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I am interested in pushing a little more HP from my 1380. Spec as follows:

Stage 4 head
285 cam
Twin H4s/JS pancake filters
Maniflow LCB + Stainless RC40
Powermax 73.5 pistons
Lightened standard S flywheel/orange clutch
Duplex gears
Electronic Metro Distributer
1.5 Purple roller rockers (note colour!)
4 sync C/R 1128 gearbox.

Had a rolling road and managed 67 at the wheels. Pulls incredibly well throughout for what it is but I wondered what the next step is to extract a bit more power (no turbos or similar) I often hear 100bhp at flywheel and would like to reliably squeeze a bit more if I can. Cheers. Mark

to me and i not no engine guru in the slightest , but 67bhp on that spec sounds low, did the rolling road garage say what you could do

1 thing i would say is to get a decent dizzy, aldon, 123, or maybe a specialist components dizzy-less set up.

there is not much in the normal aspirated engine you have not uprated or changed,

who was there head modified by,

Hmmm. The horsepower does look to be rather low for the spec you have.
An associate has a 1380 and his motor churns out close to a 100hp. Mind you, it is a genuine John Cooper conversion.
Was the cam timed in correctly during the build.?

what rpms are the peaks at?

High final drive ? and did he take the reading in top gear ?

InimiaD wrote:Hmmm. The horsepower does look to be rather low for the spec you have.
An associate has a 1380 and his motor churns out close to a 100hp. Mind you, it is a genuine John Cooper conversion.
Was the cam timed in correctly during the build.?

I agree. Using standard timing gears with a hot cam is hit-and-miss. The cam must be set accurately.

-Have the pancake filters got a proper mounting plate, with a nice radius into the carb? -If not, then bin them.

It does seem you're missing 20hp somewhere....

Don't worry about flywheel hp.
Unless the engine is measured on an engine dyno, then the figures are 'calculated'.
What's measured at the wheels is what you're using.

Ok. Tell me more. I am astonished that the timing on a car that runs and pulls very well throughout the range could see a dramatic change in power by changing the timing gear. What kit would I benefit from the most?
The pancake filters are something I have not even considered as far as radius etc. Can you explain how I can improve things.

Thanks for your input. Mark

the timing can bump up the bottom end at the expense of top end,

With the timing of the cam not accurately set, you tend to 'soften' it's effect, which as Mini13 says, can improve the bottom end torque, but will kill the top end.
-The timing doesn't need to be very far out, -a few degrees is enough ( 1deg at cam is 2deg at crank: cam rotates at 1/2 engine speed).

First you need to measure the timing to see if it is correct or not. The usual method is a degree wheel mounted on the crank, and a DTI (dial gauge) on the top of the No. 1 inlet push-rod.
You will need the timing data for the camshaft.
If you need to change it, then Vernier timing gears are the best bet.

Pancake filters can cause problems in several ways: The standard type filters are horizontally mounted above/around the carb, with the short aluminium connecting pipe to the carb inlet. This pipe acts like a ram-pipe, so 'stand-off' (the reverse pulses in the inlet tract) are contained 'in' the carb, so you're not spitting fuel/air back out of the carb, which can cause the mixture to run lean at certain revs, losing power.
If you remove the connector pipe, and fit the normal type pancake filter, you get a sharp corner at the mouth of the carb which creates a restriction to flow (the air doesn't like going round a sharp corner). Also you can suffer the fuel 'stand-off' problem. A short ram pipe in the filter can help, see:

http://www.minispares.com/Product.aspx?ty=pb&pid=32925

Also, the pancake filters tend to be rather thin, so the 'back' face tends to be a bit close to the carb mouth, which causes a restriction, and makes lots of noise!

But, having the mounting plate between the carb and the filter made from 6mm thick alloy, you can have a nice blend radius into the mouth of the carb (and you move the back face a bit further away. -Although this is not perfect if you are getting lots of fuel stand-off, it does improve things almost as much as the ram pipe. -Some of the K&N type filters have this radius moulded in.

Unless you fit heat shields and ducting, pancake filters also tend to draw in warm/hot air from the exhaust manifold/ back of the engine. Which also reduces power.

Probably the best set-up is an induction kit
http://www.amazon.co.uk/Typhoon-Inducti ... B000AP6RG6
(-OK it's for a BMW Mini, but you get the idea)