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MG MGB GT V8 Factory Originals Technical - Camshaft timing

Hi all,
A question about cam timing.
I have a timing chain set that has a 4 deg advance and retard keyway. Do I want to use either of these?
Some specs to knock around.
Rover 3.5
265 deg cam
9.75:1 pistons with felpro gaskets
3.9 heads
Buick 4V intake with a carter 400.
RV8 headers

Thanks,

Kelly


Kelly Combes

Kelly,
I'm at the same juncture here's what I think I know...Advancing 4 deg will shoft your power band down giving you more low end torque. Since these MG's are light will ungodly amount of torque anyway, not to mention the stock 3.9 rear; I had planned on running mine 4 deg retarded if anything. In the long run I think I decided to run it "stright up" and see how this worked, then either change the the timing/cam or both. This may not be of any help but maybe I atleast "primed" this thread for you.
I'm currently trying to use a Piper Rp4 (260 advertised) so far I'm not impressed and it's not even in the car yet. What cam do you have and where did you find it?

Good Luck,
Hal
Hal

Kelly,

Here's the link to that archieve I read (much the same question).

http://www2.mgcars.org.uk/cgi-bin/gen5?runprog=mgbbs&access=&mode=archiveth&subject=36&subjectar=36&thread=20001215173232324

If this doesn't work, search all words <piper camshaft> and it should be the first thread titled <Camshaft>

Hal
Hal

Wey Hey
Clicked on the link and up pops my name.
Ive been using the piper 270/2 for the last 3 yrs.
Its fairly mild. Think Ill change to a Viper Typhoon next.Dont ask me about cam timing, I just kept it standard as the book said.

Mark
Mark

Mark ,
It just goes to show you that if you stick around long enough you start seeing things over again!

Are you still running carbs or have you gone EFI? Where can I get more info on this Viper Typhoon cam?

Thanks,
Hal
Hal

Thanks for the input. The archive helped. I guess I'll stay with the straight up for now and see how it works.
Hal, I bought my cam off of ebay about two years ago. Just getting it in. It was for an olds 215.

Kelly
Kelly Combes

Hal
Im running the edelbrock 500cfm and offy manifold.
Ive seen the Typhoon cam advertised by a company called Real Steel here in the UK.

Mark
Mark

Unless you degree the cam, you have no way to know what you need to do.

Like Hal, I see no point in advancing a cam beyond the manufacturer's specs on such a light car with plenty of torque.
Carl

An old hot rod and racer trick is to do a cranking compression test on the engine with the cam at the different settings. Where the compression is highest is what the engine wants most.

Wayne
Wayne Pearson

Thanks for the tip Wayne.

Jim
Jim Blackwood

You could also run the figures through the DCR calculator that was posted recently posted here. Don't know if there'd be a problem, but with 9.75 CR it'd be nice to check in advance for any unforseen CR issues. You need the ICA of your cam to use it.

Kelly,
Which rods, jets, and springs are you using in your Carter 400? I got a rebuild kit for mine which included some of that stuff, but they are stock replacement parts and the carb was originally on a 340 Buick.
Glenn Kendall

Kelly,

My engine is a similar spec, I would advise you most strongly to retime the cam for max torque, I have never regretted it for a moment........

It pulls from 1000rpm in 5th

Top gear motorway acceleration is superb.

I never have to use revs, so fuel consumption is good, and the engine will hopefully last longer.

You can never have too much torque in my opinion ( and in the opiniion of Mr Shelby 'horsepower sells cars.. but torque wins races )

Last nights Top Gear programme had a sprint between a supercharged Jaguar and the hottest Holden, torque vs horsepower. The torquey Jaguar left the Holden standing, and yes, the Holden eventually caught up and crossed the line first, but how often do you get a situation in real life where you run the car through all the gears to flat out.,

I know which I would prefer at the traffic lights !

Mike


Michael barnfather

This thread was discussed between 01/12/2003 and 08/12/2003

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