7 replies to this topic

[ollydc5]

I've recently got my hands on a 1275cc engine ready for a 1293cc build. Just looking into cams etc and have read that the mg 1300 cam is a great oem cam to use.

how different is this cam compared to what I've brought ?

I've got a rough spec I'm working towards, hope this sounds worth it. The engine I've brought had slight issues

1275 bored out to 1293
Pistons
Rods
Stage 2 head
1 1/4 su's
Rc40 free flow
1.5:1 rockers
Aldon electronic dizzy


Unsure on what cam to use, have got £3k to spend on the engine and gearbox. Have got the engine, su's and exhaust

[nicklouse]

I've recently got my hands on a 1275cc engine ready for a 1293cc build. Just looking into cams etc and have read that the mg 1300 cam is a great oem cam to use.
how different is this cam compared to what I've brought ?
I've got a rough spec I'm working towards, hope this sounds worth it. The engine I've brought had slight issues
1275 bored out to 1293
Pistons
Rods
Stage 2 head
1 1/4 su's
Rc40 free flow
1.5:1 rockers
Aldon electronic dizzy
Unsure on what cam to use, have got £3k to spend on the engine and gearbox. Have got the engine, su's and exhaust

What are you asking you don't list a cam to compare it to?

And I would not bother with twin SUs.

[ollydc5]

Sorry about that, must admit I'm not 100% sure what the 1275 engines standard cam profile is :-( all Ive been told is that the MG metro standard Cam is good to use and that's what I should buy. I'm getting so many mixed answers from friends which is a bit confusing.

having to learn the hard way sorry

[Mini Manannán]

I've recently got my hands on a 1275cc engine ready for a 1293cc build. Just looking into cams etc and have read that the mg 1300 cam is a great oem cam to use.

how different is this cam compared to what I've brought ?

 

 

What cam have you bought?  You don't say.

 

What do you want the car for?  Do you want a car that is pleasant to drive on the road with bags of torque that lets you get away with minimum throttle?  Or do you want a lumpy idle that needs revs to get away?  Or do you want full-on race?  Each to their own but I know how I'd want my engine set up and it isn't the second option.  Remember the old saying: "torque wins races"

[jaydee]

What cams are you talking about?

The MG 1300 cam is basically a 510

The more famous MG metro is a mix of a 948 inlets and 731 exhaust

Two totally different cams

[ollydc5]

Im not sure what Cam I have, it's still in the block at the moment but should be out soon. Are there any markings on it to help determine what I have already ?

As for the build I don't mind if it's a little lumpy, definately don't want anything race spec Just a nice useable torque car. Would probably help if I knew what cams were from what engines, is there any specific tables showing this ?

[carbon]

If you're building a 1293 fast road spec car then the MG Metro or Kent MD266 cams are good starting point. If you want a 'lumpier' cam then use the 1.5 lift rockers with these shorter duration cams. Or try out the recently released 1.4 rockers from Keith Calver.

 

If you don't use it in traffic too much then maybe go for the Kent MD275 or the RE130.

 

I've used the MD266 in a couple of fast road motors, and it works well. Needs CR of about 10:1 and I've used the larger inlet valve and standard exhaust valve sizes in a slightly ported 940 head.

 

With the dizzy getting the correct advance curve is critical for performance. And this is not trivial for a good fast road engine.

 

Twin SUs can work, but do take quite a bit of effort to get the best out of.

 

Unless you are buying a lot of shiny bits or paying someone else to build the motor this should not cost more than £2K. You should also consider what gearbox and final drive you will be using.

[carbon]

And I would recommend buying a copy of David Vizard's 'Tuning the A-Series Engine'

 

First published 30 years ago, but the basics have really not changed.

 

This book has pretty much all of the information you need about cams, blocks, pistons, ignition systems and carbs all contained between its covers.