Technical Cams

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Technical Cams

Yazza54

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Thinking of going for a gsr induction and cams upgrade pretty soon...who manufactures fast road/rally cams or would be willing to re-profile cams for the 1.6 16v stilo?
Do C&B do them?
 
As I told you on PM.. CB cams are the best not regrinds and built specifically for the engine..its just hassle getting hold of them..:)
 
why would a manifold render a cam change useless?

its all too technical for me to understand fully, i was in the middle of a conversation between a group of tuners and exhaust makers the other night, and this is what they was all talking about, i will try and get them to explain it too me in a way i can remember and type :eek:
 
its all too technical for me to understand fully, i was in the middle of a conversation between a group of tuners and exhaust makers the other night, and this is what they was all talking about, i will try and get them to explain it too me in a way i can remember and type :eek:


please do :) doesnt make much sense to me :confused:
 
do you intend to fit a 4 branch manifold in the future? if so then off the shelf cams will be no good for you.

there is a 1.6 stilo gsr kit in classifieds ;)

Sorry but that is wrong. As a change of cams will allow the engine to breathe better, if you then change the restrictive air intake and change to a 4 into 2 into 1 exhaust manifold it will make better use of the cams as the air is able to get into the engine faster and it is also able to get rid of the waste gasses better as well. the cam timing might need to be altered slightly by use of a vernier pulley to make best use of the better breathing and also some time on a rolling road so that it can be set up properly.
 
Sorry but that is wrong. As a change of cams will allow the engine to breathe better, if you then change the restrictive air intake and change to a 4 into 2 into 1 exhaust manifold it will make better use of the cams as the air is able to get into the engine faster and it is also able to get rid of the waste gasses better as well. the cam timing might need to be altered slightly by use of a vernier pulley to make best use of the better breathing and also some time on a rolling road so that it can be set up properly.

Wrong interprataion of the use of vernier pulley.

Also it depends on the cam characteristics how the exhaust manifold has got to be.
 
If you have vernier pulleys on both inlet and exhaust cams you can dial the cam in to suit the pulsewave characteristics of the inlet and exhust systems to give better cylinder filling and scavenging of the waste gasses and you can also dial the power high in the rev range giving a narow powerband that needs to be reved to get the best out of it not good for road use, or you can set it up for a better spread of torque which is better for road use.

I was mearly saying that the statement made about aftermarket manifolds not working with off the self cams was not true, and tried to explain it in a relativley simple way.
 
You will never get very good results with an aftermarket of the shelf cam and an aftermarket off the shelf manifold. This is fact.

Hmmm, not so sure that's entirely accurate Peter, a very sweeping statement. An awful lot depends on the engine and the 'age' of the technology. I am sure that what you're saying is true for modern engines but take a good old fiat/lancia twincam - let's say a 2 litre 8 valve integrale - take an off the shelf Kent/Guy Croft GC3A or even a Strada 130 inlet camshaft on it's own (matched with a vernier) and the more agressive cam gives an immediate improvement.
Match that to, say, an off the shelf CSC exhaust and you will get good results.

However, I don't dispute that in more contemporary engines it will be more difficult, but not impossible, to get good results with off the shelf parts. I suppose in part that explains why re-mapping is so successful.

So off the shelf parts still have their place in tuning, I guess you just have to be choosy where you get them and what you buy :cool:
 
Well done abzstilo someone that understands what i was trying to say :worship:

Plus you cant beat a good old debate on forums thats what makes them so good

Modern engines may be more sesitive to changes due to the tighter emission controls put on them but a cam and manifold plus a remap and rolling road setup from a reputable company will still always produce better results than just a cam with a standard cast manifold...
 
why would you want to mess about with vernier pulleys and stuff when you can just get a cam machined right in the first place to match a manifold that is also right:confused:


Cost is the simple reason, cam duration is the main thing that is different from a factory spec lift might change a bit but then you start getting into problems of valves getting a bit close to pistons and if the angle of the opening and closing side s of the cam are too aggresive can cause valve bounce which will lead to problems and poor runningthe engine to not run very well. Custom ground cams are better suited to race engines where the are running for relativly short time and are also stripped down more often than a raod car. So off the shelf cams are designed to give more performance and keep the engines reliabilty.

As for getting a custom made manifol that can also cost a fair bit as you would need to tell the builder what you were using the car for and how you would be driving it eg for road use a 4 -2-1 manifold equal length primary pipes would give a better spread of torque and developing the manifold to give good flow and power could take a bit of time as there are a lot of variables to take into account such as diameter of the pipe lenght of the primary pipes then you have to do the same for the secondary pipes as well.

Which is why you are better just getting an exhuast and cam from reputable manufacturers as they have been in the tunning game for a fiar bit and know what they are doing and have done all the leg work and will know what work well with each engine.

As for using vernier pulleys they are used to just fine tune everything as standard pulleys are mass produced and might not be 100% accurate with their timing marks, as another example the good old A series engines timing marks can be as much as 3 deg out which is a fair amount! and by careful setting up using a dial test indicator to find the true tdc and by using a vernier pulley the cam can be timed in perfectly. Thats why when you by a cam kit they come with vernier pulleys, it may take a bit more time to set it all up properly but once it is the engine will run all the better for it and you will get more power where you need it in the rev range as well.
 
No not designed to suit the manifold it is just there to get he exhaust gas out, the performance cam is designed to get more of the exhaust gas out by holding the valve open longer. They may well be tested on an engine with a cast manifold and show good gains. When you then change the manifold to a free flowing tubular one that is designed to give a good comprimise between power and torque by using a 4-2-1 design the engine will be able to breathe a lot more efficiently if tied in with a good freeflow air filter thus producing more power and torque.

Any way i think i have now said the same thing enough now so i bid you all good night. :bang:

And please lock this post :)

Ps: For the initial poster get the C & B Cams as they are ace then get a nice SS manifold when you can and a remap your car will go so much better if you do. and remember to upgrade your bake pads as well since you will be going faster :p
 
No not designed to suit the manifold it is just there to get he exhaust gas out, the performance cam is designed to get more of the exhaust gas out by holding the valve open longer. They may well be tested on an engine with a cast manifold and show good gains. When you then change the manifold to a free flowing tubular one that is designed to give a good comprimise between power and torque by using a 4-2-1 design the engine will be able to breathe a lot more efficiently if tied in with a good freeflow air filter thus producing more power and torque.

Any way i think i have now said the same thing enough now so i bid you all good night. :bang:

And please lock this post :)

Ps: For the initial poster get the C & B Cams as they are ace then get a nice SS manifold when you can and a remap your car will go so much better if you do. and remember to upgrade your bake pads as well since you will be going faster :p

you obviously have no idea who oldschool is, or what he does:p
 
you obviously have no idea who oldschool is, or what he does:p

Sorry Red but BB is quite right in what he's saying about cams/heads etc.
Peter has a different view from the post he's made on the topic but in this instance they are both correct, from a certain point of view. I am reasonably confident that Peter wouldn't disagree with the point I made in my earlier post about 'old school' tuning, the difference being that we're in a different technology market today.

In an ideal world all performance parts would be bespoke but they're not (as that'd be b*ggeringly expensive) hence the off the shelf market which we all know and love.

We all know that a performance manifold will help get the gases out and improve the breathing of the engine (but arguably that only works if you increase flow through the rest of the exhaust system) that's not in dispute, but matching cams to manifolds sounds like a fairy tale to me. Yes, there would be benefits matching performance cams to a performance inlet and exhaust manifolds,that's undeniable.
However, even today, an experienced tuner will still get damn good results with aftermarket cams on an otherwise standard engine - fact!

Verniers traditionally allowed for optimum timing before modern engine management systems came along but today those management systems possibly allow more scope to tweak an engine without having to change the cams.... or anything else for that matter. However, I'd have thought a responsible engine tuner would still use verniers to optomise the timing of new cams in an engine. Every single performance engine I've built (and that is several) has had vernier pulleys as fine tuning is soooo much easier that way.

But none of those engines I built had modern ECUs which is why, to be clear, neither BB or Oldschool are wrong as there is no right answer.... this is more about tuning philosophy that tuning practicality. When I win the lottery we will prove both points of view are right and that no-one is wrong, but until then I guess we're going round and round in circles on this one ;)
 
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