20 replies to this topic

[TehMarchant]

Hi guys, So I bought this cam on ebay for £37 posted and I am planning a 1275 engine rebuild, The car is only for blasting around on the weekends and going to shows.

 

Has anyone got any information on these camshafts because I have read on kent cams that its a race cam but I have also read these work in 850s and is basically a 649.

 

I have also read that these should be spider drive but mine is slot drive.

 

Any of you older techys have an idea?

 

Cheers Ryan.

[nicklouse]

Can be slot drive as well.

And as you say all the info is on kents pages.

http://www.kentcams....shaft/530-Race/

Power 3000 to 7000 not much fun on the road. Will need a low final drive.

[RossKnight]

Minispares sell a slot drive kc530 - http://www.minispare...fts/kc530m.aspx

 

Specs - http://www.kentcams....shaft/530-Race/

[RossKnight]

Ah beaten to it.

 

I've used to daily a KC800 cam in a 1293 with stage 3 big valve head etc, didn't really drive bad at all, in fact, very docile. Couldn't feel it 'come on cam'

 

KC800 is 2500 - 7000, was running it with a 3.1 fd though.

[TehMarchant]

I plan on using my final drive from my old 998, not sure on the ratio but I will work it out when I come to stripping that gearbox down.

 

Cheers guys, gives me a little more confidence in the cam.

[RossKnight]

998 fd will most probably be 3.44

[RossKnight]

https://vid.me/Ln3I

 

This is mine with the KC800, you can't really hear a distinguishable powerband or 'on cam' noise. I think power at 3000-7000 would have been more fun actually.

Edited by RossKnight, 10 March 2016 - 07:43 PM.

[Dusky]

A 643 ish cam is the furthest I'd go. I've driven slalom with a 649, to use that on the road you must like changing clutches!

[Cooperman]

With that cam you will need a fully balanced engine, a 3.9:1 FDR and a SC CR gear set. You will also need a really well gas-flowed head with big valves.

It will be very poor to drive in any sort of traffic and expect to be using 7000 rpm to get best power.

It is known as 'over-camming'.

However, if you are going to build a race or hill-climb car it would be ideal. I wouldn't even use it in a tarmac rally car.

[TehMarchant]

With that cam you will need a fully balanced engine, a 3.9:1 FDR and a SC CR gear set. You will also need a really well gas-flowed head with big valves.
It will be very poor to drive in any sort of traffic and expect to be using 7000 rpm to get best power.
It is known as 'over-camming'.
However, if you are going to build a race or hill-climb car it would be ideal. I wouldn't even use it in a tarmac rally car.

My midge is only a weekend race about. I have my sccr gear set I will be dropping in. I will need to check what fd sets I have around. I am going to be compleatly rebuilding the engine this cam will be in and I will be balancing the crank and the flywheel, probably even go for a lightened one. Centre strap will also be installed.

[Cooperman]

I would recommend a 3.9 FDR with that cam
Give it a go. You can always whip the engine out and change the cam if is a bit too much.

[MRA]

It all depends on the other parts, with a usable rev range of 3000 to 7500 and a 285/281 duration it is still not much of a race cam, you will be fine with a slightly higher FD ratio up to about 3.44, a 3.9 is seen as a rubbish ratio for road use by lots of people who have tried it, on the road and you will very quickly tire of the excessive revs and extra noise, try driving around in 3rd gear to see what I mean.

 

Although a better cam would be the KENT MD286 as it pulls the power down by 1000 rpm at the lower end only

 

Don't forget these cams where designed to fit in smaller A series, so the bigger the displacement the less of a "race" feel you will get, you can up the cam and still get good results providing you don't want modern refinement, it will be all snorty and revvy and you'll love it, but if you fit a 3.9 FD ratio you will forever want to change it

 

What ever ratio final drive you fit, make sure you come back on here and tell us your thoughts.

[MRA]

Try this with a few combinations....

 

http://www.guess-wor.../Tech/ratio.htm

[Cooperman]

The 286 will give it's best power at 6400 rpm with peak torque arriving at c.5000 rpm.
I use a 286 in my 1310 'S'. Quite 'cammy' low down but very strong from 4500 rpm. It needs a really good head and carbs and a strong bottom end.

[MRA]

 

With that cam you will need a fully balanced engine, a 3.9:1 FDR and a SC CR gear set. You will also need a really well gas-flowed head with big valves.
It will be very poor to drive in any sort of traffic and expect to be using 7000 rpm to get best power.
It is known as 'over-camming'.
However, if you are going to build a race or hill-climb car it would be ideal. I wouldn't even use it in a tarmac rally car.

My midge is only a weekend race about. I have my sccr gear set I will be dropping in. I will need to check what fd sets I have around. I am going to be compleatly rebuilding the engine this cam will be in and I will be balancing the crank and the flywheel, probably even go for a lightened one. Centre strap will also be installed.

 

A much better option to strapping the centre main is to cross drill the crank....  the strap once fitted will need to be line bored to get the best from it, the two mating surfaces of the cap and strap should be surface ground to get a good fit.... cross drilling has saved more bearings from disastrous cavitation than a main strap has saved cranks that are only revving to 7000.