Re: [DML] PRV-6 Differances

[ttanaka504@xxxx]

Dear List:

I was thinking about I should tell or not this information...but I 
got many help from this list and I think I should shire what I know...(Please 
do not misunderstand I thought I was not sure this information is useful to 
you or not)

I was researching B28F and B280F because I think newer parts are 
better quality and it has extra 15 hp. You may think 15 hp is too little, but 
15 hp is a lot for 130 hp 's NA engine modification. Also if I use newer 
component, I can modification from base 145 hp. What I am thinking now is 
polish intake and exhaust port (very dangerous if you do not know anything), 
shot peeing and balancing (polish and check weight and size) most engine 
components. I may use Aluminum cam gears and pulleys and titanium bolts and 
nuts. I am still researching. I am going to start this project next 
year.(After I got big money...) 

According to Haynes Volvo 740& 760 Automotive Repair Manual
Differences between B28F and B280F
Identification:
B28F Continuous injection system
B280F LH-Jetronic fuel injection
Compression ratio
B28F 8.8:1
B280F 9.5:1
Liner seal thickness:
B28F 
blue mark 0,070 - 0,105 mm
White mark 0,085 - 0,120 mm
Red mark 0,105 -0,140 mm
Yellow mark 0,130 - 0,165 mm 
B280F
Orange mark 0,098 - 0,134 mm
White mark 0,118 - 0,154 mm
Blue mark 0,138 - 0.94 mm
Yellow mark 0,130 - 0,165 mm
Pistons Diameter
B28F Grade A:90,970 - 90,980 mm B:90,980 - 90,990 mm C: 90,990 - 91,000 
mm 
B280F Grade A:90,920 - 90,930 mm B:90,930 - 90,940 mm C: 90,940 - 90,950 
mm
Intake valves
Head diameter
B28F 44mm 
B280F 45.3mm
Valve head angle
B28F 29.5%
B280F 44.5% 
Exhaust valves
Head diameter
B28F 37mm 
B280F 38.5mm
Valve head angle
B28F 44.5%
B280F 44.5%
Valve seat angle:
B28F Compound(60-30-15)
B280F 45
Camshafts
Max Lift (at lobe)
B28F Intake 5.44mm Exhaust 5.94mm 
B280F Intake 5.96mm Exhaust 5.43mm
Crankshaft
Connecting rod bearing journal diameter
B28F Standard 52,267 - 52,286 mm Undersize 51,967 - 51,986 mm
B280F Standard 59,971 - 51,990 mm


Blacknight