Thread: Good deal on V8 camshafts but help me choose one

DW268 Viper 'Stump Puller' Hydraulic Camshaft for 3.9 and above Price:£127.37
Installed in a 4.0 litre engine, this cam gave 267 ft lbs of torque, at 4000rpm, and 260 bhpat 5500rpm. Installed in a 4.3 'stroker' engine, we obtained 297 ft

In Tuning Rover V8 Engines by David Hardcastle the standard specs of a 3.5 V8 as fitted to a range rover were

135BHP at 4750RPM and 205Ft Lb at 3000RPM.
The MGB V8 was ismilar at 137BHP at 5000RPM and 193 Ft Lb at 2900RPM.

I would suggest that the "Stump Puller" is not really a stump puller at all and will give less low rev torque than a standard cam.

Seeing the v8 sits at about 2000-2500 mostly on the highway, I repeat my recommendation is a standard 3.5 cam.
Regard sPhilip A

Real Steel also do the newer Cyclone cam for the 3.9.

But I suggest the Crower 50229 - for Buick 215/Rover V8.
Claimed to be worth 20 BHP over OE camshaft on a 3.5, ideal for most applications where smooth power delivery is required and strong low end torque. Gives good tickover and also suits automatic trans installations.

Idle - 850rpm - power from 1500 - 4500rpm
258° - 430 lift.

50229 258HDP 258/260 196/202 .430/.446 112 1500 to 4000/ redline 5500.

Available from D&D in the US.
D&D Fabrications: Engineering & Fabrication Services

Originally Posted by frantic

Why dont you try and fix the restrictive air issue first? This may give you more than enough power if you open up the air flow. Also if you see the air flow as a issue currently, it will still be an issue regardless of what cam is fitted.

My understanding (such as it is) of air flow is that restrictions only become a signifnicant issue in the higher rev ranges. Because I dont really want/need to rev it over 4000 rpm, it doesnt concern me greatly.

Originally Posted by Traco

Real Steel also do the newer Cyclone cam for the 3.9.

But I suggest the Crower 50229 - for Buick 215/Rover V8.
Claimed to be worth 20 BHP over OE camshaft on a 3.5, ideal for most applications where smooth power delivery is required and strong low end torque. Gives good tickover and also suits automatic trans installations.

Idle - 850rpm - power from 1500 - 4500rpm
258° - 430 lift.

50229 258HDP 258/260 196/202 .430/.446 112 1500 to 4000/ redline 5500.

Available from D&D in the US.
D&D Fabrications: Engineering & Fabrication Services

I know this is still relatively a mild cam but according to the Crane cams website the stock cam makes power from 800 -3500 rpm. I dont doubt that the above cam makes more overall hp but it would have to shift the torque peak upwards by 700-1000 rpm. For maximum driveability I want as much off-idle torque as possible and I dont care if its all over by 3500-4000 rpm.

Originally Posted by PhilipA

In Tuning Rover V8 Engines by David Hardcastle the standard specs of a 3.5 V8 as fitted to a range rover were

135BHP at 4750RPM and 205Ft Lb at 3000RPM.
The MGB V8 was ismilar at 137BHP at 5000RPM and 193 Ft Lb at 2900RPM.

I would suggest that the "Stump Puller" is not really a stump puller at all and will give less low rev torque than a standard cam.

Seeing the v8 sits at about 2000-2500 mostly on the highway, I repeat my recommendation is a standard 3.5 cam.
Regard sPhilip A

I agree with these observations on the so called 'stump puller' cam.

Found some specs on the early low comp carb cam in the factory workshop manual - it has less duration that the high comp carb cam and the efi cam. From what I can gather, less duration equates to a torque peak at lower rpm, other things being equal.

Originally Posted by mark2

I agree with these observations on the so called 'stump puller' cam.

Found some specs on the early low comp carb cam in the factory workshop manual - it has less duration that the high comp carb cam and the efi cam. From what I can gather, less duration equates to a torque peak at lower rpm, other things being equal.

You can't really compare carb and efi (independant runner) cam specs - very different operating princibles.

How high is your compression ratio? if its stupid high, you may find a torquey cam will could cause too much pinging.

What cam is in there now? if its a 3.5 carb cam and you replace it with a 3.5 carb cam, well.... you're not really doing anything other than wasting time and money

Originally Posted by Hardchina

You can't really compare carb and efi (independant runner) cam specs - very different operating princibles.

How high is your compression ratio? if its stupid high, you may find a torquey cam will could cause too much pinging.

What cam is in there now? if its a 3.5 carb cam and you replace it with a 3.5 carb cam, well.... you're not really doing anything other than wasting time and money

I have no idea what the cr is but I wouldnt say it is 'stupid high' on the basis that it doesnt ping on petrol, with a reasonable advance setting for lpg. I can only hope the oversize pistons which were fitted made allowance for the stroke increase. It shouldnt ping on lpg in any case which is most of my usage. Having said that, a few posters have suggested lpg doesnt really care much about cam profiles so maybe it doesnt matter what cam I choose.
The current cam has been in there a long time and the tappets are noisy. The lobes are likely worn and the timing chain is probably stretched. So even if by chance I put the same cam back in it should run better and more quietly.

Thought about going solid?