ALFAGTV6.COM

[Jim K]

Hell NO!! I saw it when I got them and I remember it cost a lot too! They said it works, so in the interest of...science I'm willing to give it a try. I share the concerns about the chamber getting too hot leading to all kinds of trouble, but thermodynamically speaking, we want a hot chamber! Just how hot...nobody knows! I guess we'll find out soon enough.
Jim K.

[j.k.QV]

I think Mats complained about the non-EVO manifolds (cracking? and not so good design?). But have not heard him blowing a HG (consider that I have VERY limited knowledge on this engine here).

But it would be nice to have a 2.0 TS Turbo in the engine bay.

JK, what do you think? 2.0 TS T? More trouble than it's worth??

What about 2.0 Nord with 9:1 static compression + a snail?

I know it's not the right thread, but what the hell.
Here is a video of 2.0TS turbo on a dyno.
http://www.youtube.com/watch?v=4c1nVh8xTJ0

Looks quite interesting

[slyalfa]

Any news on this??
can we get them yet?
I checked spruellmotorsport and I do not see anything for a v6.
are they a over size so we can bore/hone used liners?

[Jim K]

Well, the engine has ~500km now, and I'm shifting at 5k. I opted for the 'aggressive' way of break-in, stomping it from about 3.5k-4k initially and up to 5k from ~400km. Hard acceleration followed by off-pedal deceleration to 3.5k and so on mostly in 4th/5th gear.
CR is 11.4:1 and with the fast road Catcams (P/N 1030321) hot compression is 220psi all around. The big-bore headers are on and I'm using the map from the previous V6.
Inital observations: the pistons make a lot of noise when cold which all goes away after a few minutes. Although these cams are mild, idle is lumpy at 750-800rpm but evens out at about 950-1000rpm. The pistons are not oversize, I used them with new liners. They are not listed by JE but if you ask P.Spruell for 'Jim's pistons' I'm sure he can get them for you, although they cost a lot more than their standard V6 pistons -which aren't noisy either!
I'll map/dyno at ~2500+ km, at which point I will be able to assess performance. No more to say, nothing interesting so far. I'm spending more and more time with the two 1.8T turbos...
Jim K.

[Zamani]

JK,

The flat top spruell 10.5:1 pistons you used before didn't make noise right? Mine doesn't. I'm assuming JE used the same low expansion material for your new non-full skirt pistons. So would you say the noise is due to the non-full skirts?

Also, do these pistons bring compression up to 11.4 with stock heads or do the heads need to be shave to have the compression up that high?

[Jim K]

Right, the previous pistons never made noise. I assume the special alloy used this time and the very small skirts are responsible for the noise. Noise means wear in my book, but people using similar pistons don't expect 200,000km from their engines!
The pistons were 10.5:1 with std heads, so I milled the heads for the planned 11.4:1. Fortunately, this piston design allows Godzilla cams to be used.
A little side story here from the build/startup: the Motronic crank sensor is mounted on two bosses in the timing cover. All Jetronic 3liter timing covers and many 2.5 ones had these bosses in place, though undrilled. One would assume the bosses being in the same spot in all versions. Well, when time came to put the sensor on, I just took it off from the old engine and bolted it in the new one before stuffing the engine in the car. When it first fired up, it wouldn't idle properly, so we cracked open the butterfly a bit more. Running it up to 2krpm in the garage and checking for leaks etc, the headers turned bright orange....!! WTF? Anyway, I drove the car home using the highway and noticed no power at all; I figured the engine is tight, what the hell! Temperature was normal and so was oil pressure. It all felt wrong though and when I got home I started checking around...I have a few timing covers laying around and by pure chance I noticed something was different here…Sure enough the sensor bosses were in different locations! Turned out that in the new engine timing was retarded by a whole 17⁰ !! The glowing headers were waving at me but I just didn’t get it at the time. My only possible fix was to fabricate an offset sensor bracket and I must say I did a great job of it as it fell smack where it should be, shifting sensor position by the required 17⁰. With this opportunity, I checked the 24v timing cover and sure enough the mount is elsewhere…What can I say, it was an interesting experience!
Another snag, this time with the Catcams….put them in and timed the engine (or so I thought). Upon trying to check for valve/piston clearance with the help of dial indicators and the degreed crank pulley, I was getting some very strange numbers…checked and double checked until I found the cam timing notches on both cams to be 16⁰ away from where they should be…! Makes me think I may be the only one ever to buy these cams?? Other than this, the cams have very modern high acceleration profiles and maybe this feature alone can be responsible for the lumpy idle.
For the time being, the Halmeter says I’m running ok, but the wbo2 says I’m hopelessly lean…I suspect an air leak downstream of the Halmeter and before the wbo2. Will have to check.
Oh well, enough for now, I’ll be back when I got something interesting like dyno figures.
Jim K.

[Maurizio]

Jim, heard a similar story:
an V6 S-cam copy delivered by Catcams, timing mark also completely off... so they are consistent..


Saluti,
M

[ChrisS]

I learned my lesson with timing marks on my last-but-one build. Cams were fine as it turned out, but the scribe mark applied at the factory (he says kindly, dent made with a chisel more like) was wrong on one head. A whole tooth out.

Not that I do many of them, but fresh builds will always be dialled in with old-school methods from now on, then I use the 164 timing template to take a reference figure for the given engine so I can do quick and dirty cambelt swaps in future if I have to.

Engine I recently built, using some RJR cams, dialled in as per the sheet, marks came up very close to ideal on the template once I was done. Can't recall the exact number now, but very close to nominal Alfa spec. Don't consider that means very much as such, just an observation. RJ is most vehement about not using marks or templates. Given the sensitivity of cam timing, I couldn't agree more (now!).

Apropos forged pistons, Greg warned me to expect some noise when cold from the set of LC Venolias he supplied me. A bit, but not bad. Soon goes once it's warmed a wee bit.

[Zamani]

yes about the cams (off topic a little here), I'm sure you too spent some time with RJ to discuss specs. He and I mulled over lobe centers for a while. And the difference was just 8 degrees (between what he says would pass emissions easily and what would make it more difficult). So imagine if one just relied on the factory marks, One is basically forfeiting the effort put into the details as the marks may be off by more than the 8 degrees on LC one was mulling over.

Anyway, I'm going to re-adjust the cams again soon.

[kterkkila]

Is there any pin offset on those small skirt pistons? If there isn't and full skirt ones does, then it could be the main reason.

[kterkkila]

Now I bothered to read some old posts. Yes, it's mentioned that those were with centered pins..

[slyalfa]

I thinking I might want the older type. As I push it a little too hard some times before it is as warm as it should. And a flopping piston just seem like it would be extra bad in that case. That is if I can get any one to sell them to me....

If I bore a old liner I think the cost will not be too much more then a set of stock with liners.

[Jim K]

These new pistons cost a lot more than the 'old' JE forged ones; the only reason I had them made is I wanted the particular dome shape. Unfortunately, we somehow got our wires crossed and I didn't get the full skirt I was after.
I wouldn't advise boring liners unless you have a certified competent shop that can do it and end up with a ROUND AND CYLINDRICAL bore....I have measured many attempts to enlarge liners and while they are all usable, ovality and taper specs are a joke. Even new std Alfa liners have ovality, sometimes OUT of published spec -and don't tell me it will disappear when clamped down because it doesn't!
Jim K.

[Duk]

These new pistons cost a lot more than the 'old' JE forged ones; the only reason I had them made is I wanted the particular dome shape. Unfortunately, we somehow got our wires crossed and I didn't get the full skirt I was after.
I wouldn't advise boring liners unless you have a certified competent shop that can do it and end up with a ROUND AND CYLINDRICAL bore....I have measured many attempts to enlarge liners and while they are all usable, ovality and taper specs are a joke. Even new std Alfa liners have ovality, sometimes OUT of published spec -and don't tell me it will disappear when clamped down because it doesn't!
Jim K.

Ovality as a result of clamping the liners in a lathe chuck perhaps?
Boring bar flex?

How about having a torque plate fitted to the block and boring and honing to size with the liners still in the block (olde school )?

[Jim K]

Alfa liners are usually bored clamped on a boring machine; I haven't seen them bored in the block. If someone does this as proposed and the resulting measurements are as they should be, I'm all for it!
Jim K.