs.
The above Erson grind from Woody at the Wedge Shop is one he's found works
well in applications like mine.

Dan Jones

[NixVegaGT]

OK on the cam situation: I called Woody from the Wedge shop. I had a really great conversation with him. He's a like minded guy. What's cool is that he's built a few of these engines and has had a bunch of time to experiment with different profiles.

I ended up going with a cam that sounds crazy radical: Solid lifter, 314 adv dur, and .544 lift. The LCA is 108º. It all sounds crazy but he actually drives a version of this cam with an LCA of 106º and recently got almost 20mpg on a recent power tour. It was a big surprise to him.

There are a lot of factors that make the cam right for the engine: Valve angle and position, Valve to bore ratio, Rod ratio, I'm using 1.6 roller rockers, CR 11:1.

I'll report how it works out when I can finally run the engine. Sounds pretty wicked. Looks like I'm going down the road Jim warned me of. Well I guess we all have to make our own way of it, right? LOL. Thanks for all the advice guys.

[Dan Jones]

> OK on the cam situation: I called Woody from the Wedge shop.
> I had a really great conversation with him. He's a like minded
> guy. What's cool is that he's built a few of these engines and
> has had a bunch of time to experiment with different profiles.

I thought you might benefit from his experience.

> I ended up going with a cam that sounds crazy radical: Solid
> lifter, 314 adv dur, and .544 lift. The LCA is 108º. It all
> sounds crazy but he actually drives a version of this cam with
> an LCA of 106º and recently got almost 20mpg on a recent power
> tour. It was a big surprise to him.

I show three Erson lobes:

 HIFLOW IM    242   286   .340  0.015 0.544
 HIFLOW IIM   246   296   .340  0.015 0.544
 HIFLOW IIIM  254   306   .340  0.015 0.544

I wonder if they have an updated lobe?  When you get the cam,
please post the cam card and valve spring info.  Did Woody
recommend helicoiling the cylinder heads where the rocker stands
bolt down?  What sort of oil do you plan to use?

Dan Jones

[NixVegaGT]

It's being worked out now and I will post every detail when I get it. It will be about a week or so. I already sent off a payment. BTW his spring sets are about $65. CHEAP!! The whole thing was a lot less expensive than I expected. I'll post an itemized list of the = cost details as they come through too. It sounded like around $250-$280 for a custom ground profile!

I will have to get the proper lifters from TA and that's not cheap. He thought it was around $230ish for a set. I actually did already have the heads helicoiled. It was SOP for my shop I guess. I didn't know it added strength to the perches. Interesting. I also have the D&D rocker shaft end supports. That should help me get through the effective RPM range he runs. His said his experience with this cam was it produced power to about mid 6k range. He figured 6800 was a good redline for the setup.

I'm pretty excited. I can't thank you enough for pointing me in his direction. It was really great talking to another motorhead that builds my engine too. It just doesn't happen very often. Good times. I can't wait for the engine dyno!

[BlownMGB-V8]

Some pretty interesting info, though I won't pretend to follow all the details. Should be a real strong motor, and that 6800 redline is bound to spoil ya.

If you guys are about through with Nick's combo I've got another one for you to consider, which will probably need a custom cam, but I'm not deep enough into it to figure out what the best setup would be. If you'd like to take a shot at it, here's the specs:

340 short block .030 over with stock high compression cast pistons
'64 300 heads with stock valves, about 10:1 compression
Eaton M-112 blower, intercooler, and port injection, boost probably around 8 psi, maybe a little more.
Equal length headers with 1-1/2" x 32" primaries and 2-3/8" collectors dumping into glass packs
6 grand redline based on the pistons. The valve springs can handle about anything I want to throw at them, about a 90 lb seat pressure and real good open pressure, they were good for an easy 7 grand in a 215.
This is supposed to be an economy motor for good gas mileage, and I'd like to see how far I can take that and still get something like 300+ hp out of it.

Obviously the blower throws a curve in things, since the intake side will easily flow enough under boost to produce the desired output even with a stock cam profile, but the exhaust side could use a little help as the exhaust valves are arguably a little undersized to begin with.

What do you guys think, want to kick this combo around a bit?

Jim

[hoffbug]

FYI
I was talking to the Crane Rep at the NHRA Lucas oil nationals and  he said they can no longer get cores for the Buick 215, 300, 340 but could do roller cams..

There are only really a few suppliers of cores.. does this mean that other manufacturers will soon be using up what they have on hand?  Or is the Crane rep full of hooey?

[NixVegaGT]

I wonder if they are just loosing the "215,300,340" listing. Maybe the just say Rover now??

[Dan Jones]

> Obviously the blower throws a curve in things, since the intake side will
> easily flow enough under boost to produce the desired output even with a
> stock cam profile, but the exhaust side could use a little help as the
> exhaust valves are arguably a little undersized to begin with.

Yes.  The old B&M blower catalog had a note when running their blower
on stock Ford Windsor heads that the blower could overheat due to the
restrictive exhaust and the Windsor has larger valves than the Buick 300.

> What do you guys think, want to kick this combo around a bit?

I don't have much experience with blower cams but typically they
run less overlap via wider lobe centers so you don't blow the
compression out the exhaust before it closes.  A typical Ford 5.0L
blower cam has 112 lobe centers with longer exhaust duration.
Some run the stock 5.0L cam which has 116 lobe centers (single
pattern with 204 degrees duration and 0.444" lift w/1.6 rockers)
and Crower's 351C blower cam is 114.  Anderson Ford Motorport has
a series of blower cams for the 5.0L Ford and the mildest specs out
at 218/226 degrees @ 0.050", 112 LSA, 0.542"/0.542" (this is a
hydraulic roller cam).  Closest off-the-shelf Buick cam would be
on of the Crowers, either the 50232 or 50233:

 50232 276HDP 276/281  214/218 .488/.490  112  
 50233 280HDP 280/286  220/226 .488/.501  112  

If you're interested, I've got both of those cams (new) here that
I'd sell.  Looking at the Erson lobes, the closest match to the
AFM blower cam would be a Hiflow AH intake lobe with a Highflow IH
exhaust lobe (220/228, 0.504"/0.504") on 112 centers.  If fuel
economy is a concern, maybe 114 lobe centers or even an RV15H intake
lobe:

 RV10H       208  280  0.280  0.448
 RV15H       214  288  0.288  0.461
 TQ20H       214  292  0.299  0.478
 TQ30H       226  310  0.310  0.496

 Hiflow AH   220  284  0.315  0.504
 Hiflow IH   228  296  0.315  0.504
 Hiflow IIH  235  306  0.315  0.504
 Hiflow IIIH 240  316  0.315  0.504

You might want to run this by Woody at the Wedge Shop (he works with
Steve Tanzi at Erson on the custom grinds).

> I was talking to the Crane Rep at the NHRA Lucas oil nationals and
> he said they can no longer get cores for the Buick 215, 300, 340 but
> could do roller cams..

Were they talking about hydraulic or solid roller cams?

> There are only really a few suppliers of cores.. does this mean that
> other manufacturers will soon be using up what they have on hand?

That would be bad.

> I wonder if they are just loosing the "215,300,340" listing. Maybe
> the just say Rover now??

Crane no longer lists the cams in their catalog.

Dan Jones

[hoffbug]

Dan.. he didnt specify what type of roller cams... Im assuming they would be custom billet but im not sure if there is a roller cam core or not.

[NixVegaGT]

I've not officially got a spare Crower 50232 if anybody is interested.

[Wotland]

Hello, here some selection of cams aviaible for Rover V8 in Europe:

Make   Number   Timing   Period   Valve lift   Lifters   Class   Comments
Oselli   RV8255   22/62/62/22   264°   .421"   Hyd .   Mild Road   Extra low and mid end power. Good for towing/load carrying.
Oselli   RV8271   28/64/64/28   272°   .439"   Hyd .   Road   Improves mid and top end power. Good flexibility.
Oselli   RV8214   31/73/80/34   284/294°   .469 "/.494"   Hyd.   Road   Good all round improvement.
Oselli   RV8286   44/72/72/44   296°   .439"   Hyd .   Road   Excellent road cam. Ideal for fuel injected engines.
Oselli   RV8480   36/76/76/36   292°   .480"   Hyd .   Fast Road   Extra mid and top end power. Ultimate for auto-transmission.
Oselli   RV8502   37/77/77/37   294°   .495 "   Hyd .   Road/Rally   Slightly lumpy tickover. Good power 2000 rpm upwards.
Oselli   RV8224   36/78/85/39   294/304°   .494"/.520"   Hyd.   Road/Rally   Extended top end power with up to 7000rpm
Oselli   RV84   35/71/71/35   286°   .516"   Hyd.   Rally   Good all round competition cam. Power band 2500-7000 rpm
Oselli   RV8481   42/82/82/42   304°   .496 "   Hyd.   Rally   Poor low end tractability. Power band 3000-7000 rpm
Oselli   RV8234   38/80/87/41   298/308°   .520"/.542"   Hyd.   Rally   Poor idle and low end but excellent power over 3500 rpm
Oselli   RV8500   46/82/82/46   308°   .542"   Hyd .   Race   Ultimate hyd. camshaft. Power band4000-7000 rpm
Oselli   RV8900   42/78/78/42   300°   .500"   Solid   Rally   Poor tickover. Excellent mid and top range power.
Oselli   RV8100   47/83/83/47   310°   .530"   Solid   Race   Maximum power for full race spec, engine.High rpm.
Kent   H180   28/64/64/28   272°   .439"   Hyd.   Mild Road   Good for automaticsPower band 1000-4500 rpm
Kent   H200   20/64/69/25   264°   .435 "/.460"   Hyd   Mild Road   For pre-SD1. Also good for automatics.
Kent   H214   31/73/80/34   284°   .469 "/.494"   Hyd.   Fast Road   Very flexible. Power from 1500-5000 rpm.Good road camshaft.
Kent   H224   36/78/85/39   294°   .494"/.520"   Hyd.   Road Rally   Slight loss of flexibility. Power comes in 2000-5500 rpm.
Kent   H234   38/80/87/41   298°   .520" /.542"   Hyd.   Rally   Poor low end, but improves mid and top end power.
Kent   GPA   44/76/76/44   300°   .390"   Hyd.   Rally   Same valve lift as standard engine (.390")
Kent   M238   42/78/78/42   300°   .512"   Solid   Rally   Higher rpm use. Power band from 2750-7000rpm.
Kent   M248   48/82/84/46   310°   .533"   Solid   Rally/Race   High rpm camshaft. Power band from 3500-8250rpm
Kent   M256   42/70/83/39   310°   .546"/.564"   Solid   Race   Ultimate race cam. Full race engine only. Power 4000-8250 rpm
Piper    HR270   22/62/64/28   264°/272°   .421"/.439"   Hyd.   Road   Flexible with good mid and top end improvement.
Piper    HR270/2   28/64/64/28   272°   .440"   Hyd .   Fast Road   Mk1 1 of above cam.
Piper    HR285   44/72/72/44   296°   .439"   Hyd.   Fast Road   Ultimate road cam. Tractable but slightly lumpy tickover.
Piper    HR300   36/68/68/36   284°   .440"   Solid   Competition   Accent on mid-range power. Power band 3000-7000 rpm.
Piper    HR320   52/84/84/52   316°   .471"   Solid   Race   Mid and top end power. Excellent circuit race cam.
Crane   H-194   10/54/59/15   244/254°   .400 "/.430"   Hyd.   Road   Economy cam only. Not to be used with comp. ratio over 8.75:1
Crane   H-204   15/59/65/21   254/266°   .430"/.456"   Hyd.   Mild Road   Improvement over standard cam. Can be straight swap.
Crane   H-216   21/65/71/27   266/278°   .456 "/.480"   Hyd.   Road   Excellent all rounder. Good power increase across rev. range.
Crane   H-224   36/78/85/39   294/304°   .494"/.520"   Hyd.   Fast Road   Slightly lumpy idle. Good for lighter vehicles eg. sports cars.
Crane   H-234   38/80/877/41   298/308°   .520"/.542"   Hyd.   Road/Comp.   Ultimate hyd. cam but compromise in road car.
Crane   F-228   38/72/74/36   290°   .491 "   Solid   Road   Particularly suitable for turbo or supercharging.
Crane   F-238   42/78/78/42   300°   .512"   Solid   Road/Comp.   Wide power band. Does not need high rpm.
Crane   F-248   48/82/84/46   310°   .533"   Solid   Rally   Wide power band. Works well with Holley 4-barrel carb.
Crane   F-256   42/70/83/39   292/302°   .546"/.564 "   Solid   Competition   Good mid and top end power.
Crane   F-266   47/75/88/44   302/312°   .564"/.584"   Solid   Competition   Out and out power. Engine must be capable of high rpm.
Crane   F-276   52/80/93/49   312/322°   ,584"/.602"   Solid   Competition   Radical race engines only. The ultimate.
JE Motors   JE101   20/65/25/20   265/225°   .430"   Hyd.   Road   
JE Motors   JE102   43/79/79/43   302°   .500"   Hyd.   Fast Road   Good power from 3000-6500 rpm. Peak torque 5000 rpm
Holbay   111R   39/73/73/39   292°   .429"   Hyd.   Fast Road   The Tornado
Holbay   125LHC   40/84/89/45   304/314°   .520"/.541"   Hyd.   Competition   Designed for maximum performance within rpm limits of hyd. lifters.
Holbay   K3A   58/88/74/50   326/304°   .432"   Solid   Competition   High torque design.
Holbay   751R   63/95/95/63   338°   .451 "   Solid   Competition   Maximum bhp at higher rpm.
Holbay   Standard   30/75/68/37   285°   .390"/.385"   Hyd.   Production   3. 5-litre (SD1)
Rover   Standard   32/73/70/35   285°   .390"   Hyd.   Production   3.9-litre (designation ETC 8686)
Rover   Standard   28/77/66/39   285°   .390"   Hyd.   Production   4.0-litre (designation ERR 3720)
Rover   Standard   14/70/64/20   264°   .416"   Hyd.   Production   4.6-litre (designation ERR 5250)

[NixVegaGT]

On Jim's cam: I was thinking bigger lift was better for forced induction. It sounds like thats what the Ford likes. Does rod ratio change duration? I would think that would only effect lift.

I bet longer rod ratios probably help too because of faster piston speed at BDC. That's got nothing to do with cams though.

WHOA, Dimitri. Thanks man. I guess I sat on my post for an hour. I didn't see it before now. (edit)

Actually this brings up a good point. How do you read the "Timing" numbers?

[BlownMGB-V8]

Looks like I may be trying to hit a moving target here. May have a deal on some Carrillo rods and Venolia pistons and obviously if that happens redline is going to go up, probably to the 6500-7000 range. But I'd like to keep the valve lift under .500 if it's feasible, and as mentioned shoot for max economy at the same time. Those are some pretty conflicting demands right there and I don't think it'd be possible without the blower. But I do love an engine that will wind up so why not go for it? I'm thinking wide lobe centers, minimum overlap, and near stock lift and duration on the intake, say around .400 on the lift, and then max out the lift and duration on the exhaust. I'll have to see what clearance my exhaust valves have at the seals and I'd prefer not to have to notch the pistons.

I have little doubt the end result will be a custom grind but I'm not concerned about that, I just want to get in the ballpark with the specs before I talk to the cam grinders. Wonder if Racer Brown is still around?

Jim

[Wotland]

Hello Nick, sorry was away.

Cam figures : BTDC/ABDC/BBDC/ATDC
Last figure give you the duration. Two figures when In/Ex duration is different.

LCA (lobe centre angle) : (duration/2) - valve opening point for the inlet or closing point for the exhaust
LSA (lobe separation angle) : (inlet LCA + exhaust LCA)/2

If I can give you an advice contact Rob at V8Developments in UK. This is the man for stroked Rover V8. He created an 5.5 with custom 3.7'' stroker crank and 3.8'' bore http://www.v8developments.co.uk/

[NixVegaGT]

WOW that's a lot more specific information. I like that method WAY better. Why don't we do it? I mean, you can get a card from Crower website, which is great, but most don't have that information readily available. I couldn't find anything specific like that about Isky. Is that because they want to keep it a secret?

I love it when the only information is: Street-strip or Race cam. WOW that's helpful. OK... I'm starting to sound like a crotchity beeotch.

My point is: Thanks Dimitri.

[NixVegaGT]

OK I got my cam specs from Woody at the Wedge Shop. It makes a lot more sense now:

LCA: 108º
Overlap: 74º
Timing: 35/71/75/39

Clearance Hot: 0.023

Lift: .544/.544

Adv Duration: 286/294


Specs @ 0.050:

Overlap: 38
Timing: 17/53/21/57

Duration: 250/253

It's a solid lifter cam. Custom ground to get the LCA. What Woody was saying to me over the phone is it's a 340 cam not 314 like I thought I heard. At the time I thought he was either talking about the lobe lift or the adv. duration. It's actually the lobe lift. It's got some pretty wicked lift. Hopefully I will clearance OK. 286/294 makes a lot more sense to me. We'll see how it all assembles.

Thanks again for the help guys.

[Wotland]

Hello Nick,
I found back an very good article from Rob about cams in Rover V8 :

I will come to cams and what I think are good and bad in a bit, firstly what are you trying to achieve is to get the engine to fill its total cylinder capacity throughout its rev range, easy said impossible to do unfortunately,
The first place to start is the cylinder heads, a real good flowing pair of cylinder heads means you don't need such a viscous cam to make decent horsepower!, unfortunately this is what lets the rover engine down big time, even in the 500 TVR heads the valves are just no where near big enough to flow the air that is required, so we are left with trying to make some decent bhp and drivability with a cam.
LIFT,
basically as much lift as you can get the better your engine will perform through the whole rev range regardless of cc's, the rover head flows it most cfm when the valve is something like 700 thou from is seat, the reality here is no rover cam lifts that far because it just cant, 600 is about its max, lift is related to duration, you cant have lots of lift with little duration as the valve will be being opened so quick that the cam follower will just dig into the side of the cam profile and break, so with a 600 though lift you are going to need 320 deg of duration, what you now have is a full circuit race cam that will only make power from 5000 rpm upwards!
DURATION
Duration is the time the valve is lifted of its seat, to little you will have no power too much the car will drive like a pig, However duration, LCA "lobe center angle, and overlap are all related, its not so much the duration that kills drivability its the overlap, just 10 deg can make or break the engine!, so duration make bhp lift makes both, as I said in the other post I am only going into road engines!.
The LCA is the angle between full lift on the inlet and full lift on the exhaust lobe, by making this wider you can tame the cam for the same given duration, however what will happen is the cam with the wider LCA will idle better drive smoother make more bhp and have a wider torque curve, the cam with the smaller LCA will only have a benefit in the mid range, around peak torque. so in my honest opinion for a road cam i like to go for around 285-290 deg of duration with a wide LCA around 114, this to make a good road sports cam, you can drive it down the shops with no hunting and use it on a track day as well, the same cam on a 108 LCA will make it more peaky in the mid range, but you will have to keep changing gears in slow traffic and it will drop of the cam quicker too, peak power will be around the same but where the 114 will still be making good power at say 6500 rpm the 108 will be dead and buried and need a gear change, a race car is totally different i would spec a a cam to work in the rev range I wanted and make the most of that rev range.
mc1 good idle, excellent drive ability, reasonable bhp.
mc2 poor ish idle, poor ish drivability good mid range, good bhp.
h404 very poor idle, crap drivability, good mid range, excellent bhp
stealth very good idle, very good drive ability, ok ish mid range, good bhp.
Piper 270 ok idle good mid range crap bhp
Piper 285 crap idle, poor drive ability, very good mid range, ok bhp, falls off the cam very quickly
Piper 300 crap idle crap drive ok mid range good bhp
Kent 200 very good idle good drive poor every where else
218 good idle good drive good mid range poor bhp
214 ok idle ok drive ok mid range ok bhp
224 poor idle, poor drive, good mid range, good bhp
234 crap idle crap drive, good mid range, excellent bhp,
These are all based on the fact that you will be running standard management systems and a plenum, there are of course many more cams out there but these are the general ones you will buy.
So to sum things up a bit, if you want a good low down nice driving torque cam go for a cam with a max of around 270 deg duration and a LCA of around 112 deg.
if you aren't bothered with idle qualities and want a good mid range cam go for one with a low LCA and around 280 deg of duration.
if you want a track day cam or fast road cam go for around 300 deg and around 110 lca
if you want a good all rounder go for around 285 deg and wide 114 LCA, both Kent and Piper will make cams to what you want within reason so give them a call, the Piper 285 for instance, loses nearly 25 bhp over the 404 at the top end, this on a controlled dyno not a rolling road, but it gains around 10 ftlb at around 200-3000 rpm, but if you asked Piper to grind it on an LCA of say 110 you would only be losing around 10 bhp at peak, 300 but gaining around 20 ftlb at 2000-3000.
Also please note cams cannot be judged against other cams on rolling roads, especially different rolling roads, there are too many variants, all the way from the air filter to the oil in your gearbox and diff!!!!!
Throttle bodies against plenums and cams!!
What I briefly said earlier with overlap cams, this will murder an engine running a plenum, where as on throttle bodies it tends to smooth thigs out a bit, take a single plenum all 8 cylinders draw from this one opening, not a problem there in fact it is good as each cylinder can draw as much air as it wants with no restrictions as far as air flow is concerned. The BIG DOWNSIDE TO A PLENUM, on the overlap period part of the cam, this is where both exhaust and inlet valve are open at the same time, i.e. at the end of the exhaust stroke where the piston is forcing the burnt gas out the exhaust port the inlet valve opens before the exhaust is shut, instead of the unwanted rubbish going out the exhaust it is sent back up past the inlet valve and into the plenum, this is more aggravated by the fact that the next cylinder is sucking hard and will suck the waste out of the disposing cylinder into the good one, the problem here becomes that it is not fresh and lacks oxygen, so instead of the new cylinder getting a good charge of fresh air and fuel, it has 20 or 30% of nothing that cant be ignited, hence poor combustion poor idle and low power, This is only at low ish rpm, at high rpm you have the advantage that the exhaust manifolds are "should" be scavenging the fresh inlet charge into the cylinder, if you have the money to go to throttle bodies then this is where the biggest gain is going to come in the low to mid range, on the overlap period each cylinder can only contaminate its own cylinder, and part of this will be lost to the atmosphere anyway, so generally lets say at below 3000 rpm a plenum is giving a cylinder 70% of fresh charge to be ignited a set of throttle bodies will be giving 90% at the equivalent rpm all this = more ftlb of torque, just be careful you don't go too small on the throttle bodies or this will hurt the top end breathing, you have gone from a 72 mm plenum and as I said each cylinder will see 72 mm down to what ever size your throttle body is.

Hope it helps you.