16 replies to this topic

[thatsclarke]

Help please!

 

I am in the market to upgrade my engine to make it quick, reliable and fuel efficient (i know im not asking for much)

I have an A+ 1275 metro rebored to 1293. The camshaft is the original metro cam. When i first got the car running it made 69bhp. That has now dropped to 64bhp in a year with minimal driving and is now becoming very juddery when i drive so I'm going to rebuild it.

Now,

What i need help with is deciding which cam to get and I have a few options:

MED RS - 264 duration with a power band from 1250-6500rpm

ACD RS -  Duration @ 0.016"  248 with power band from 1250rpm to 6000rpm,

Evolution001 - 264 Duartion  unknown power band

 

I was also planning to buy:

1.3 roller rockers or 1.28 modified A+ rockers

lightened flywheel

adjustable vernier duplex

double valve springs

have my 12g940 head ported and gas flowed with new valves and seats

 

Question is, which camshaft should i buy if i want a smooth idle, but when i put my foot down the power kicks in promptly and accelerates quickly through gears. And with this, what parts from my list of other upgrades should i pair with the suggested cam to have an overall strong, reliable, fun, efficient engine. 

The parts will all be put together properly and timing etc done as perfectly as possible.

Any other parts i should add to my list please comment!

 

thanks for the help

Edited by thatsclarke, 08 April 2020 - 04:35 PM.

[DeadSquare]

Supercharger.

[evoderby]

Programmable ignition + injection. When properly set up this makes even the wildest of cams behave like docile puppies and also works wonders on fuel economy.

[thatsclarke]

Programmable ignition + injection. When properly set up this makes even the wildest of cams behave like docile puppies and also works wonders on fuel economy.

like electronic ignition kit? like accuspark and set the ignition to X

[Zami]

I have similar mods to what you are considering so on the cam question I favor the Swiftune SW5-7. I have run a number for of different cams and the Swiftune is by far my favorite from idle all the way up to 6500. II would also highly recommend an electronic distributor as noted by thatsclark

[Stevie W]

+1 for the above.

 

I installed an SW5-7 in My 1293cc A+ engine, accurately timed in with a vernier cam gear and duplex chain. The engine runs a fast road Minispares head and twin 1.25" SU's. I also have an Aldon yellow A+ dizzy and electronic ignition installed.

 

The tickover is smooth (for an old engine design and carbs) and it pulls willingly from about 1500rpm right up 6000rpm and the acceleration seems to just keep coming.

 

Cheers, Steve.   

[thatsclarke]

+1 for the above.

 

I installed an SW5-7 in My 1293cc A+ engine, accurately timed in with a vernier cam gear and duplex chain. The engine runs a fast road Minispares head and twin 1.25" SU's. I also have an Aldon yellow A+ dizzy and electronic ignition installed.

 

The tickover is smooth (for an old engine design and carbs) and it pulls willingly from about 1500rpm right up 6000rpm and the acceleration seems to just keep coming.

 

Cheers, Steve.   

how do you know which aldon dizzy you need because theres alot of different ones, how did you know which one you need specifically for your engine? was it a 100AYV? did you need the vaccum advance? i didnt really want to buy a new dizzy, thats why i was thinking of getting the ACD RS or Evolution001 because they are £100 cheaper and i feel like the sw5-7 isnt getting an extra £100 worth of performance boost in comparison.

dont suppose you know how much bhp/torque youre getting in your 1293? 

i didnt really want to fork out for a new dizzy aswell

Edited by thatsclarke, 08 April 2020 - 08:19 PM.

[thatsclarke]

I have similar mods to what you are considering so on the cam question I favor the Swiftune SW5-7. I have run a number for of different cams and the Swiftune is by far my favorite from idle all the way up to 6500. II would also highly recommend an electronic distributor as noted by thatsclark

thanks for the response, which other cams have you used in the past? any of the 3 cams i have listed in the topic?

Edited by thatsclarke, 08 April 2020 - 08:21 PM.

[thatsclarke]

This features an RS cam with a 1330 bottom end but only a 33mm inlet valve, and uses twin hs4 carbs and 1.3roller tip rockers.

[thatsclarke]

 whereas the SW5-7 on a 1380 with 1.5 ratio rockers, L3 head and a single HIF44 

[Stevie W]

+1 for the above.

I installed an SW5-7 in My 1293cc A+ engine, accurately timed in with a vernier cam gear and duplex chain. The engine runs a fast road Minispares head and twin 1.25" SU's. I also have an Aldon yellow A+ dizzy and electronic ignition installed.

The tickover is smooth (for an old engine design and carbs) and it pulls willingly from about 1500rpm right up 6000rpm and the acceleration seems to just keep coming.

Cheers, Steve.

how do you know which aldon dizzy you need because theres alot of different ones, how did you know which one you need specifically for your engine? was it a 100AYV? did you need the vaccum advance? i didnt really want to buy a new dizzy, thats why i was thinking of getting the ACD RS or Evolution001 because they are £100 cheaper and i feel like the sw5-7 isnt getting an extra £100 worth of performance boost in comparison.
dont suppose you know how much bhp/torque youre getting in your 1293?
i didnt really want to fork out for a new dizzy aswell

Hi,

The dizzy was recommended by Steve Harris who originally set up the engine and it uses the vacuum advance system too. At the time the engine was giving around 82bhp.

The current engine is a different engine but with the same spec head, pistons and crank and this has never been set up on a dyno, but it pulls very well and I'd expect a similar power output. One of the jobs this year was to get it set up properly on a dyno but with things the way they are I'm not sure when I'm going to get round to this!

On the road, it pulls well from low revs and keeps pulling it up to 6000rpm, I've not taken it beyond this as there seems no point. Driveability seems very good and the throttle response is superb.

Sorry I cant answer all your questions, but all I was stating was the fact that the SW5-7 in my engine allows for surprisingly good pulling power and driveability.

Cheers, Steve.

Edited by Stevie W, 09 April 2020 - 06:29 AM.

[Shooter63]

Programmable ignition + injection. When properly set up this makes even the wildest of cams behave like docile puppies and also works wonders on fuel economy.

No It wont

[IronmanG]

Programmable ignition + injection. When properly set up this makes even the wildest of cams behave like docile puppies and also works wonders on fuel economy.

No It wont

Interesting I have been told by some engine builders/ suppliers that injection can make up for a cam that has a lumpy idle etc.
Can we follow this up a little? Any more input?

[evoderby]

“No It wont”

 

 

yes it will....but each to their own I guess.

[Shooter63]

Quite simple really, it's something called reversion, when you have a cam/cams with large opening and closing durations both valves are open for a long time and at low revs the inlet charge gets partially pushed back out of the cylinder ( you can see this as a mist of fuel above the ram pipes, which is called stand off) but the injector still squirts another batch of fuel in, this now causes the engine to run rich and you get that horrible burbling when the engine won't pick up cleanly. Now an ecu cannot cure this,with careful mapping you can take the worst out but you can't stop it or alleviate it. And this is the very reason I have taken the big cams (285 degree) out of my kit car engine and gone turbo so I get a nice smooth power delivery ( and quite a lot more obviously). If you want a better explanation phone Dave Walker, he owns the Emerald ECU company, really nice bloke and at the moment proberly not that busy due to our current situation

Shooter