Need info on highlift cams

[Calum122]

Turbo cars aren't fussy about cams so long as they aren't too wild. Also remember high lift cams will cause excessive wear to the valve guides.

There are some great books available should you wish to know more. Modern Engine Performance Tuning by Graham Bell gives a basic overview of what to look out for.

I would say I am fairly smart and whoosh, straight over my head.

Graham Bells Forced Induction Performance Tuning is an excellent read that I finished the other week. His opinion on cams was interesting.

Edited January 12, 2016 by Calum122

[Whitenoize]

Can you read these books online at all? That forced induction one is 150 quid

[Calum122]

Nah I looked for months and managed to pick a copy up for £25 believe it or not.

The other books are equally good.

[5e colin]

Turbo cars aren't fussy about cams so long as they aren't too wild. Also remember high lift cams will cause excessive wear to the valve guides.

There are some great books available should you wish to know more. Modern Engine Performance Tuning by Graham Bell gives a basic overview of what to look out for.

I would say I am fairly smart and whoosh, straight over my head.

Graham Bells Forced Induction Performance Tuning is an excellent read that I finished the other week. His opinion on cams was interesting.

i always see peeps wanting them but there never raising there rev limiter so whats the point in fitting cams in the first place

[AdamB]

Turbo cars aren't fussy about cams so long as they aren't too wild. Also remember high lift cams will cause excessive wear to the valve guides.

There are some great books available should you wish to know more. Modern Engine Performance Tuning by Graham Bell gives a basic overview of what to look out for.

I would say I am fairly smart and whoosh, straight over my head.

Graham Bells Forced Induction Performance Tuning is an excellent read that I finished the other week. His opinion on cams was interesting.

Turbo motors are fussy about cams, especially if the valve sizing is wrong. I see it time and time again where people think they've maxed stock cams, but in fact its flow through the valve seat that's limited. Turbo motors will idle rough, poor low-mid range performance due to poor flow at low valve lifts.

It's not high lift cams that tend to cause much wear, yes they do wear but they wear the nose of the cam. It's more the ramp rate that will kill everything else.

Don't believe everything you read in books, I referenced some stuff from the books you mentioned for a university project, basically got told it was all bollocks.

The information you want to know, isn't exactly going to be published for the world to see

I agree with Colin, it seems most tuners don't tend to go anywhere near even 8000rpm, be even worse with aftermarket cams with more duration with not having the wider powerband.

[Calum122]

Can't argue that Adam, but what you're saying is to do with flow, not lift.

Of course high lift has an effect, but as you say if the flow isn't right then that will cause problems. And what happens if the flows corrected, would the higher lift cam still cause so much of a problem. I can appreciate at idle where there is no additional pressures involved.

And again back at you? Are turbo cars fussy about cams.

Take the Starlet. So I am led to believe they run the same cams on the turbo as they do on the N/A right? Yet the turbo has no problems idling, nor does the N/A.

Obviously I appreciate lower compressions and different levels of tune.

Okay what about the otherway round. What if we took a turbo car with turbo cams. The mitsubushi evolution lancer for example. I have seen the lift ans style of those cams and they are aggressive, but very mild lift. Very mild. I bet they are different to the N/A lancer and then would Turbo cams work on the N/A car?

I bought the Graham Bell books because he is well respected and I am surprised to hear about your university not agreeing. Graham does say a lot in his books. I do not advocate. I do this and I do that. Implying that is his opinion.

I know tuners (two stroke) who very well rate his books.

I don't know about any of this so please excuse me. I am simply regurgitating what I read in a book as I say. A book that seems to have a reputation of being factual so perhaps I am mislead. I would like to think his books are truthful up until his opinion. Of which I still take for fact which I probably shouldn't.

Yeah I guess you're right about not believing everything you read in a book. But only by reading his, and other books, will I be able to understand, correlate the facts and fiction. I won't ever get the opportunity to work on a variety of cars. Only the ones I own. I will have to take what people like yourselves say. And I respect your opinions as you have the cars to back up your word.

Whether fact or fiction I still agree with the consensus that the cams on the starlet are up to the task of delivering results.

And I say not fussy because that's how it is read in the forced induction book. However he does say all the same rules apply to an N/A. But I think we can see that other factors play into turbo cars meaning it is no longer the cheapest way to make power.

Hopefully that makes all sense and I do get what you mean. It's good to see what others think.

Edited January 13, 2016 by Calum122

[AdamB]

Try answer as best I can lol.

Flow into and out of the engine is a function of many things such as valve lift (lift at the valve not the camshaft lift as this is usually what's referenced by cam manufacturers), lobe centreline angle, rocker ratio, compression ratio etc etc.

This is what's usually known as "Volumetric Efficiency" ie how well the engine breathes.

The higher lift cam will still cause ill affects due to the nature of it's specification.

Turbo motors are usually pretty fussy with camshaft selection, again this comes back to volumetric efficiency, if you looked at the torque curve of a forced induction motor and compared that with an N/A you'll see what I mean. The N/A engine has a much flatter torque curve and can sustain it for longer.

Regarding comparing turbo Vs N/A starlets, the reason why is down to something called "dynamic compression", if you ever venture into N/A tuning, this is why it is suggested for wild camshaft profiles that the compression be raised due to the increase in valve overlap. That as well as different mapping will help the engine idle. The main reason why Toyota kept the same camshafts was likely down to cost, why would they want to spend more on adding a different camshaft profile to the same line of engine? The extra cost in tooling, manufacture and then testing doesn't make sense.

The reason why the 5E-FHE engine has different camshaft profiles is because it was sold in a different market, and hence the emission legislations would have been different to what we get over here in Europe.

Yes turbo cams will work on a N/A car, but again it comes down to the profiles etc, I'm not going to sit here and bullshit, but I can't tell you what a turbo profile will do on a N/A engine because it will vary depending on the profile. I have heard of it happening before, although for the life of me I can't remember which engine.

I was under the same impression as you mate, I have had the Graham Bell books for many years, and I used it for referencing as I was designing a piston to go into the Honda K20 BTCC engine. The chap who I done the design for is probably the most successful engine designer I know, who has a span of world championships from F1 engines to powerboat racing. So who am I to argue that? lol.

For reference I'm not saying that what is written in the books are complete bullshit, but from what I've been told regarding the design of components, in my case pistons, wasn't very helpful. Like I said, people either write books about their experience, but may not be in "the loop" to know what goes on inside the likes of F1, BTCC, WTCC, Moto GP etc engines. And those that do, aren't likely to share much of their knowledge, why would they because this takes away any competitive edge that they/the team has. In 10-15 years time or so you'll probably find more books will come out that will detail how the Mercedes F1 engine has dominated F1 over the last couple of seasons...

The camshafts on the Starlet is a differing thing based upon opinion. I see it as that the camshaft specs are fine, but since the E series engine was designed for economy, as Toyota's 4AGE was the performance varient, the valve sizing is a bit wrong. The engines takes use of something called "internal EGR" , and this is bad for performance, with diluted intake charge.

I've been in the tuning game, and I now work for one of the largest manufacturers in the UK so I see/ have seen both sides of the coin regarding why things are done in certain ways.

The trouble is, is that manufacturers spend millions (and I mean millions), designing, testing, validating engines, and what people try to do is take away the "streetability" and turn their cars more into race cars. Increasing performance by like 200%, or even more! Some engines (not all) aren't designed for this at all, to put it simply.

Just like to say that what I've written is my own opinion, everyone has their own opinion on how they validate things, and do things. Sometimes there's no right or wrong answer, but more so a compromise.

I hope that makes sense, should be some terminology there for you to Google and get more of an insight to

Edited January 14, 2016 by AdamB

[Calum122]

A very well educated response. I like it. Yes unfortunately I did not study engine design at uni, computers unfortunately, but I understand the principles of what you're saying.

I was going to argue so points but you a lot of what you say makes sense, and it's kinda obvious. For me it is usually the obvious things that I miss lol.

I read on here that the Starlet valves were the achiles heal in terms of tuning becuase of said diluting. Although I didn't realise this was an EGR issue. Isn't that counter intuitive though as I thought an inefficient burn was worse for the environment than a clean burn. I.e. The addition of exhaust fumes to a fresh charge can prohibite the propagation of the combustion flame and cause an increase in nitrates found in the exhaust emissions, which was said to be worse than the carbon dioxide releases.

Again I am only on my second book and no doubt am mistaken. You can lead a horse to water right?

It's an interesting topic and my only question is.

Graham and books tell you what to look out for.

But how can I, the mere mortal possibly test for such tolerances and variances that they divulge. It makes for a nicr bed time.story but ultimately it comes back to something Colin said the other day.

People like me will only be fitters. I am not a mechanic and.never claim to be. To be fair mechanics doesn't interest me too much but fitting shop bought components very much does. Ultimately it's going to be down to choosing and assembling the right parts. Then having it mapped accordingly.

Surely that is as far as any 'tuning' i can hope to accomplish. Could be wrong though.

The one thing Grahams book do say is how to avoid wasting money on unnecessary components for most modern cars on mild tunes.

Edited January 15, 2016 by Calum122

[AdamB]

Yeah Starlet heads from calculations and research I've done is where they fall down and like I said, because of this internal EGR occurs.

You're correct in some ways with what you're saying, I won't go into too much detail because it gets confusing really quickly when you start talking about properties, atoms, and atomic weights of air etc.

This should clear up your question though:

Yes Nitrogen Oxides, known as NOx are considered more harmful to the environment than CO2, however, NOx is only produced with something called "combustion dissociation", off the top of my head as it's been a while, but it happens at something pretty high, I want to say around 1200 degrees C, which a petrol engine combustion temps shouldn't get near. This is a lot more common in diesel engines because of the lean air-fuel ratios they run, and hence greater combustion temperatures, this is why you will find NOx sensors are commonly found on diesel applications rather than gasoline, especially on those engines which conform to the latest emission legislations.

I hope that makes sense?

I'm not saying that you shouldn't be buying books, or believe what is said in such books, but I can only speak on some of my experience. Their good books for those looking to brush up on knowledge and to gain an insight, I guess from my point of view with the level of detail that I go into, books just don't cover it.

Like I said there's nothing wrong with looking at these books, as they do provide some good ideas, and explanations which you could use on your own car, but I would say don't use them to come up with an idea from a clean sheet of paper.

With your experience, it gives you a good insight into what parts are good, and what's not worth the money, which is always a handy tool to have at your disposal.

Just to add as well, some of the gobble that you read on the internet as well should be taken with a pinch of salt, you never know the person on the other side of the screen, their background, knowledge etc.

Edited January 15, 2016 by AdamB

[Calum122]

Yeah I get what you are saying totally. Thank you for the explanation. Hopefully it's of as much use to me as it will be for someone else.

I was never looking to be 'big in the game'. As much as I would love to do that I wouldn't want a passion to become a job.

Cheers again!

[srferreras]

There are many theories, I searched results. 297whp at 1.1. I recommend changing cams for these engines designed for the economy