ALFAGTV6.COM

True, we have all been watching the sinking ship called Greece here.... They are hacking everything regarding pay and increasing all taxes as usual, a recipe for more austerity. My bad choice of country, not that I had much say...
On the 24v front, I did some detail work on the valves and valve seats as I thought there was room for a little improvement. Therefore I will measure flow again this week and report. At this stage, I am convinced one should do their own seatwork for best results. Regrettably, different machine shops do them in different ways and if you know your stuff, you dislike most of their work! Buying my own quality cutter set (Neway) is expensive and not an option now -should have bought them 4-5 years ago. As a point of interest here, I have seen the best seats on std Alfa 33 16v heads; true radius seats! Anyway, stay tuned for more news from the bankrupt dump, later!
Jim K.

I feel I should head over to Greece and have you teach me how to cut valve seats. Maybe in 1-2 years? I'll bring over a few neways

Wow just checked, it won't cost anything less than $1K.


BTW what's a radius cut? Is it a 3-angle (30-45-60) cut and then blended ?

Radius seat is just that, round cross-section no flats, except for the necessary valve/seat contact patch, 0.8mm intake/1.5-2mm exhaust. Difficult to make unless you have a specially made cutter tool. I regret not buying Neways little by little. I would have a fairly good set by now over 5-6 years.
Jim K.

Not very inspiring to work in 32-36*C outside temps but this dinosaur has to finish sometime! Today I lapped valves/seats, installed seals, springs etc. Maybe I can bolt the heads on in the next few days... After lapping, I always check for a perfect seal by holding the valves shut with fingers alone, with head tilted sideways and pouring cleaners gasoline in the ports. If it doesn't leak at all for 4-5 seconds, I çall it good. Many machine shops claim you don't need to lap after their seat forming machines do their part but I wouldn't think of it. Others say 'don't bother, a good seal will result after a very short working time'... bull! Make sure its good when you can and that's it!
Jim K.

Ok, wading along happily with a little breeze... Bolted the heads on today and put followers/cams on. I'm using the least amount of oil since I hate the stuff running around; barely enough to prevent scuffing at this initial assembly stage. I will pour on a lot more before finally closing valve covers. The variable pulleys look ok and I am contemplating to zero them at 110* lobe centers. These will be determined accurately with the degreed pulley and dial indicators on the followers after the belt is tight.
Since the damn wasps are buzzing around always looking for a nest, this time I have all engine holes plugged... don't want/can't afford a repeat performance like last year!
Jim K.

Hey nothing wrong adding a little bit of sting to your engine

My 156 3.0 will have its cams adjusted tomorrow per your spec. Next year it will get shaved and cl cleaned heads and a remap.

In the above pictures you have the ferrea racing valves pictured.. well at least in the box.

I thought earlier in a post you said they didnt perform as well as the standard valves

I did i mis-interrupt a post.. anyway looking good. how long before it reaches a dyno

and are these your own cams as available on the forum or a special spec for this build

An eye for detail... Yes, I worked a little back-cutting the valves on the valve grinder smoothing the seat/tulip transition. Back to the flowbench and thank God, the money was not paid in vain! The cams are the same 10.3mm we have talked about. The most important job left now is the plenum. Two solutions will be tried, the short 75V6 (currently on my 3liter 24v) and an enlarged gta plenum with relocated throttle body. I want to verify simulator results.
Jim K.

Are you only trying single plenum set ups on this engine.

best results are with twin plenum set ups from what i can gather though no relevant data to prove this as yet.

Hopefully a modified GTA plenum with a larger capacity and 70mm throttle body will prove nearly as good.

As it will be much easier to fit in most vehicles.

Looking good Jim , from my side on subject of plennum and from my mates in SA the bigger throttle body made no difference apart being difficult to map at low rpm even on the 3.7 motors so I doubt it will be any better on the 3.2 .
The tapered plennum on side delivered really good power on number of 24v motors we raced and was the easiest to build . It might not look the prettiest but we sure hit our hp figures we were looking for even with our short exhaust headers which are no where near as efficient as your stuff . I also cut the metal part of the side plennum that goes over the coils on the race motors to eliminate heat soak but not ideal on every day road car with a vented bonnet as moisture crept in .
At least if you go side plennum your hp figures can be more identifiable with the guys having 24v motors in the FWD Alfas .
Side plenum with taper in referring to is in below pic .

Thanks Kevin, that's what I had in mind to build after seeing so many similar jobs, except the hole in the body work which is not necessary in my case. I am also contemplating making a single 6xthrottle body, thin ~20-25mm to superimpose between plenum exit and rubber pipe connectors. It will actually bolt flat on plenum exit and the 6 plenum exit throats will be attached to TB backside. I have to think it some more though...
There's a guy in France who used 2 std throttle bodies side by side on a similar plenum as your pic and got much more power/torque... Must find it and read it again...
Jim K.

I think the Scuderia Del Quadrifoglio guys are here. Yannick is one of them:

http://alfaromeosportclub.forumactif.co ... adrifoglio

yeah i was thinking along the lines of using two standard plenums each feeding a different bank.

something like the Ferrari set up ..lol

70mm throttle body is what my maths comes up with as ideal on the 3.8 litre with either 2 2.5 litre manifolds or one at 4.560 litres..

Hey Jim, due to a change in circumstance, I'll be following your build with interest- I just put a deposit down on a 147 GTA engine myself

Have you considered using something similar to the Clio Williams profile cams you discussed in your V6 book?

I haven't dealt with throttle size yet, but from what you say the std 72mm seems to be fine, right? I'll read up on the French post and learn some more.
The Renault profiles are available from the grinder, but I think my 10mm profiles are much better; they have worked well for some people. The 10.3 hasn't been tried yet, it'll make its first appearance in my engine.
Jim K.