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Wu Li
Registered User
Posts: 39
(6/8/01 10:55:47 am)
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Lumpy cams
Does a cam job actually increase power or just put it somewhere else in the rev range?
My mate was saying that a cam job doesnt actually give you any more power, it just repositions it.. Either more grunt down low or a power up high.
Is that true?
Daniel
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MechaMegloManiac
Registered User
Posts: 23
(6/8/01 11:58:28 am)
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Re: Lumpy cams
Well,yes and no,you can use a cam of the same specifications to move the power band,or,use different specs to gain more power,also,the power gain can be moved by using adjustable cam wheels.Unfortunately,cams are a constant trade off,
to have power high,you generally lose low and vice versa,though a cam could be designed to offer power across the board,it takes an awfull lot of time and money.
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20v
Registered User
Posts: 259
(6/8/01 12:14:07 pm)
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Re: Lumpy cams
This is why Honda invented VTEC to get around this problem. Toyota didn't do to bad with VVT on the first 20v but now they're combined both in the latest Celica's 1.8L 2ZZ-GE VVTLi that makes 140kW @ 7600rpm! Yowza that enough power to make any VTEC owner shake in their boots
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DR Z
Unregistered User
(6/8/01 5:06:15 pm)
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Lumpy cams
So do u recomend buying new billet cams or getting your original bam ground with lash caps.
I recon for a daily driver ground cams with lash caps would be the best choice but is the strength and reliability any good can someone tell me please?
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MechaMegloManiac
Registered User
Posts: 25
(6/9/01 1:19:15 pm)
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Re: Lumpy cams
Regrinding is fine.
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ae25nz
Unregistered User
(6/9/01 11:48:37 pm)
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regrinding?
just for personal knowledge..
if regrinding a stock 4age cam, do the cam retainers or anything else for that matter need modifying? shims obviously, but anything else?
thanx
mark
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MechaMegloManiac
Registered User
Posts: 27
(6/11/01 11:39:11 am)
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Re: Lumpy cams
No,the original base circle is retained.
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Bill Sherwood
Registered User
Posts: 15
(6/12/01 4:37:40 am)
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Re: Lumpy cams
Not quite correct - A simple regrind is where the base circle (the fat part of the cam lobe) is ground down to make a bigger difference between that and the top of the lobe (the pointy bit) bigger. and also by shaving away some of that metal it lets the profile get a little 'fatter', thus have more duration.
It's very definitely not the way to go for a 4AGE type head, as apart from needing 16 new & much thicker shims, on the shim-over type cam buckets that the 4AGE has you stand a much greater chance of the bigger cam spitting the shim at high revs.
The only way to go is to use the stellite method to make your cams bigger, and that involves taking in your current cams which have most of the lobe ground away and some exotic stuff called 'stellite' welded onto the lobes to fatten them up. They're then ground down again to the new profile. The base circle isn't touched at all, thus you can keep the same shims (though that sort of work is often done with a pardon-the-expression 'head job' and so the valves are often also re-seated, thus you'll need to re-do the shims for the valve clearances anyway.)
A plain regrind is maybe Aus$100 per cam, but the stellite method will be more like double & a bit to do. But if you work it out, it's probably cheaper anyway than getting 16 new shims made up (Toyota won't have thick enough ones, though some Yamaha & Honda bikes sometimes do - I have a few ('thin' ones) in my 4AGE as they cheaper than genuine Toyota ones.
Another alternative is to start from scratch will billet cams, but again they're often a bit on the pricey side.
Home page here
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ae25nz
Unregistered User
(6/14/01 2:11:41 am)
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yeah
that's what I's after.
the cam guys say you can regrind stock cams and they work fine. --- but the way i see things, without 'adding' to the lobe, reliability diminishes due to the large shims.
the reason i asked is, when i had a look at my cams, (if regrinding) there was no room for a thicker shim when the base circle is reduced. it would hit the cam retainer.??? (you'd have to see for yourself maybe) i'm probly wrong here, but it looks that way?
another idea i've heard somewhere is to machine the cam retainers and cam seats, (& just about everything else?) so the cam sits closer to the head which removes the need for thick shims. WHAT A MISSION!
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Bill Sherwood
Registered User
Posts: 21
(6/14/01 4:25:38 am)
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Re: yeah
The thicker shims will still be clear of the cam bearings. Still not a very good idea to do though.
(a very poor analogy is to look at the difference between a coin and a can of fly spray - Sitting both of them on their circular ends, which is easier to knock over? Yes, a little simplistic & exagerated but that's the priciple of why not to use very thick shims with bigger cams)
Not too keen, either, on that massive machining job you were talking about - It'd be a LOT easier & cheaper just to get shim-under buckets and be done with it!
Home page here Edited by: Bill Sherwood at: 6/14/01 4:29:27 am
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MechaMegloManiac
Registered User
Posts: 29
(6/14/01 3:49:36 pm)
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Re: Lumpy cams
Well,just speaking from personal experience,I have had 3 sets of cams ground,2 were regrinds and 1 was a billet,in all cases,the base circle was untouch,the billet was identicle to a factory billet at base circle,I mentioned the other approach to the engineers working my internals,they chuckled,said it sounds like a schoolboys tactic,there words,not mine.They do genuinely carry out mods for some very big names in the OZ race scene,if I were to mention there name,there would be no argument,but...others may no more.
Smuggla.
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Hoonda
Registered User
Posts: 82
(6/14/01 5:43:52 pm)
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oi 20v !
Honda have a B18C (1.8L) that does 149kw stock.
Thats only VTEC, not even i-VTEC, which produces even more.
So... quiver at that!
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MechaMegloManiac
Registered User
Posts: 31
(6/14/01 8:29:43 pm)
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Re: Lumpy cams
Spare me bad boy...no Honda makes that power,Honda are full of crap,only new skool kiddies believe power quotes,case in point: I raced a 118K/W CRX about 8 yearsago,it had exhaust...filter,blah blah...I had a bog stock SX 100K/W,paper filter,factory exhaust..I blitzed that poor fool by 3 car lengths B4 3rd...and,yes,he was most certainly up it,bouncing cut out
and still lost mucho groundo..please buddy,dont quote what you read in a magazine,it's crap 1ce it's on the street.
Smuggla.
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Wildcard NZ
ToySpeed Founder
Posts: 806
(6/14/01 8:36:20 pm)
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Re: Lumpy cams
I don't think Toyota figures are any more beleivable.
20v case in point.
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Bill Sherwood
Registered User
Posts: 22
(6/14/01 9:09:21 pm)
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Re: Lumpy cams
"I have had 3 sets of cams ground,2 were regrinds and 1 was a billet,in all cases,the base circle was untouch,the billet was identicle to a factory billet at base circle"
A plain regrind of a cam to make the lift and duration bigger must reduce the base circle - that's a physical fact.
"I mentioned the other approach to the engineers working my internals,they chuckled,said it sounds like a schoolboys tactic,there words,not mine."
It's a common procedure, and the only other correct way, apart from billet cams, to get bigger cams into your engine. If you've got a push-rod or rocker type valve gear then a plain regind is okay though.
"They do genuinely carry out mods for some very big names in the OZ race scene,if I were to mention there name,there would be no argument"
So mention their names then.
Home page here
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MechaMegloManiac
Registered User
Posts: 32
(6/15/01 1:58:46 pm)
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Re: Lumpy cams
There is absolutely no reason for the base circle to be touched,metal is added in order to change duration and lift,if the cam grinder know's his job,the shim clearance should not be changed,if the base circle is ground,there is no room for the required clearance,it's an arse about face concept and no cam grinder worth his weight in urine would perform such a modit's dissapointing you would even mention such a concept,except for the fact that you must cryptically bastardise every post I make,why do you see need to make things so complex?? It's really not that hard,are you scared of
people knowing more than you?
Mention there name?
The firm I deal with do not deal with general public,they deal with huge industry,diesel,sponsored high profile race teams.
They will not perform assemblies,nor dummy builds,yet,they deal with me,I have worked long and hard at building a rapore with these gentlemen,1 I truely respect,they dont take into consideration I have absolutely NO qualifications in engineering,they judge me on my requests,on what we speak of B4 each modification,on what Iam wishing to achieve,they take time to convert imperial to metric for me,then,my pissy little GE block is placed with megabuck machinery,my rods are treated 2nd to none,I specify clearance,it's set to spec,perfectly.Theres never any contention,no misshaps,cut corners,they are utterly professional and whilst you treat me as a fool,those who really matter,see me as an enthusiast,with an approach different to most,I'm lucky to have a foot in the door with them,I'm hardly going to give you even the slightest opportunity to have anything to do with it.
I told them that you said it was my fault the last engine went,
they set about finding what caused the problem,we now have a very good idea how it can be alleviated,do you?
Smuggla.
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alonzo69
Registered User
Posts: 88
(6/15/01 6:54:23 pm)
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Re: Lumpy cams
DONT BRING THAT SHIT HERE!
IF BILL OR MEGA MAKE A ANOTHER DEROGATORY POST HERE LOOK OUT FROM ME.
alastair@guyofyourdreams.com
icq : 101761410
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MechaMegloManiac
Registered User
Posts: 33
(6/15/01 7:14:52 pm)
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Re: Lumpy cams
Do you want fact or fiction?just keeping things real.
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Wildcard NZ
ToySpeed Founder
Posts: 811
(6/16/01 12:15:36 pm)
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Ok, heres the rules.
For Bill & Smuggla, welcome to our board first of all
However, we are not going to tollerate any type of sniping here, if you guys can have an intellegent debate, thats fine, if it degenerates, your posts will simply be deleted.
There won't be any arguements about this.
However, I welcome you to come here and share your knowledge, we're not going to delete posts even if factually incorrect, but we are going to delete anything, straight away, which we feel is not in line with the friendly nature of this board, so please don't waste your time.
We look forward to your input here, but please abide by our non controntational rules as we won't be making exceptions.
Edited by: Wildcard NZ at: 6/16/01 12:19:00 pm
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MechaMegloManiac
Registered User
Posts: 35
(6/16/01 12:52:48 pm)
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Re: Lumpy cams
Thats fair..least it's not the big skirt approach others have taken,quick ban him...woooo..he he...did you know that 1 of the other Toyota boards has sold out?? 1st it went from F/D only,to R/D...now it aint even Toyota..I geuss some people just want notoriety,cant have that by banning people and upsetting there friends...cheers.
Smuggla.
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Bill Sherwood
Registered User
Posts: 23
(6/16/01 11:18:04 pm)
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Re: Lumpy cams
"There is absolutely no reason for the base circle to be touched,metal is added in order to change duration and lift,if the cam grinder know's his job,the shim clearance should not be changed"
You are actually agreeing with me there - You just haven't read what I've written above. It's the first time you've mentioned 'adding metal' to the cam and so that's the stellite method I was talking about. A 'regrind' is where the metal is taken away (reducing the base circle) to make the lift & duration bigger, and hence is only used on rocker type valve gear.
"except for the fact that you must cryptically bastardise every post I make"
No, when you're right I don't comment. When you mentioned a 'regrind', that is a good recipe for valve gear disaster in an engine like the 4AGE, so to stop people from destroying their engines I cleared things up. By reading the post immediately under when I did that, it seems that it became obvious to the people that needed to know.
"I told them that you said it was my fault the last engine went, they set about finding what caused the problem,we now have a very good idea how it can be alleviated,do you?"
I am still waiting for an answer as to how a 4AGE making only 137ft-lbs of torque can break two con-rods. The ratty old 4AGE in my Sprinter makes up around that, and has done for about nine years without a problem.
"did you know that 1 of the other Toyota boards has sold out?? 1st it went from F/D only,to R/D...now it aint even Toyota"
Not correct - It's the www.4agze.com forum, and all they have done is added another forum to the originally Toyota-only ones, as many Toyota owners also own other cars types, for example me too. The owner of the forum originally owned an AE-92, but then he bought a genuine twin-cam AE-86 Corolla (in Australia,a very rare thing!) and so the original name of the forum wasn't entirely appropriate. He's naturally super-impressed with the RWD Corolla now.
Smuggler was kicked off that forum for creating trouble and arguing with many members, not just me. He was also caught posting many times under other names in the attempt to try to support what he said and discredit others. (not just me. There is a post by Austfwdcorolla on that subject showing all the IP address to prove it) This also happened on www.toymods.org.au.
Anyway, just to make things totally clear to the NZ members here, here's a bit more text and a picture that will help explain it all.

In the above pic you can the base circle, and how lift is worked out from it. So, there's two ways of increasing lift - either you make the base circle smaller or you add metal (stellite) to the top half of the cam lobe. (opening & closing ramps, flanks, and top of the lobe) By adding metal you can also increase the duration of the cam because the opening & closing ramps are more towards the bottom of the lobe (in that picture) and so the valves open earlier & shut later. That's a touch simplistic as not only can you get the opening & closing points 'bigger' and have more lift, but you can also make the flanks a lot fatter - The weirdest cam I've ever seen was on a mate's two litre Escort rally car. The damn cam lobes looked very much like they had TWO tops to them - The cam banged the valve open very quickly, then held it out near full open for a while, then banged it shut very quicky again!
Another weird one was the cams out of the Aussie Two Litre Brad Jones 4WD Audi racing car. It's a long story, but I bumped into Robbie Benson (taught by Jamie Aislablie, by co-incidence) in Albury, and he most kindly let me have a good look through the engine assembly room. Without a camera of course! The cams looked like those little red party sausages! They had 0.580" lift, to which I asked, "How long do the valve springs last?"
"About two hours," said Benson.
Not bad, eh?
Home page here
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MechaMegloManiac
Registered User
Posts: 36
(6/17/01 12:48:38 pm)
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Re: Lumpy cams
Well,if my standard 100 K/W engine made 137nm of torque,
then I can most certainly tell you,the blacktop makes more,not only that,if a GE can only ever produce that torque,
and torque is directly correlated to power,how can your beloved formula atlantic engine produce 250HP at a mere 9000
RPM?If 137nm equates to 134HP at 6800RPM,I dont know where you got that figure,but,I dont believe it's correct and it's certainly not applicable to the blacktop.
I dont understand what you mean by regrinds being dangerous for valve trains...or how any1 could ruin an engine by my comments,I didnt tell any1 to file them back in the garage,best you clarify your own inconsistencies,B4 you start with mine.
Smuggla.
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freezup
Registered User
Posts: 484
(6/17/01 1:35:15 pm)
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Re: Lumpy cams
Smuggla: 137ft-lbs not nm so that should be about 185nm.
andrew
| Toyota Trueno GT-Z |
MechaMegloManiac
Registered User
Posts: 38
(6/17/01 11:33:28 pm)
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Re: Lumpy cams
Cheers Freezup,mmm,too much on my mind at present,thx for the clarification and the face slap,best I go and concentrate on whats at hand.
Smuggla.
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Bill Sherwood
Registered User
Posts: 23
(6/18/01 6:19:09 am)
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Re: Lumpy cams
FWIW, here's an estimated dyno run on the Formula Atlantic 16v engine. The software is guaranteed to be accurate to within 5%, so even if the run is 105% of the real power the engine will make it'll be a rather strong one.
The other lines in the diagram are for a different configuration that I tested. (i.e. read the 'current' lines only)
You can see that it really starts to go at about 5000rpm, and goes very hard from 8000rpm up.
At 9000rpm, it'll be making about 145ft-lbs, or 196nm's.
At 6800rpm, it should make about 128ft-lbs, or 173nm's.
Home page here
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MechaMegloManiac
Registered User
Posts: 39
(6/18/01 2:11:42 pm)
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Re: Lumpy cams
This is how you concluded a max of 137??,a program on a computer?what perameters were supplied for this conclusion?
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MechaMegloManiac
Registered User
Posts: 45
(6/19/01 10:27:59 pm)
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Re: Lumpy cams
*sigh*,waiting...waiting...oh...and you finally got your wish,
Moto has banned me now too,so you can spread your
3rd hand redundant propeganda there also.By the way,nice work on the V8 comments too,how many V8's have you built,
"V8's have less bearings than inlines",dude,cant you count?
you crack me up,the more rope your given,the more nooses you tie.
Smuggla.
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GRPAW11NZ
Unregistered User
(6/19/01 10:36:46 pm)
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Software
Hey Bill,
Thats some nice software, can you post me a link to their web page (or other cool stuff like that)
Please & thanks, And who built your atlantic engine Jamie?
Nigel
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Bill Sherwood
Registered User
Posts: 24
(6/19/01 11:21:42 pm)
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Re: Software
An in-line 8 cylinder will have nine crank bearings, a V-8 has five.
An in-line 6 cyl has seven crank bearings, a V-6 has four.
Etc.
Nigel, I got the software directly from the US, www.performancetrends.com
It's pretty pricey though, at about US$500.
I am building the FA engine myself.
Home page here
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MechaMegloManiac
Registered User
Posts: 48
(6/20/01 11:43:31 am)
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Re: Software
You skirted my question,what perameters gave that result?
Cant believe you argue with me after all you have done is build an engine on a freaking pc...if any1 else did that,you'd
attempt to humiliate them,so keyboard racer,fill us in...
Dont you find it bizarre that people actually think you have built all these engines you dribble on about..you should be ashamed.
Smuggla.
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Bill Sherwood
Registered User
Posts: 25
(6/20/01 12:23:01 pm)
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Re: Software
The demo of it is free for all to download.
Home page here
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