| View previous topic :: View next topic |
| Author |
Message |
phoskam
Snailer
Joined: 30 Oct 2007
Posts: 19
Location: Rossum, Netherlands
|
 Posted: Mon Dec 15, 2008 1:15 pm Post subject: custom made pistons for visa |
 |
|
hello everybody,
For my visa engine i am looking for some other lighter pistons, is there anybody who has some experience on this subject ?
I am building a tuned visa engine for my 2cv.
' fast ' camshaft, lightened flywheel, 123 evo ignition, weber 40 DCOE carburettor, and because of the higher engine revs a pair of light pistons would af nice.
Every information is welcome.
( I will start a topic about my whole project in a few days..) |
|
| Back to top |
|
 |
Harley
Dropped
Joined: 26 Nov 2007
Posts: 394
Location: Braidwood - Australia
|
| Posted: Mon Dec 15, 2008 7:59 pm Post subject: |
|
|
Hey Phoskam,
It was an easy choice for me, there is only one place close who machines forged pistons and thats all they do! I just took a piston to them and told them what they where from, compression ratio etc.
Some 'improvments' they made:
Narrowed gudgen pin = less material = lighter
Rings moved further up
Rings also improved, noticably thinner...
grove cut under top ring = improved cooling
Flat head = improved combustion (they where able to recreate the 'volcano' top face but recommended a flat top)
Alloy material = better heat transfer cooler operating temps
You shold also consider the compression ratio, as it is easy for them to make it to suit... 8.5:1 forced induction or maybe 9.5:1 naturally aspirated.
Cost was just under €400.00  does that out weigh the gains 
Andre PP lists them for €650.00...
I haven't compared the weight of the pistons but it dosen't feel much lighter...
Hope thats usefull
Harley
_________________
Check out my Dinosaur www.youtube.com/watch?v=RPF_uU61als
Spot my 2cv  www.youtube.com/watch?v=Zoq68CPLq4M |
|
| Back to top |
|
|
backfire
Dropped
Joined: 14 Nov 2007
Posts: 346
Location: NL, 's-Hertogenbosch
|
| Posted: Mon Dec 15, 2008 8:48 pm Post subject: |
|
|
Hi Harley, do they also have the matching piston rings to be used with nikasil cylinder?
_________________
2CV, with Visa turbo charged |
|
| Back to top |
|
|
Harley
Dropped
Joined: 26 Nov 2007
Posts: 394
Location: Braidwood - Australia
|
| Posted: Tue Dec 16, 2008 6:11 am Post subject: |
|
|
| backfire wrote: | | do they also have the matching piston rings to be used with nikasil cylinder? |
Yes, supplied with Wiseco rings for use with Nikasil cylinders...
I should also mention that i had my barrels inspected at Electrosil and had them honed. I then took the barrels to the piston maker to have them mesured accurately...
Harley
_________________
Check out my Dinosaur www.youtube.com/watch?v=RPF_uU61als
Spot my 2cv www.youtube.com/watch?v=Zoq68CPLq4M |
|
| Back to top |
|
|
phoskam
Snailer
Joined: 30 Oct 2007
Posts: 19
Location: Rossum, Netherlands
|
| Posted: Tue Dec 16, 2008 12:16 pm Post subject: |
|
|
it's a pitty australia is so far away  |
|
| Back to top |
|
|
phoskam
Snailer
Joined: 30 Oct 2007
Posts: 19
Location: Rossum, Netherlands
|
| Posted: Tue Dec 16, 2008 3:30 pm Post subject: |
|
|
harley, can you measure the weight of one of your new pistons ?
And maybe also the piston pin, or is that gudgen pin, weight ?
That would be nice. |
|
| Back to top |
|
|
backfire
Dropped
Joined: 14 Nov 2007
Posts: 346
Location: NL, 's-Hertogenbosch
|
| Posted: Tue Dec 16, 2008 7:39 pm Post subject: |
|
|
Or better weigh them together the piston and the pen guideon? If al is right difference in weight between left and right piston should be minimal.
_________________
2CV, with Visa turbo charged |
|
| Back to top |
|
|
phoskam
Snailer
Joined: 30 Oct 2007
Posts: 19
Location: Rossum, Netherlands
|
| Posted: Tue Dec 16, 2008 7:44 pm Post subject: |
|
|
You are right about that Ron, but I'm also curious about the difference between original visa and custom piston.
(grappig eigenlijk, wonen we 15 km van elkaar en zitten we via een engels forum te communiceren  ) |
|
| Back to top |
|
|
Harley
Dropped
Joined: 26 Nov 2007
Posts: 394
Location: Braidwood - Australia
|
| Posted: Fri Dec 19, 2008 11:23 am Post subject: |
|
|
I have weighed the Pistons:
Standard Visa piston 9:1 = 460g w/ gudgen pin
Custon piston 9:1 = 400g w/ gudgen pin
Difference of 60g = not much!
Standard gudgen pin = 95g
Custon gudgen pin = 85g
very little difference in weight...
Harley
_________________
Check out my Dinosaur www.youtube.com/watch?v=RPF_uU61als
Spot my 2cv www.youtube.com/watch?v=Zoq68CPLq4M |
|
| Back to top |
|
|
backfire
Dropped
Joined: 14 Nov 2007
Posts: 346
Location: NL, 's-Hertogenbosch
|
| Posted: Fri Dec 19, 2008 9:40 pm Post subject: |
|
|
not much??? Total difference is 60 gram on total of 460 Gram, thats more then 13% weight los. Do you know what difference this makes on top RPM? You know that weight op pistons are more important than the weight of your flywheel.
please remember that it is almost 1/2 KG per cilinder.
PS If I am not mistaken 2cv6 piston weighs about 70 gram less then Visa piston.
_________________
2CV, with Visa turbo charged |
|
| Back to top |
|
|
dyanut
Dropped
Joined: 05 Aug 2007
Posts: 177
Location: North Yorkshire
|
| Posted: Sat Dec 20, 2008 12:30 am Post subject: |
|
|
Not mistaken, since a 9.0:1 piston with gudgeon pin weighs 390g... 
Ken.
| backfire wrote: |
PS If I am not mistaken 2cv6 piston weighs about 70 gram less then Visa piston. |
|
|
| Back to top |
|
|
Harley
Dropped
Joined: 26 Nov 2007
Posts: 394
Location: Braidwood - Australia
|
| Posted: Sat Dec 20, 2008 6:37 am Post subject: |
|
|
| backfire wrote: | not much??? Total difference is 60 gram on total of 460 Gram, thats more then 13% weight los. Do you know what difference this makes on top RPM? You know that weight op pistons are more important than the weight of your flywheel.
please remember that it is almost 1/2 KG per cilinder.
|
Ok it would seem a resonable reduction, i had expected 100+ difference. This is my first experience with engine tuning so it is all comparative to what i have read...
Anyone know how to calculate the rpm gain vs piston weight? i will have a look through my books.
Harley
_________________
Check out my Dinosaur www.youtube.com/watch?v=RPF_uU61als
Spot my 2cv www.youtube.com/watch?v=Zoq68CPLq4M |
|
| Back to top |
|
|
jan-jacob
Snailer
Joined: 26 Sep 2008
Posts: 5
Location: Kudelstaart Holland
|
| Posted: Sat Dec 20, 2008 10:21 pm Post subject: |
|
|
We are working on new pistons for the Visa engine (77mm pistons). We hope that we have in Januari the first prototype's for testing.
Jan-Jacob Straathof
www.autobouwservice.nl |
|
| Back to top |
|
|
phoskam
Snailer
Joined: 30 Oct 2007
Posts: 19
Location: Rossum, Netherlands
|
| Posted: Sun Dec 21, 2008 5:26 pm Post subject: |
|
|
Hello jan-jacob,
that sounds nice, I'd like to hear the outcome. |
|
| Back to top |
|
|
björn
Lowered
Joined: 19 Jun 2007
Posts: 1695
Location: hillywood(hilversum)/holland
|
| Posted: Sun Dec 21, 2008 10:34 pm Post subject: |
|
|
me twee (two)
_________________
 |
|
| Back to top |
|
|
|
FAQ
Search
Memberlist
Usergroups
Register
Profile
Log in to check your private messages
Log in
