Sr Main Bolts
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Why So Serious?
Joined: Feb 2005
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No real need to go ARP mains unless your doing BIG things. 54C bolts are actually 30% stronger than redtop bolts, they are a tad beefier.
There is much more involved if you were to go with ARP main STUDS Vs oem BOLTS. Studs can alter the SR crank journal line bore, therefore you should consider align honing your bottom end......
If you look at how a main stud engages and tightens vs. a bolt the difference is readily apparent. Bolts tighten via course threads into the block, you have torque on the bolt head as well as the threads while tightening. Studs thread into the block, then when tightening, threads in the block are completely engaged, the only friction is the small surface area under the head. You are pulling machined metal directly into machined metal via fine thread (more threads per inch). Just no way to compare the two.
Studs use a higher torque at assembly, therefore, would distort the main caps differently than the factory bolts would. Running an align hone thru the mains would assure they were round and straight with each other. Just one more step in assuring everything runs true, and that you get the correct crush on the bearings, and equal oil clearences across the mains.
That's why its recommended that you indeed get your crank journals/caps (bottom end) align honed if you go with studs. If you skip machining/line hone on studs and you go tighten up your mains and your crank doesn't spin or is difficult you'll know exactly why...
I actually think Mazworx has fixed the 1 or 2 studs that hit the upper oil pan. They shortened a stud or two so you would not have to chop and weld your pan...
A 6 week Maz backorder = bummer..
wait or go 54C..
There is much more involved if you were to go with ARP main STUDS Vs oem BOLTS. Studs can alter the SR crank journal line bore, therefore you should consider align honing your bottom end......
If you look at how a main stud engages and tightens vs. a bolt the difference is readily apparent. Bolts tighten via course threads into the block, you have torque on the bolt head as well as the threads while tightening. Studs thread into the block, then when tightening, threads in the block are completely engaged, the only friction is the small surface area under the head. You are pulling machined metal directly into machined metal via fine thread (more threads per inch). Just no way to compare the two.
Studs use a higher torque at assembly, therefore, would distort the main caps differently than the factory bolts would. Running an align hone thru the mains would assure they were round and straight with each other. Just one more step in assuring everything runs true, and that you get the correct crush on the bearings, and equal oil clearences across the mains.
That's why its recommended that you indeed get your crank journals/caps (bottom end) align honed if you go with studs. If you skip machining/line hone on studs and you go tighten up your mains and your crank doesn't spin or is difficult you'll know exactly why...
I actually think Mazworx has fixed the 1 or 2 studs that hit the upper oil pan. They shortened a stud or two so you would not have to chop and weld your pan...
A 6 week Maz backorder = bummer..
wait or go 54C..
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No Front Bumper Mafia crew#1 since 04'
The original 350Z Blue 240sx
No Front Bumper Mafia crew#1 since 04'
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No they arent, crankshaft is different, rods are different and use 19mm bearings vs 17mm in the S chassis engines, there are other differences, i'm not sure on the main bolts, but i'd take his word for it on the 54C's being a stronger fastener.
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Why So Serious?
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if you say so..
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No Front Bumper Mafia crew#1 since 04'
The original 350Z Blue 240sx
No Front Bumper Mafia crew#1 since 04'
The original 350Z Blue 240sx
Doesnt see what you did
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How many 54C (GTiR) motors have you touched ? Disassembled ?
Hell just take a look around at a few parts sites, notice the GTiR 19mm rod bearings, and the machining that mazworx offers to use gtir rod bearings on your rods ? Yup again because of the GTiR differences....
no
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Thread Starter
Why So Serious?
Joined: Feb 2005
Posts: 3,242
Likes: 0
How many 54C (GTiR) motors have you touched ? Disassembled ?
Hell just take a look around at a few parts sites, notice the GTiR 19mm rod bearings, and the machining that mazworx offers to use gtir rod bearings on your rods ? Yup again because of the GTiR differences....
Hell just take a look around at a few parts sites, notice the GTiR 19mm rod bearings, and the machining that mazworx offers to use gtir rod bearings on your rods ? Yup again because of the GTiR differences....
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No Front Bumper Mafia crew#1 since 04'
The original 350Z Blue 240sx
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I'm glad that Gumbrick posted up about this. I did 54C main bolts on my last motor as they're a lot stronger and cheap. You don't hear hardly anything about mains bolt failures, but it's hard to justify not spending $20-40 on some bolts when it's so small compared to the rest of a rebuild cost. BTW, 54C mains have also been referred to as Nismo mains.
Lets face it. The bottom end on these motors is pretty damn strong. Do whatever you prefer, because it would really only make a difference on about 3-4 of the local motors around here.
Lets face it. The bottom end on these motors is pretty damn strong. Do whatever you prefer, because it would really only make a difference on about 3-4 of the local motors around here.
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is it me or is it every thread you post in you want to start an arguement? gtir is completely different except the crank. Congrats you can quote whats off there website. I think the question at hand was answered with 5 yes's and 2 no's ,now if you want to put something helpful and something thats not augmentative be my guest.
You posted that the engine's were identical, I corrected you, you then decided to post something questioning that being fact.
The question at hand was should you get new bolts or not, which was answered by one person, whom you questioned, if you want to take peoples advice instead of just questioning it, repetitively when it's given, be my guest, otherwise why ask ?
