What Cam for my 3.5?

tetlow · Post by **tetlow** » Sun Jul 01, 2007 9:23 pm

I am swapping blocks soon, I hope, and I thought I would replace the std cam with something better.
I still want good idle but more power.
The cam I have is in good condition, am I wasting money or would a new cam give me gain with no pain! Also the followers have done under 2000 miles as per the cam, should I replace the followers too? I have the 3.5 with 9.75:1 pistons, Webber 500, tubular twin exhausts.
Regards

Dave

Post by **katanaman** » Mon Jul 02, 2007 9:45 am

WHat cam depends what you use the car for and what the car is, sorry cant remember what you have. More info will help with suggestions.

As to followers yes you have to replace the followers with a new cam.

ChrisJC · Post by **ChrisJC** » Mon Jul 02, 2007 12:48 pm

I would say that assuming it's for an MGB then you'd be fine to get a more powerful cam. If it were something big and heavy like a Range Rover then it would be more appropriate to get a torquey cam rather an a high BHP cam.

But I can't imagine that it takes much to get an MGB moving, so sacrificing a little bottom end torque for top end BHP would be OK.

Chris.

Wotland · Post by **Wotland** » Mon Jul 02, 2007 4:20 pm

Hello,

Just an Excel File to show you some cams with their own characteristics :

http://patoula.chez-alice.fr/land_rover/aac_rover.xls

Cheer

tetlow · Post by **tetlow** » Mon Jul 02, 2007 5:57 pm

Thanks chaps.
I have a MGB roadster and would like to keep the smooth tickover, but use a better designed cam than the std Rover one.
I am running out of dosh so I am unable to pay big bucks for one.
Can you get more power and enonomy out of a newer designed cam than the old ones?
Regards
Dave

Nick Moore · Post by **Nick Moore** » Wed Jul 04, 2007 12:21 am

I'm building a 3.5 with pretty much the same specs as yours - Weber 500, 9.75:1 etc. I chose a Crower 50232 cam, as it's fairly cheap, popular, is supposed to retain a fair idle, reasonable torque low down and doesn't require valve cut-outs in the pistons. The next Crower grind, 50233, for example, does need cutouts.

I haven't any first-hand experience of the 50232, so will have to wait and see how it drives. I have driven a TR8 with four SUs and a Real Steel Typhoon camshaft, and if the Crower is that good I'll be a happy chappy!

tetlow · Post by **tetlow** » Thu Jul 05, 2007 8:06 pm

Thanks Nick
Dave

mgbv8 · Post by **mgbv8** » Thu Jul 05, 2007 8:21 pm

Dave
My present 3500 runs a Typhoon cam with rhoades lifters. Gives a smooth idle and the lifters bring the cam on at 3700 ish rpm as seen on the dyno plot.

I get a smooth torque curve up to 3500 rpm, then at 3700 rpm the curve jumps up some more.

I run a 8:1 CR engine for road use and its fairly sweet even with the auto box. But when I stick the gas on, she turns into a 12 second monster MGB.

The new engine I'm building has a blower cam. Pretty much the same lift as a the Typhoon, but the lobe sep is better suited for more nitrous.

Pop along to Santapod on Saturday and you will see how my old low comp 3500 performs on the strip. I will be at the MG Drsg Racing Club stand in the pits. Only 12 quid to get in for a good days viewing of classic car racing on the 1/4 mile.