Group 21 Reconditioning engine
Specifications
DEMOLIN
PISTONS(B27)B27A
1976-1979
B27E1975-1978
B27F 19791976-1978
Height,overall74mm(2.9134in)63.4mm(2.9960in)
fromgudgeonpincentretopistoncrown40mm(1.5748in)39.4mm(1.5512in)
Weight445±3gram
Maxweightdifferencebetweenpistonsinsameengine6 gram
Pistonfloat
0.090-0.110
mm(0.0035-0.0043in)
Pistondiameter,A-markedpistons
87.900-87.910
mm
(3.4606-3.4610
in)
B-markedpistons
87.910-87.920
mm
(3.4610-3.4614
in)
C-markedpistons
87.920-87.930
mm
(3.4614-3.4618
in)
Pistondiameterismeasuredatrightanglestogudgeonpin
boreand:
11mm(0.43in)fromloweredgeofpistonfor
B27F
1976-1978
8.5mm(0.33in)fromloweredgeofoilscraperringforother
engines.
Diameter,gudgeonpinbore:
MarkingpistonMarkinggudgeonpin
1Blue23.514-23.517mm(0.9257-0.9259in)
2White23.511-23.514mm(0.9256-0.9257in)
3Red
23.508-23.511
mm(0.9255-0.9256in)
MAHLEPISTONS(B27)
B 27
A
1976-1979
B27E
1975-1978
1979-1980
B27F
1979
1976-1978
Height,overall63,4mm62.2mm65.3mm
(2.4960in)(2.4488in)(2.5709in)
fromgudgeonpincentretopistoncrown39.4mm38.2mm41.3mm
(1.5521in)(1.5039in)(1.6260in)
Weight445±3gram
Maxweightdifferencebetweenpistonsinsameengine6 gram
Pistonfloat0.020-0.040mm(0.0008-0.0016in)
Pistondiameter,A-markedpistons87.970-87.980mm(3.4634-3.4638in)
B-markedpistons87.980-87.990mm(3.4638-3.4642in)
C-markedpistons87.990-88.000mm(3.4642-3.4646in)
D
-ts.
Pistondiameterismeasuredatright-anglestogudgeonpin
bore,
8 mm(0.31in)frombottomedge.
Diameter,gudgeonpinbore:
Marking,
pistonMarking,gudgeonpin
BlueBlue23.510
mm-23.513
mm
(0.9255-0.9257
in)
WhiteWhite23.507-23.510mm
(0.9254-0.9255
in)
RedRed23.504-23.507mm(0.9253-0.9254in)
4