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Fundering squish zone och CR B234f low budget

Postat: ons jan 25, 2017 12:17 pm
av Hempp2_
Hello
You can answer with swenska, I can understand it, but the writing takes a eternity...

I sold my old 8 valve turbo engine as a packet, so my 244 needs new engine. I have b234 head and misc. I have in my mind getting b230FB bottom with oilsquirters. I'll swap my spare H-profiles and bore the oil return to block.

I have to mill the valve reliefs to pistons, but I allso thought that I could mill the head of the piston flat to get lower the CR...

Will this ruin the squish zone effect and does it matter on 16v valve setups?

I calculated the differences in CR
b230f original as a test
bore 96mm
stroke 80mm
hq 99mm/1mm (id/thickness)
Combustion Chamber Volume 53.7cc
Enter Piston Dome Volume In CC -7.23cc (64,7x2.2mm)
Enter Piston Deck Clearance -0.4mm

CR=> 9.8


B234f head + b230fb bottom (didn't calcultated the size of valve reliefs)

bore 96mm
stroke 80mm
hq 99mm/1mm (id/thickness)
Combustion Chamber Volume 48.5cc
Enter Piston Dome Volume In CC -7.23cc (64,7x2.2mm)
Enter Piston Deck Clearance -0.4mm

CR=> 10.5

B234f head + b230fb pistons milled flat (didn't calcultated the size of valve reliefs)

bore 96mm
stroke 80mm
hq 99mm/1mm (id/thickness)
Combustion Chamber Volume 48.5cc
Enter Piston Dome Volume In CC -15.924cc (96x2.2mm)
Enter Piston Deck Clearance -0.4mm (The real clearence of the piston to head is 1mm-0.4mm+2.2mm=2.8mm)

CR=> 9.35

My choise would be the last one, if the milling the wount ruin the charagesteristics of the swirl on the combustionchamber

I drive with e85, but somehow I prefer little lower cr and higher boost pressures. Have tried to map 1:10 cr engines, but there is allways a little fear to dial the boost up and give larger spark advances to gain torguen and power...

Re: Fundering squish zone och CR B234f low budget

Postat: tor jan 26, 2017 9:07 pm
av Pacman
Min första tanke är B230FK/FT kolvar med frästa ventilurtag. Är det svårt att få tag i sådana där du bor?

Re: Fundering squish zone och CR B234f low budget

Postat: mån feb 20, 2017 9:35 am
av Hempp2_
I found FT pistons, I planned using the FB pistons because I did't have any turbo pistons strored for this project...