irishkev90
Member
- :
- 1998 Mazda Protege LX
I'm comparing the Z5-DE specs to a B5-ZE. Major differences include cylinder bore, camshafts and fuel injector flow rate.
Section 1: Bore
The bore of the B5 is 78mm. Other engines with a 78mm bore? The 1.6L engines. According to www.protegefaq.net, all of the 1.6L engines have a 78mm x 83.6mm bore/stroke. The stroke is the same as the Z5, 83.6mm. So, in theory, one could bore the Z5 and use any 1.6L engine pistons. Only problem is the compression ratio. The Z5, as well as the B5, has aa 9.4: compression ratio. All the 1.6L engines have a 9.0:1 compression ratio.
So, major questions based on cylinder bore information:
(1) Are there any high compression pistons made for any 1.6L engines? (B6, ZM, Z6)
(2) Would the 1.6L pistons work with the Z5's rods?
...and if not...
(3) Would the 1.6L rods work with the Z5's crankshaft?
(4) Would the cylinder head combustion chamber need to be englarged to match the larger bore of the cylinder?
Section 2: Camshafts
Z5-DE
Intake-
233* @ .003"
1* BTDC
52* ABDC
40.9000mm
Exhaust-
233* @ .003"
48* BBDC
5* ATDC
40.900mm
Overlap-
6*
B5-ZE
Intake-
240* @ .003"
5* BTDC
55* ABDC
40.888mm
Exhaust-
245* @ .003"
55* BBDC
10* ATDC
40.888mm
Overlap-
15*
The camshafts are completely different between the Z5 and B5. Though, according to www.protegefaq.net, the B6-DE (1994-1996) exhaust cam is exactly the same as the B5-ZE. There is no identical camshaft for the intake, however. The B6-DE's intake camshaft would be the closest with a 230* duration instead of 240*. The overlap would be the same as the B5 (15*), but the B6's intake valves would close 10* before the B5's
So, major question based on camshaft information:
(1) Can I use the B6-DE camshafts in the Z5-DE head?
...if not, I could just keep the stock Z5 cams. Would also save money.
Section 3: Injectors
The stock Z5-DE injectors' flow rate is 160mL/min compared the the B5-ZE's flow rate of 192mL/min. The 1.8L SOHC (B8-ME) and the 1.6L SOHC 16-valve (B6-ME) have an injector flow rate of 192mL/min.
So, major questions based on fuel injector information:
(1) Would either the B8 or B6 injectors work with the Z5?
...if not...
(2) Would running larger injectors make the engine run too rich?
...if so...
(3) Would running the stock Z5 injectors make the engine run too lean?
Thank you with putting up with my questions. With the time approaching of taking out the engine and having it redone, my interest in this approach has been ignited.
Of course, this all depends on if the machine shop can safely bore the cylinders out that much without causing any trouble, such as cracks in the block between cylinders and the like. And I won't know any of that until I pull the engine apart and take it to the shop.
Section 1: Bore
The bore of the B5 is 78mm. Other engines with a 78mm bore? The 1.6L engines. According to www.protegefaq.net, all of the 1.6L engines have a 78mm x 83.6mm bore/stroke. The stroke is the same as the Z5, 83.6mm. So, in theory, one could bore the Z5 and use any 1.6L engine pistons. Only problem is the compression ratio. The Z5, as well as the B5, has aa 9.4: compression ratio. All the 1.6L engines have a 9.0:1 compression ratio.
So, major questions based on cylinder bore information:
(1) Are there any high compression pistons made for any 1.6L engines? (B6, ZM, Z6)
(2) Would the 1.6L pistons work with the Z5's rods?
...and if not...
(3) Would the 1.6L rods work with the Z5's crankshaft?
(4) Would the cylinder head combustion chamber need to be englarged to match the larger bore of the cylinder?
Section 2: Camshafts
Z5-DE
Intake-
233* @ .003"
1* BTDC
52* ABDC
40.9000mm
Exhaust-
233* @ .003"
48* BBDC
5* ATDC
40.900mm
Overlap-
6*
B5-ZE
Intake-
240* @ .003"
5* BTDC
55* ABDC
40.888mm
Exhaust-
245* @ .003"
55* BBDC
10* ATDC
40.888mm
Overlap-
15*
The camshafts are completely different between the Z5 and B5. Though, according to www.protegefaq.net, the B6-DE (1994-1996) exhaust cam is exactly the same as the B5-ZE. There is no identical camshaft for the intake, however. The B6-DE's intake camshaft would be the closest with a 230* duration instead of 240*. The overlap would be the same as the B5 (15*), but the B6's intake valves would close 10* before the B5's
So, major question based on camshaft information:
(1) Can I use the B6-DE camshafts in the Z5-DE head?
...if not, I could just keep the stock Z5 cams. Would also save money.
Section 3: Injectors
The stock Z5-DE injectors' flow rate is 160mL/min compared the the B5-ZE's flow rate of 192mL/min. The 1.8L SOHC (B8-ME) and the 1.6L SOHC 16-valve (B6-ME) have an injector flow rate of 192mL/min.
So, major questions based on fuel injector information:
(1) Would either the B8 or B6 injectors work with the Z5?
...if not...
(2) Would running larger injectors make the engine run too rich?
...if so...
(3) Would running the stock Z5 injectors make the engine run too lean?
Thank you with putting up with my questions. With the time approaching of taking out the engine and having it redone, my interest in this approach has been ignited.
Of course, this all depends on if the machine shop can safely bore the cylinders out that much without causing any trouble, such as cracks in the block between cylinders and the like. And I won't know any of that until I pull the engine apart and take it to the shop.
