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| Revision as of 10:32, 23 July 2015 ddgonzal (Talk | contribs) (->Main Bearings) <- Previous diff |
Revision as of 08:50, 2 January 2016 ddgonzal (Talk | contribs) (->Thrust Bearing) Next diff -> |
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| = Thrust Bearing = | = Thrust Bearing = | ||
| See: [[Thrust Clearance]] | See: [[Thrust Clearance]] | ||
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| + | = Main Bearing Cradle = | ||
| + | Although probably unnecessary, you can fabricate a main bearing cradle (ladder frame) such as many modern engines have. The theory is that it stiffens the block for high HP applications. | ||
| + | |||
| + | Garage Nakamura cradle | ||
| + | <br>[http://datsun1200.com/modules/myalbum/photo.php?lid=26234 http://datsun1200.com/uploads/thumbs/26234.jpg] [http://datsun1200.com/modules/myalbum/photo.php?lid=26233 http://datsun1200.com/uploads/thumbs/26233.jpg] [http://datsun1200.com/modules/myalbum/photo.php?lid=26232 http://datsun1200.com/uploads/thumbs/26232.jpg] | ||
| [[Category:Engine Mechanical]] | [[Category:Engine Mechanical]] | ||
Revision as of 08:50, 2 January 2016
If you get new bearings, keep in mind that inexpensive bearings do wear over time. Datsun used triple alloy bearings which do not wear out, but only if the engine loses oil pressure they will be damaged, or if debris gets into the oil.
Contents |
Measuring Bearing Clearance
Measure Bearing Crush when installing new bearings.
It is difficult to tell by visual inspection if bearings are worn. It is normal to have some pattern on them.
Direct measurement: The best way to check is to use plastic thread. Buy the Plastigauge (just a couple of dollars) and put it back together. The amount the thread is squished tells how much actual clearance it has.
Plastigauge see wikipedia article
Indirect measurement: Measure the journals with a precision micrometer, then calculate the clearance.
It is suggested to measure clearance after fitting/refitting bearing shells to confirm actual clearance.
Datsun Factory Service Manual:
Measuring Main Bearing Clearance
Regarding rod bearings, it says "Measure connecting rod bearing clearance in the same manner".
Connecting Rod Bearings
A12/A13/A14/A15 12111-20910 BEARING-CONNECTING ROD STD <> 12111-20900 12111-20900 BEARING-CONNECTING ROD STD 12111-20901 BUSHING-CONNECTING ROD UNDERSIZE 8 12111-20902 BUSHING-CONNECTING ROD UNDERSIZE 12 12111-20903 BUSHING-CONNECTING ROD UNDERSIZE 25 (0.25 mm undersize) 12111-20904 BUSHING-CONNECTING ROD UNDERSIZE 50 (0.50 mm undersize) 12111-20905 BUSHING-CONNECTING ROD UNDERSIZE 75 (0.75 mm undersize) 12111-20906 BUSHING-CONNECTING ROD UNDERSIZE 100
1984 Nissan Competition Catalog said: The -25720 ... bearing shell produces the most desirable bearing clearance for racing purposes when applied to a standard size crankshaft. The other shells exist in order to obtain proper clearance when compensating for the variations in the crankshaft or connecting rod journals.
8 each required:
* 12111-25720 .0590"
* 12111-25721 .0588"
* 12111-25722 .0585"
* 12111-25723 .0592"
* 12111-25724 .0583"
Main Bearings
Crankshaft bearings
BEARING SET A12/A13/A14/A15 * 12207-H1001 SET-BEARING STD <> 12207-M7201 <> 12207-H1000 $71.58 * 12208-H1000 SET-BEARING 0.20MM * 12209-H1000 SET-BEARING 0.25MM * 12210-H1000 SET-BEARING 0.50MM * 12211-H1000 SET-BEARING 0.75MM * 12212-H1000 SET-BEARING 1.00MM
1984 Nissan Competition Catalog said: The ... -H2310 bearing shell produces the most desirable bearing clearance for racing purposes when applied to a standard size crankshaft. The other shells exist in order to obtain proper clearance when compensating for the variations in the crankshaft or connecting rod journals.
MAIN BEARING (#1/#5, SHELL THICKNESS) 4 each required
* 12215-H2310 .0720"
* 12215-H2311 .0718"
* 12215-H2312 .0715"
MAIN BEARING (#2/#4, SHELL THICKNESS) 4 each required
* 12231-H2310 .0720"
* 12231-H2311 .0718"
* 12231-12312 .0715"
MAIN BEARING (CENTER, SHELL THICKNESS) 2 required
* 12247-H2310 .0720"
* 12247-H2311 .0718"
* 12247-H2312 .0715"
Thrust Bearing
See: Thrust Clearance
Main Bearing Cradle
Although probably unnecessary, you can fabricate a main bearing cradle (ladder frame) such as many modern engines have. The theory is that it stiffens the block for high HP applications.
Garage Nakamura cradle
