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Discussion Starter #1
whats up, I'm Lucas, and I'm pretty new to the Suzuki world. I got a job to built an all motor 10:1 compression, 1.3l 89 sammy,
this guy is not a mechanic but learning, he tried to built it himself. So far its got a bigger cam, webber carb, 4 to 1 header, the head just got out of the shop.

we have a problem, when he got the new pistons, he got new rods, ok, used rods, he installed the crank and new bearings and the crank turned, but when he installed the new rods and pistons, with new bearings. then he could not turn the crank at all.
this is where i came in. the new rods have a thicker beam then the stock 1.3l rods, he swears they are stock, can't be the don't match. but the bore measurement on the new rod measures out to the book. but when i do the math, we are getting .0503 to .0502 for bearings gap. none the bearings list show anything smaller the .080. what am I possibly doing wrong?

is my math off?
did he get a later model rod or 1.6l rod?


thanks for the help,
Lucas.
 

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Are those "inch" measurements? :huh:

.0503 to .0502 for bearings gap. none the bearings list show anything smaller the .080. what am I possibly doing wrong?
Do you mean .005"+ range?

And the .080 statement is confusing.

You need Plastigauge to more accurately determine installed bearing clearance.
http://www.plastigaugeusa.com/how.html


Wider con rod beams. Aren't you concerned about weigh, mix / matching of parts and the need to now BALANCE the rotating assembly? :confused:

How about connecting rod SIDE clearance? Are the bearings binding on the chamfered edges of the crank journal?

What about piston to cylinder top / head clearance (deck height)? Have you done the math to determine combustion chamber CC's and compression ratio? Valve to piston-top clearance? Which thickness head gasket to use to achieve your goals?

I fear that you might be in over your head Lucas.
 

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Discussion Starter #3
Couldn't find any Plastigauge on the island. But we have mics and calipers. I have all the measurements, but i can't post the pic from my phone. After taking the rod bore and the crank, measurements I'm getting is. 103 to .105 for the gap for the bearing. Divide that by 2, to get bearing size, minus .002 for oil clearance. All the bearing sizes in the book so nothing that thin. I'll get a pic of the old rods with the new.
 

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First - the term stock 1.3l rods is meaningless - there are two very similar (near identical visually, you have to know here to look to find the differences) 1.3 Suzuki engines with different displacements (G13A/G13B) and at least three different versions of the G13B making for a total of FIVE different possibilities - having said that - those rods should all interchange as far as fitting the crank journals goes - the differences are in the length, strength and little end configurations.

Like Max - I'm puzzled by your measurements and the 0.080 for the bearing - you seem to be measuring the rod bore and the crank journal and attempting to determine the required bearing based on those dimensions - as far as I know the norm is to measure the crank journal, determine if it's a) out of round and b) within tolerance and then either fit standard bearing shells or regrind and fit undersized shells.
 

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I should think that the rods are from a G13B engine from a Swift GTi, its a fairly common upgrade.
 

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It's not a direct swap Rhino - the 8v wrist pins are interference fit in the rods, whilst the GTi takes a larger diameter, full floating wrist pin, retained by circlips.
 

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Discussion Starter #7
how to do i identify the different rods? he got these rods off ebay, and im going back to remeasuring them, in 8 different places to make sure they are not out of round. If they are he got screwed, and we are using the stock rods with the new pistons, i know the color code for the right bearings for those rods
 

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Sorry - I can't tell you how to identify the different rods - I checked and found five different part numbers for 1.3 rods, but, for the most part, I have no idea what the visual differences are.

What I mentioned earlier on the difference between the 8v rods and the GTi rods was from memory and then confirmed by looking at the pistons, which I just happen to have on a shelf here.

Out of curiosity, why is he changing the rods? In my opinion the "stock" 8v rods are more than adequate for any normally aspirated motor.

FWIW, I'm running an 8v "hybrid" 1.3 - GTi crank and girdle in an 8v motor with +0.020 OS, flat topped high compression pistons and the original rods, with 30,000+ very "enthusiastically" driven miles since the build.
 

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to make sure they are not out of round
"Re-sizing" the big end is a standard Auto Machine shop practice when reusing old rods. The bearing cap bolt mating surfaces are lightly machined, rod assembled / torqued and then the bore is "honed" to spec. Rod deflection (bent?) is also checked at the same time.

That will bring THAT portion of the rod to terms, but in regards to if they are the "correct rods" for your application? Hard to tell but it depends on rod length, small end size / condition and if they are compatible with whatever pistons you use to achieve the correct deck height.
 
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