15 replies to this topic

[mik]

Hi Guys (and girls)

My first post to the mini forum, but been here for years. If i get something wrong, dont be shy, let me know.

I’m Needing some advice on the mad world of Cam shafts.

I’m currently running a very old 649 cam in 1380 race engine and i want to change it for two reasons. Firstly, and Predictably, more hp, and secondly, I want to fit a new competition oil pump and the 649 wont drive it.

Here’s the spec. I run this engine in a hillclimb mini on 8 inch avon slicks, carbon front end, rear sub frame replaced with beam, lightened everything etc., so speed is the only thing that matters here.

I’m offset boring a new a+ block for 73.5 omega pistons. Carb is a 48 dellorto twin choke. Steel crank, lightened steel flywheel, comp clutch and straight cut jack knight box. All the bits. The head is a 5 port from Brian Slark with alot of work done to it, big valves and hardened standard a+ rockers.

This engine is limited to 8500 rpm, which it does without problem. I’ve been studying David Vizard’s bible (3rd ed) and I’ve read a bit about scatter pattern cams but my brain is melting with LCA, CR, overlap, and all the maths.

Could you recommend a cam profile that would suit this engine, and help me frighten some of the guys in my class with 16v’s.

any advice greatly appreciated and thanks in advance for your time guys.

Cheers

[Wil_h]

It's easy to keep up with the 16v boys, you just need a turbo!!

There is an interesting thread on TM at the moment about cams click the request is not for a hillclimber, but some interesting thoughts. Look at what Paul Wiggington says, I can't think of a faster 1380 mini, not sure what cam he has though, you could ask him, he visits here sometimes.

Edited by Wil_h, 28 April 2010 - 02:28 PM.

[miniobsessed]

Maybe something around the spec of a Kent MD315 will get you where you want to be... But this is some serious duration with quoted power band from 4500 - 9000rpm.

I'd also recommend talking with a guy here in Australia... Graham Russell. He has done extensive R&D on mini camshafts... GR's Website

Keep us all updated on your progress

[Ivor Badger]

8500 seems a lot for a 649 on a 1300. What rev counter are you using.

As for cam, although I am told I am wrong, a super sprint would be my choice. Unfortuately, probably only regrinds are available now and that might cause them not to work.

[CobraV8]

I have a SuperSprint Cam in my 970 motor, and while they do scream along, apparently the 649 is generally a better cam, especially where torque is required on a hillclimb car.

I personally would be looking further into a scatter pattern cam, this will give you a better spread of power.

[Ivor Badger]

I have a SuperSprint Cam in my 970 motor, and while they do scream along, apparently the 649 is generally a better cam, especially where torque is required on a hillclimb car.

I personally would be looking further into a scatter pattern cam, this will give you a better spread of power.

According to Longman, the super sprint will not work in the 970 engine.

[mini-man-dan]

Have you spoken to Brian or Neil? I'm sure they'll be able to give you some sound advice in English rather than mathematical lingo!

Edited by mini-man-dan, 28 April 2010 - 10:21 PM.

[CobraV8]

I have a SuperSprint Cam in my 970 motor, and while they do scream along, apparently the 649 is generally a better cam, especially where torque is required on a hillclimb car.

I personally would be looking further into a scatter pattern cam, this will give you a better spread of power.

According to Longman, the super sprint will not work in the 970 engine.

Interesting - I had not seen that said before. It worked, but I reckon more power can be unleashed by others. Where did you read that from Longman?

[Ivor Badger]

I have a SuperSprint Cam in my 970 motor, and while they do scream along, apparently the 649 is generally a better cam, especially where torque is required on a hillclimb car.

I personally would be looking further into a scatter pattern cam, this will give you a better spread of power.

According to Longman, the super sprint will not work in the 970 engine.

Interesting - I had not seen that said before. It worked, but I reckon more power can be unleashed by others. Where did you read that from Longman?

didn't read it, he told me.

[CobraV8]

I have a SuperSprint Cam in my 970 motor, and while they do scream along, apparently the 649 is generally a better cam, especially where torque is required on a hillclimb car.

I personally would be looking further into a scatter pattern cam, this will give you a better spread of power.

According to Longman, the super sprint will not work in the 970 engine.

Interesting - I had not seen that said before. It worked, but I reckon more power can be unleashed by others. Where did you read that from Longman?

didn't read it, he told me.

What cam did he recommend for a full race 970?

[Ivor Badger]

What cam did he recommend for a full race 970?

He didn't, we were discussing cams for 1275s and while recommending a SS, he said they didn't work in 970s.

[mik]

Hi guys

I'm the guy started this great cam debate. just had an email from del at Kent cams, he reckons a 296 scatter pattern would suit my spec, up to 8000 rpm.

He didnt give a price but this is a pretty aggressive cam, no? anyone got experience with this one. From what i can determine, i really need 1.5 high lift roller rockers to get the best out of this type of cam. startin to get expensive now.

Thanks for all the info, it all helps.

[mik]

 hcl1.jpg   94.58K   11 downloads  hcl2.jpg   70.37K   10 downloads

tryin to upload shot or 2 of our hillclimb mini before start of last season. This is the one with the 649. we're well proud.

[CobraV8]

looks awesome, best of luck with the competition.

[liirge]

Hi guys

I'm the guy started this great cam debate. just had an email from del at Kent cams, he reckons a 296 scatter pattern would suit my spec, up to 8000 rpm.

He didnt give a price but this is a pretty aggressive cam, no? anyone got experience with this one. From what i can determine, i really need 1.5 high lift roller rockers to get the best out of this type of cam. startin to get expensive now.

Thanks for all the info, it all helps.

I believe Guessworks on here runs a 296, PM him and see what he says about it, if i remember correctly, he was a fan!