ALFAGTV6.COM

kterkkila · Post by **kterkkila** » Tue Jan 17, 2006 2:37 am

MD wrote: I guess you'll just have to suck it and see .

That's the plan

MD wrote: I do agree with other comments that you may need to better integrate the two components and balance it as a unit before mounting onto the crank. I think it would be a safer and better option with better balancing outcomes.

All pieces are going to be balanced separately to allow mixing components in future. Mean that the crank will be balanced first alone, then with front pulley, then add flywheel (starter gear holder) and balance again, and lastly add the center triangle to complete the assemply and balance once again.

I don't see reason for fixing those two parts together as they will center to each other and the position will be marked?

Maurizio · Post by **Maurizio** » Tue Jan 17, 2006 4:07 am

I don't see reason for fixing those two parts together as they will center to each other and the position will be marked?

I have in other than engine parts and 8000 rpm some very bad experiences . Even with very small tolerances you get an inbalance very fast . (cantilever effect: small positioning hole and a large diameter flywheel). The best way: is balancing assembled and leave the parts as they are mounted. But that will only work in a perfect world

ps the crank of my ts engine is lightened. Had a sketch from a forum member and did my own interpretation

Only will take a long time before I can share experiences. The progress on the engine is very slow......

Micke · Post by **Micke** » Sun Apr 16, 2006 1:53 pm

Now I'd need some help.

I've been "building", or actually collecting parts and inspiration, for my TS for some time now. Some 10 years ago I bought stiffer valve springs for the old 2.0 and today cleaning my junk finally found them

The springs are very strange with 3 springs of which one between the normal inner and outer is "standing on the side". Anybody know these and have any idea if they are any good?

Then if Jim or someone has the critical measures i could check whether they fit my project. What's the needed stiffness and max compressed length with 13 mm cams? What's the open lenght mounted in the engine.

Sorry, some questions might sound dumb, but my engine isn't here and I'm realy curious if these will do.

Mats · Post by **Mats** » Sun Apr 16, 2006 2:59 pm

The one that goes in between is really only there as a damper as I understand it, are the springs wound the same direction (as in right or left?) otherwise it can be to keep the springs from coming tangled in some weird accident...

Jim will probably have the exact answer though.

Micke · Post by **Micke** » Sun Apr 16, 2006 11:11 pm

That's what I figured as well. Keeping the resonances away. However, I tried and they do flex like springs. Never had any of these before so I'd like to know more.

Maurizio · Post by **Maurizio** » Sun Apr 16, 2006 11:48 pm

Micke, picture?

Micke · Post by **Micke** » Mon Apr 17, 2006 2:26 am

A picture of ME?

Oh, I'm flattered. I know I'm handsome but that's a bit exxaggerated

Here's one of the valve springs instead.

Notice, the inner spring is a lot shorter than the outer one. Not knowing the measures I wonder if the inner one is unloaded when the valve is closed. This would reduce seat pressure. The "thing" between the springs would keep it from rattling.

Open length of the springs:
Outer 49.2 mm
Inner 38.5 mm

la_strega_nera · Post by **la_strega_nera** » Mon Apr 17, 2006 4:50 am

You'll find that at installed height all 3 springs are compressed to some extend.
The middle coil is a damper, its a push fit against the inner and outer coils and will dampen harmonics through friction. This is a Standard High performance valve spring design.
On the agricultural V8s we remove the inner and the damper for Cam break in, especially with stiff springs and agressive cam profiles, it helps prevent the lifters and lobes eating each other untill its all bedded in (Hold 2000-3000rpm for 30 minutes, you can shut it down inbetween if it gets too hot, then let it cool and re-fit the inner and dampers. pain in the ass of a job, but necessary when the lift rates are approaching the lifter edges....)

Mats · Post by **Mats** » Mon Apr 17, 2006 8:19 am

There is a step in the retainer so the inner spring is loaded as well, the step also keeps the outer spring centered.
The springs are wound the same way, not too clever.

Micke · Post by **Micke** » Mon Apr 17, 2006 9:18 am

I think the springs must be wound like this not to foul up with the middle thingy which goes the other way.

Jim K · Post by **Jim K** » Mon Apr 17, 2006 11:01 am

DON'T USE THE DAMPER COIL. I don't know what they do in the US, but for AR engines the triple setup is exceptionally nonlinear and more than 210lbs at 10mm lift (way too much)! I've used these sets over and over again without the dampers, in same and opposite wind coils, no problems ever. For high perf use, aim for seat pressures of 85-90lbs and 185-190lbs at 10mm lift. These measuremants are made using the std AR retainer (most retainers have a 2mm step for the inner spring) Make sure your installed height allows max valve lift plus 1-2mm at least before coil bind.If you want the whole curve just say so and I'll post the numbers, or (for a schnitzel) the graph!

Jim K.

Post by **Zamani** » Mon Apr 17, 2006 12:20 pm

Here you go JimGreek

Jim K · Post by **Jim K** » Mon Apr 17, 2006 12:51 pm

Slurp,droool!! Rats, I'm licking the screen here!!

Ok, I is a man'o me word but its almost midnight now, will post the graphs tomorrow (std AR springs and hi-perf ones from Arricambi) What do you want, 4 or 6cyl?? (they're different)
Hey Z, got some ice-cream for dessert?

Jim K.

Micke · Post by **Micke** » Mon Apr 17, 2006 10:09 pm

4 cyl OF COURSE!

Jim K · Post by **Jim K** » Tue Apr 18, 2006 11:48 am

Better late than never! The damn Camedia kept shutting down on me...gotta get ACDSee again.
Anyway, I found the graph for the Arricambi (Shankle) 4cyl springs, but not the std ones. Don't worry, I got the stock numbers and they were exactly where the Shankle catalog said: seat pressure with installed height 35.5mm = 80lbs and pressure at 10mm lift (ie 25.5mm height) = 160lbs. Very important for high lift cams is the coil-bind height which for the performance springs is 20.5mm, in other words you can have up to 13mm safe valve lift!!
Don't bother with the two curves under the final one. They are the inner and outer spring graphs. They will NOT add up to the higher curve, as the inner spring is compressed 2mm by the retainer.
If you have lightweight valves you will logically need a value in between std and high perf, but it all depends on your max revs and cam design (specifically the acceleration features of the lobe)
Sorry for the quality guys, it is readable if you're determined enough!
Jim K.