Tuning Cam

[Stephen Carr]

Hi guys,


We stripped the eninge out of our seicento last week to clean it up etc,

it appeared that the rocker cover has been rmoved before and resleased with loctite,
is there any way of locating a serial number or anything to suss out if this is the standard cam or an uprated on


Thanks

Steve

 

[fingers99]

It's very usual to find gasket sealant on the rocker cover -- it's the only way of making them seal properly, even with a new gasket.

There will be a number stamped on the cam. Report back with that.

 

[Stephen Carr]

What benefits are there to installing a punto 75 cam in the 1.1 fire engine, how much should you spend on one and does anyone have on e lying aroudn they dont need I am thinking of using either one of these or stretching out to a more expensive one

 

[rallycinq]

A used P75 cam maybe worn leaving it with less lift than a new standard one.

Whatever you do with the whichever cam you use, make sure the head is clean, the valve stems aren't covered in carbon, and the clerances are spot on with cam timing also spot on.

Don't rely on the standard dowel being right, it might be, but check it.

Cheers

SPD

 

[fingers99]

And re-cut the valves, before you set the shimming.

I like the P75 cam -- unworn it makes the engine much more spritely. Important to check for wear, though.

I'd be inclined to run through all the other tuning stuff first -- 40mm TB, decent induction kit, chip, manifolds, exhaust. They're all cumulative.

While you will get something extra from a P75 cam, you really need a vernier pulley to get the best from it, and that's much more true (?) for a lumpier cam.

All this only makes sense if the engine is in rude health -- you should at least get a dry and wet compression test done, better still a blow down test.

To my mind, the most important tuning mods are suspension/tyre/wheel/brake ones. No point in arriving at a corner quicker if you have to brake earlier and go through it more slowly..............

 

[Stephen Carr]

To my mind, the most important tuning mods are suspension/tyre/wheel/brake ones. No point in arriving at a corner quicker if you have to brake earlier and go through it more slowly..............[/QUOTE]

Cheers for all that, with regards a couple of the items you mentioned


We are running a bank of 4x 600cc kawasaki carbs with a purpose made inlet manifold and pipercross or jetex trumpet socks ( i know they have there doubters on here) but been in deep conversation with a racer, a very successful racer who races a seicento with 600 carbs on and says they are great. but i know we have some setting up to do with them, apparently this will give approx 19hp , i cant wait to see this

We have ordered our new 100% programmable ecu from Canems with the above mentioned racers map already installed. reading up (this will start a conversation off) this will help to the approx value of 5hp getting it running properly etc, (i wait to see)

exhaust is the next question, i have been informed that a few autograss racers (quite well) use motorcycle cans to finish off there exhaust system, i have my doubts but i dont know about exhausts

Does anyone know of the most cost effective exhaust manifold to get.

then its moving into the engine and i dont even know where to start there,:bang: head skim £30 then silly money.


Cheers

Steve

 

[fingers99]

The main issue with bike cans is that they're usually stunningly heavy. Otherwise they're just absorption type silencers. Somewhere there's an Australian Off Road site with some ideas.

I'd think that ITBs would give similar performance gains across a wider rev range than carbs -- often it's important to have decent throttle response lower down the rev range, and there's really nothing an ECU can do with carbs.

For the exhaust mani, you're really limited by what's available out there -- IIRC, there are only 3 manufacturers.

 

[Stephen Carr]

The ECU is only controlling the ignition side of things, i wont pretend to understand it all as my brother looks after all that,


ill lookinto exhasut stuff

thanks for all

 

[James7]

Anyone reccomend some good aftermarket / higher lift cams? Ones that wont need a remap to sort out the idle and fueling so basically a non-lairy cam

 

[fingers99]

Lumpy cams won't work well with a plenum system (you'll loose the idle) and will need a re-map/new chip (and vernier). C & B do them, but they're anything but cheap. Unless you're going bananas with the rest of the engine, stick with the P75, shim it properly.

Best cheap engine mod is a Punto 60 engine.

 

[James7]

Lumpy cams won't work well with a plenum system (you'll loose the idle) and will need a re-map/new chip (and vernier). C & B do them, but they're anything but cheap. Unless you're going bananas with the rest of the engine, stick with the P75, shim it properly.

Best cheap engine mod is a Punto 60 engine.

I dont want to have to shim any cams

Just want something i can stick straight in and see a slight improvement, and were can i get a bigger TB?

 

[fingers99]

Shimming is an essential part of the maintenance schedule. Any new cam will require it, even the P75. If you think about it, the valve clearance provides the final bit of the cam timing, which is what you're paying loadsamoney for. It's no big deal, but confuses the hell out of a lot of people.

For bigger TBs, -- I can't remember what your car is -- see the thread "Tricker stopped making............." for SPI cars. For MPIs, Arc and Kritip have made various suggestions.

 

[James7]

I know a fair bit about cams, but on other cars i have never heard of shimming? Even when fitting new cams at the garage i work we never "shimmed" a cam? And i know hundreds of people with 106 / Saxos who have fitted alsorts of cams from Newmans PH1s,PH2s,PH3s then kent fast road, catcam 708s etc none of them shimmed anything?

 

[fingers99]

I know a fair bit about cams, but on other cars i have never heard of shimming? Even when fitting new cams at the garage i work we never "shimmed" a cam? And i know hundreds of people with 106 / Saxos who have fitted alsorts of cams from Newmans PH1s,PH2s,PH3s then kent fast road, catcam 708s etc none of them shimmed anything?

I know nothing about these strange French engines you mention. Maybe they have hydraulic tappets? Maybe they have screw adjusters for valve clearances?

Anyroadup, the 8v FIRE engines follow the glorious tradition of the DOHC FIAT engines in having shim over bucket valve clearance adjustment (itself a simplification of the technically superior but less adjustment friendly Alfa shim under bucket system). The bucket sits on top of the valve, the shim locates into it, the cam bears on the shim.

Most Japanese bikes have the same system.

It's more accurate than any hydraulic system (especially at high revs), lighter and more robust than screw adjuster ones, and easier to work on than the (classic) Alfa system.

Fairly well detailed in the Haynes Cinq manual (and in the Haynes Mk1 Punto one which is on rapidshare).

If you're near south central Liverpool, you're welcome to pop in and take a peek. Might even sell you a cam!

 

[rallycinq]

I know a fair bit about cams, but on other cars i have never heard of shimming? Even when fitting new cams at the garage i work we never "shimmed" a cam? And i know hundreds of people with 106 / Saxos who have fitted alsorts of cams from Newmans PH1s,PH2s,PH3s then kent fast road, catcam 708s etc none of them shimmed anything?

mmmm, did you time them with a vernier?

Cheers

SPD

 

[James7]

Yes the TU engines do have hydraulic tappets?

And some people i know have used a vernier pulley, but the majority dont. Just put the cams in aswell as new valve springs etc etc then if it's a PH3 or a 708 then they get a remap to sort fueling/idle out. Other less wild cams are just left and work without a map.

Is shimming on the Punto cam for a seicento a DIY job? Or would you have to consult a machinist? Or does anyone on here sell them pe-shimmed or do it on a exhange basis?

 

[fingers99]

Yes the TU engines do have hydraulic tappets?

And some people i know have used a vernier pulley, but the majority dont. Just put the cams in aswell as new valve springs etc etc then if it's a PH3 or a 708 then they get a remap to sort fueling/idle out. Other less wild cams are just left and work without a map.

Is shimming on the Punto cam for a seicento a DIY job? Or would you have to consult a machinist? Or does anyone on here sell them pe-shimmed or do it on a exhange basis?

Drop the head off with the cam manufacturer's recommendations -- or bring the car round -- and I'll do it. Some people grind the shims (in which case you're talking engineering) but providing it's within the range of FIAT shims, you can just buy them over the counter. I think Fluffy sells them for about £3 a hit and generally you can get away with re-using many of them. Some Volvos use similar shims.

So, yes, it is DIYable. Much easier with the cam belt off, so best budget for new belt and tensioner, rocker cover gasket, water pump optional but recommended -- use a genuine FIAT one, some of the pattern ones are pants, vernier cam and visit to RR for best results.

But should -- I think -- be the final mod, after TB, inlet port matching, chip, exhaust and mani.

Bet there are lots of TU folk trying to replace the hydraulic tappets with solid ones!

 

[James7]

Not as far as i know, even people with 200bhp+ NA and 300+ forced induction keep hydrualic?

And what about headwork? Could i just take the head to QEP, Hiflowheads or LAD engineering?

What gains does the cam over standard? And this whole shimming thing sounds very risky? Actually grinding part of the cam down doesn't sound like something i would want to do DIY. But i don't really know enough to make a decision

 

[rallycinq]

You grind the shim not the cam.

If you are not sure what you are doing, then don't do it.

I am convinced that people carry out mods and are too ashamed to admit they don't work.

Cheers

SPD

 

[James7]

You grind the shim not the cam.

If you are not sure what you are doing, then don't do it.

I am convinced that people carry out mods and are too ashamed to admit they don't work.

Cheers

SPD

As in dont work outright, or dont work as in no gains from it?

And i wouldn't even think about doing anything like this, fitting the cam is one thing, but this is over my head.