Engine Trouble, Kent 298 cam!!
Turbo Mini Forums

Hi,

Had a bit of a dissapointing morning and need a little cheering up.

Went to Alan Jeffery rolling road this morning and he has completed an engine set up for me. (Shown below on printout:)



Basically the spec is 1330cc, Kent 296 scatter cam, ported and polished head, hiff44 carb.

Im a little bit dissapointed with the bhp, it is at the flywheel and from looking at similar specs on here i was expecting higher.

He also told me that to pass the MOT I am going to need to fit a new cam (at the cost of around £700) as it is a race cam and the emissions are too high with it.

The CO2 is ok, but hidrocarbons are around 1800, (needs to be 1200) i was told.(Its a 1988 reg car)

Can anyone help as im pretty gutted at the moment?

Thanks

Jon

your maing peak torque very low down for what is (to my mind) a rather racy cam. is it timed in correctly?

turbo 16v k-series 11.9@118.9 :)

Denis O'Brien.

That cylinder head would seem like it needs a lot of work who done the work on it the engine looks stiffled imo

Your RR operator slightly mis-informed you, the 1200 ppm HC is not mandatory. On cars with high overlap cams this is never achievable at tickover so the testers manual says

"Note: If a vehicle meets the CO requirement at its normal idling speed but fails the HC check, re-check the HC level at a high idle speed of 2000rpm. If the HC reading is 1200 ppm or less, the vehicle will meet both the CO and HC requirements.
. the CO requirement must be met with the engine running at its normal (low) idling speed
. do not use a cold start/cold running mechanism to achieve a high idle speed. Instead, apply light pressure to the throttle pedal."

http://www.motuk.co.uk/manual_730.htm
About 2/3 way down just below subsection 4 (holed exhaust).

The RR operator should have re-tried yours at 2000 RPM and (assuming it was OK at 2000 RPM) advised you of which MOT stations in your area actually know and work to the rules.

HOWEVER, 1800 is way high - I too would think cam timing..... How did you set it, vernier sprockets or offset key ??? How accurate were your readings when you set it - if you don't rotate backward and forward from peak lift (and TDC to set your timing disc accurately) it could be well out.

Or, is there a small misfire at tickover - also puts HC way up....

Schrödinger's cat - so which one am I ???

i'm thinking cam timing too.

with that cam in my friends 1330 it revved to 9000 and that had standard bottom end

Jack Jones

Hi,

I have messaged the person who i bought the engine off of, asking about cam timing etc so will let you know about that when he gets back to me.

The RR tester did take it up to 2000rpm also and he said the hydrocarbons went up, not drop as he was expecting??

Is it difficult/expensive to get the cam timing checked etc??

Thanks

Jon

Schrödinger's cat - so which one am I ???

Do you know for sure if there is a Kent 296SP cam in there?

Hi,

Im pretty sure its a 296, the guy i bought the engine off of is trying to help me sort the problem out and seems very genuine, he cant believe how little power it has as when he had it running he said it was a lot more.

It is a fixed cam pulley, the only things that have changed from when he had it is the distributor, carb (both hif44), and exhaust system.

The engine has not been touched which is why we are so confused??

Any help really appreciated?

Thanks

Jon

If it is on standard cam timing gear, I very much doubt that it is is timed in optimally, however the only way to really know is to check.

As above, if just on the standard sprockets the chances of it being right are slim.

But you will need to measure (the timing angles) to be sure.

Schrödinger's cat - so which one am I ???

What dizzy did you fit?

it must be well advanced to make max power at 6 k, when i run said cam it made max at 7300,timed in straight up

WWW.FORCE-RACING.CO.UK PLEASE CLICK HERE

Hi,

Does that mean that all of these problems could be down to the timing of dizzy, i.e setting the dizzy to correct degrees?

Wouldnt the rolling road tuner have checked this?

As far as i know there has never been a strobe light on it to check all of this??

Thanks

Jon

no, cam timing

WWW.FORCE-RACING.CO.UK PLEASE CLICK HERE

yep i agree cam timming needs checking, should make more than that, then again depends on the rolling road and how it is calibrated.

with a 296 should make peek hp way past 6000rpm.

my 1275 with a 276 my old 1380 head made 86hp at the flywheel, mind you it was crab at the bottom but went well past 3k though

always looking for them bigger bunches of bannanas

Im starting to think the engine dyno i use is far far far too high, mine made 110 at the flywheel with twin webers but then again the compression ratio for that dyno session was 13.4:1.

but even then i think 86 at the flywheel is very low i would expect that at the wheels.

Edited by Sam on 30th Nov, 2008.

whats the compression of the engine ?

if the cars for road use i would ditch that cam in favour of something a little More tame!

clearly the the cam timing is a light year out some 4 to 5 deg too advanced

also ignition timing needs to be sorted when the above has been sorted

my friends engine produced 72 bhp with a standard head and MG cam the bores & pistons on the engine are some 30 odd years old

who did you buy the engine off???

Jack Jones

Hi,
Looking at the graph, there's nothing wrong with a flat torque curve, but HP should be on a steady climb all the way to peak HP.
Is said above the head could be strangling it.
I'd personally check/get the cam timing right, then the ignition timing and re check fuelling. Last 2 on the rollers.
Until you know the cam timing is right you'd be wasting time/money elsewhere.
Cheers,
Gavin :)

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What dizzy did you fit?

But this has got a flat power curve with the torque falling all the way from 4.5k.

Something strangling this engine.

The thing with scatter pattern cams is that Cyl 1 is retarded, so if it was timed in conventionally at say 106, then the inner cylinders would be well advanced.

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

Still cant help but think that its a fairly mild cam, but what has happened to the lower part of the power run, it starts right on the money at about 4350rpm