Fiat Abarth 130 TC inlet cams

[Hamish]

:D I don't know if anyone might be interested, but I'm about to rebuild a head to go on my Volumex coupe. I've sourced a couple of second hand but low mileage inlet cams from a Srada 130 TC. I'm fitting one to my VX and have undertaken to find a 'good home' for the other. price will be about £50 plus postage - a lot cheaper than getting cams ground!!
Full 130 cylinder heads also available from same source.

[DavidG]

What kind of profile does this cam have? I've been on the look-out for an IE inlet cam for my volumex (as noted in Guy Croft's book) ...

[Will]

I know of only one FI volumex being built, the owner used a 40/80 inlet, and a Beta FI on the exhaust (has dizzy end drive).
Guy's name is Nathen Dalhammer, he has since sold the car.
What FI system are you using?
-WIll

[Be-All VX]

I have Nathans FI Volumex, it is using a Saab fuel injection with a custom made intake adapter for the throttle body/ injectors. The car pulls hard all the way to the rev limiter (have hit it once or twice!). I get about 8 or 9 psi of boost. The car really moves!

[Will]

Hey, (got a name besides Be-All?)
I'd really like to take a look at that intake, can you shoot some pics?
I was thinking of casting or electroforming my own, I just haven't decided between Bosch or Lucas injectors, or whether I should go for a TBI unit.
I have a little less space to work with singe it's going on an ABARTH blower, which is about two inches wider than the stock Vx.
-WIll

[Hamish]

:lol: Sorry all, been away on holiday hence lethargic reply..... I'm not too sure of the specifics regarding the 130 TC cam but i have been advised (by Guy Croft himself no less!) that the 130 cam is better (more duration perhaps?) than the beta ie cam.
I'm almost definately going with a sidedraught rather than FI - simply because I understand carbs..... sort of!
I would also be interested in seing piccies of the VX fitted with Saab FI.
Hamish

[Will]

Is that conjecture, or has Guy Croft measured the cams?
I ask this because he also states some cams are "better" than others in his book, and cites horsepower gains, when measured in actuality they are identical within 2 thou and 1 degree of cam rotation, functionally equivalent for all intents.
To the best of MY knowledge, Guy Croft has never undertaken any serious effort to measure, degree, or ascertain the lift integrals of the TC family of cams. I tried to get him involved in determining this, and got snubbed. I suspect he's afraid his mystique might take a hit.
If he's actually got data, I'd love to see it. If he's just speculating, I want to make sure I don't include any of his unsubstantiated hypothesis into the body of work I'm putting together.
-Will

[Hamish]

:roll: Hmmmm - I'll bow to your undoubted expertise on this one Will, your guess is as good as mine when it comes to speculating what Guy Croft has or has not done with cam profiles and it's something I know naff all about - I bow to the expertise shown by the competition history of his engines and look forward to the impending arrival of your weighty tome... If someone with his credentials tells me it will work in my engine I'm inclined to believe him.
You could always contact him directly via his website (www.guy-croft.com) and ask him about what tests he has done yourself!
In the meantime - I'll go with the 130TC cam.

[Will]

Hamish:
I think you may have missed the point, which is that I've found several inaccuracies regarding cams in Croft's book, and finally undertook to measure them out of frustration at the direct contradictions contained therein.
For the most part, I agree that the book is well-written and fairly comprehensive, but I think it contains a few errors that should be corrected.
Note also that there are almost certainly differences between Euro and NA market cams, and unfortunately Croft has published no listing of these- whether he has them jotted down somewhere in secret, I have no idea.
Also, I believe you were referring to a supercharged motor, which has obviously different requirements than the N/A versions detailed in the "case histories".
Croft's book lists a Beta ie inlet cam and Std. exhaust cam as a suitable combination for fast road use, and a "GC3A" inlet and Beta exhaust cam for race use.
Note that, at least over here on this side of the pond, three of these four cams are IDENTICAL down to a thousandth of an inch or two, and a degree or so. From the data on page 80, we see these "GC3A" are assymetrical cams, they are some proprietary grind of his, so I won't venture to comment on that, but I'd be a little pissed off if I spent a bunch of time and money hunting down some cams I didn't have, and found them to be identical to the ones I already had!
There are two supercharged engines that I recall seeing in the book, one is the one in a Hawk that was estimated at 180HP. Since it says "estimated", I can only assume it wasn't dynoed, and from that I can conclude only that GC was making an educated guess as to what the optimum cam combination would be. The other supercharged motor was built by Tom McGaffigan, He's on one of these lists, I think Lanciascorpion on yahoo groups or perhaps even this one, his engine was quoted as putting out 175HP. That one may have been dynoed- and you may want to talk to Tom about it.
Nathan Dalhammer Vx'ed a Scorpion using a 40/80 and a stock Vx exhaust cam (I haven't measured this cam, as I have it IN a motor at the moment) but it just MIGHT be a better combination.
Anyway, apologize if I was out of line, I meant to suggest that you might want to find out specifically what you are dealing with, rather than take it on the advice of somebody who is the go-to guy (Guy) based on a book which is primarily about normally aspirated TC engines. Will his guess be better than yours (or mine)? Quite possibly- the guy made a living for a bunch of years doing performance tuning on TC's. But, if you treat someone, no matter how experienced, as infallible, and never bother to check for yourself, lots of times you end up getting the short end of the stick.
I don't know what Guy's been doing since he wrote that book (it was a few years back, before I ever SAW a Lancia TC), he may have built and tested several volumexes since then, but there's not enough Volumexes in that book to make me comfortable with taking a cam combination on faith.
I willingly admit that my perhaps inappropriate response earlier, which may have been unfair to Guy, stems from the fact that I am still miffed over the fact the maligned me previously, and refuses to make available either an addendum to his book correcting several issues, or data that could help the community enormously. believe me- I HAVE tried contacting him, and getting his cooperation.
You don't have to wait for my "weighty tome" (good one), I'm adding things into the FIAT_TC_Motors group as I get them ready, and hey, it's also FREE FOR EVERYBODY-JUST LIKE THIS SITE.
I think It'd be damn nice to have a comprehensive library of information available. -Will

[Will]

Forgot to mention:
I would REALLY like to get cam grind tables from FIAT!!!!!
If anybody knows how to acquire these, I would find a way to repay your kindness!
-WIll

[Hamish]

:roll: Will,
I see what you're saying and I confess to my ignorance :oops: in the finer topics of engine tuning/engineering. I appreciate there are likely to be substantial differences between European and NA spec engines - especially those with smog gear fitted, don't fancy that at all!!
I've had my fair share of hassles trying to get info out of Guy - however he is the most respected tuner of the Fiat/Lancia twincam that I know of. I do know that the 130 tc has more duration on the inlet (and therefore more lift?) I'm no expert but I do understand that fitting a cam which will help the engine breathe better is good - all it needs now is some nice 44mm inlet valves, a better/different inlet cam and a nice sidedraught 45 bolted to the blower and ..... well, the list goes on and on :mrgreen: . It's mostly wishful thinking as I do use the car daily; and it's just gone 'bang' :cry: so my good lady wife is limiting my spending on the engine :( (spoilsport!) .
I've spoken to one guy who has fitted the overdrive pulley in conjunction with a 40DCNF on a standard manifold and a Beta IE inlet cam, he reckons it puts out about 170BHP - I'd like something in that territory as I keep getting blown away by new turbodiesels!! It has also been suggested to me that ditching the standard manifold is agood idea, and when you consider how far the fuel travels on a standard VX before it reaches the blower it seems like a good idea to me :wink: .
I have looked at the Yahoo site you mentioned and signed on to it, I see where your 'weighty tome' is being distributed and it's refreshing to see someone going to all that trouble for nothing - not something I'd normally associate with the mechanical world (absolutely no offence meant to anyone by that comment!! :lol: ) good for you!. For info, Guy sold up his business to MRH (basicaly the rest of what had been GCT) and went off to work with Brian Hart (used to make Formula One engines - I think he still makes endurance engines for the American Le mans series and for hill climbers etc etc) and recently decided to start up again doing Fiat group engines including the SOHC types.
I'll say one thing for Guy - he knows how to charge!! His pricelist compels me to learn how I can do a LOT more at home.
So all I have to do now is rebuild an engine for my VX, do the garden, paint the house (inside and out ofcourse) build a fence and then try and find some time to go fishing. Oh! and find some time for the wife. Joy. :roll:

[Will]

Hamish:
Duration and lift are two seperate and distinct factors, cams with the same lift can have greater or lesser duration, depending on the shape of the lobe, likewise, cams of the same duration can have more or less lift.
More LIFT in the same duration is good, unfortunately there is a practical limit to this because too much valve acceleration leads to other problems, like valve float at high revs (valve float can hurt your engine BADLY!)
Greater duration sounds good in theory, the problem is that if duration is increased, unless lift is reduced, overlap is also increased. Look at the graphs and you'll see how this works. This means a reduction in torque, particularly at lower RPM. You can try to compensate for this by fiddling with the timing, but everything is a delicate compromise, a tradeoff for power in the high band vs. torque in the low band.
Your volumex makes power lower, and can't rev as high as a normally aspirated motor, so you should take that into consideration and stay away from long duration cams, PARTICULARLY the exhaust cam.
The longer the exhaust cam duration, the greater the overlap, crippling the intake at the pont where the intake charge is just overcoming its inertia and beginning to move into the chamber. I would look into an inlet cam change possibly, and keep the stock VX exhaust. But that's just me, everybody's entitled to an opinion.
Certainly fitting a DCOE to your volumex will help tremendously, and EFI is even better. A mapped EFI with ignition combo may allow the safe use of standard compression pistons on the volumex as well, I plan to test this on the volumetrico when I finally get it taken apart and put back together.
I figure Croft is entitled to charge what he wants, he'll undoubtedly be constrained to what the market will bear. The book was certainly good publicity and marketing, I'm not so sure any one of a half dozen other places couldn't to comparable work at a lesser cost, but if he can find people willing to pay top dollar, more power to him.
I'm not rushing to give him $10 for a classified ad on his site though, when I can put my stuff on viva-lancia (or here)for free, and it doesn't look like others are, either. It's been my experience that the FIAT/Lancia crowd are pretty frugal, so I suspect some of his pricing may be negotiable.
Stateside, we have PBS, Apple, Shadetree,Serra, etc.
-Will

[Hamish]

:roll: It's been pointed out to me that I've made an error in a previous message: I had suggested that I'd had trouble getting info out of Guy Croft.
I should like to make it crystal clear to all who use the forum that this is not the case. Guy has been very helpful on a number of occasions when I've approached him for help, something which other companies could do well to take heed of and learn from.
My 'difficulties' in the past were with MRH (the crew who bought out GCT); just goes to show how not reading your messages before posting them is a bad idea!
Apologies to Guy, no offence intended! :oops:
Hamish

[Duncan]

I suspect I'm being stupid, but is there any chance of a URL for that TC site? I've done a couple of websearches with no luck, and I'd be interested in reading whatever info is there...
Cheers
Duncan

[Gary Severson]

It is in Yahoo Groups.
http://groups.yahoo.com/group/FIAT_TC_Motors?yguid=27128122

[Be-All VX]

Nathan had G-Teched my car and his results were 150 hp and 150 ft-lbs of torque at the rear wheel. Im not sure how accurate the G-Techs are, but comparing the car to other vehicles I've had, the seat of pants estimate is arround 175 to 180 hp at the flywheel (compared to my Porsche 911). With the cams Nathan selected, this car runs smoothly, pulls hard all the way to redline. The torque curve is very proportionate, no power band effect. It is a pleasure to drive, and will smoke a lot of cars who start to get froggy! I am considering an engine management system, because it is currently running a Saab turbo EFI, so I figure if I could tune the fuel/air mapping this car would be even more increadible than it is now. Any ideas or suggestions? :twisted:

[Duncan]

Thanks Gary :lol: I've now joined.
Cheers
Duncan