I didn’t consider the differences in rod length. You are right.
Yes you would need custom pistons then, or a rediculously high C/R (hehe). So that’s not financially sound for me.
Though the actual rod will not fail on its own, a strong rod will resist snapping when something like what JETSPD said does fail. A snapped rod almost always equals a destroyed engine.
I haven’t really researched the difference between PR3 and B17a (what’s the modle number?) rods, so I’ll take your word for it.
I was wrong, but the theory is right; a strong rod is still necessary. Don’t forget, they are 10 years old +. Possibly transferring rods from a lower milage wrecked B17a would be the best solution.
the engine i’m building has 125k miles on it. I’m kinda weary about the rods. Dan has told me that they are damn strong, but then again i’ve seen a small handful of guys here on g2ic have problems w/ their b17a rods. So i’m not sure whats up. I’m pretty sure i’m just going to do what elmer did, and have the rods shot peened. Elmers setup is basically exactly what i’m doing to my engine. I took a ride in his car at the wcm and it was pretty quick. I think i’ll be satisfied, at least for awhile, hehe:D
91IntegGS: As long as you are careful and patient then you should be fine. I was just stating the obvious for those who may not see it as obvious. Sounds pretty cool. I don’t want to bump out of STS when I autocross this season so…I maxing out the suspension.
Finally have my block set up nailed down…
-JE pistons .50 over bored 10.5:1
-Crower Rods
-Crank polished
-Flywheel lightened approx. 5lbs
-Block decked
-everything balanced and assembled for me. I don’t want to screw anything up!
any other suggestions? I was thinking about a block girdle(or block gaurd) but don’t really know what good it would do me.
-I’ll post some pics soon of the removal, just have to get my lazy a$$ to put them in the scanner
Originally posted by Brunswck
[B]
Finally have my block set up nailed down…
-JE pistons .50 over bored 10.5:1
-Crower Rods
-Crank polished
-Flywheel lightened approx. 5lbs
-Block decked
-everything balanced and assembled for me. I don’t want to screw anything up!
any other suggestions? I was thinking about a block girdle(or block gaurd) but don’t really know what good it would do me.
-I’ll post some pics soon of the removal, just have to get my lazy a$$ to put them in the scanner [/B]
a block guard is a waste. there is no need for all motor. A block girdle isn’t needed either. I’m not even sure if there is one that fits. If there is, then it wouldn’t hurt to have one, but for a street setup like you’re running its really not needed.
by the way, why such low compression? and why aftermarket rods? Stock rods should be more than strong enough for a fairly modest setup like you’re describing… and at much less cost.
IF YOU GO WITH THE STOCK RODS, GET THEM SHOT-PEENED AND POLISHED. WHEN YOU ARE DONE WITH THAT, INVEST IN SOME ARP ROD BOLTS TO KEEP THINGS FROM COMING APART. JUST DO IT, I’VE HAD BAD EXPERIENCE WITH USING THE OLD ONES. I REV TO 9200 RPM WITH NO PROBLEMS WITH THIS SETUP.
IF YOU GO WITH THE STOCK RODS, GET THEM SHOT-PEENED AND POLISHED. WHEN YOU ARE DONE WITH THAT, INVEST IN SOME ARP ROD BOLTS TO KEEP THINGS FROM COMING APART. JUST DO IT, I’VE HAD BAD EXPERIENCE WITH USING THE OLD ONES. I REV TO 9200 RPM WITH NO PROBLEMS WITH THIS SETUP. [/B]
could you go into detail about what problems you’ve had w/ the stock rods? there have been a couple guys who have had problems w/ the stock rods and i’m trying to gather as much info as possible on the subject. I’m definitely getting my rods shot peened for my rebuild (any idea what rpm that will be safe to?). But i wasn’t planning on upgrading to the arp bolts w/ my b17a… any input on that?
Sorry about the caps lock guys. My stock rods are doing fine revving to 9200 rpm right now. In my opinion, just shot-peening them is a waste of time. Now if you get them polished and then shot peened they will be much stronger. I think the ARP rod bolts is an awesome investment, makes me feel a whole lot better knowing that the stock rods bolts aren’t going to stretch. My last motor threw a rod right throught the block at idle. I can stress enough that if you take a motor apart, putting it back together with arps bolts is the way. They keep thing together in the bottom in a high rpms. Hope this help you out on your buildup.
Originally posted by AllMotorB17 Sorry about the caps lock guys. My stock rods are doing fine revving to 9200 rpm right now. In my opinion, just shot-peening them is a waste of time. Now if you get them polished and then shot peened they will be much stronger. I think the ARP rod bolts is an awesome investment, makes me feel a whole lot better knowing that the stock rods bolts aren’t going to stretch. My last motor threw a rod right throught the block at idle. I can stress enough that if you take a motor apart, putting it back together with arps bolts is the way. They keep thing together in the bottom in a high rpms. Hope this help you out on your buildup.
your last motor? was it a b17a? was it the rod that failed or the rod bolt? and how had you been driving it? were you over reving it? was the motor built? there are so many factors that have to be taken into account.
I wanted to go with aftermarket rods incase i wanted to put nitrous on it which is a likely situation in the near future. Also What is the highest Compression you can turbo your engine? I’m thinking mine will be too high.
Originally posted by Brunswck I wanted to go with aftermarket rods incase i wanted to put nitrous on it which is a likely situation in the near future. Also What is the highest Compression you can turbo your engine? I’m thinking mine will be too high.
aftermarket rods definitely make sense if you’re going nos or turbo. there isn’t really a “too high” compression for turbo. It depends on how strong the engine components are and how much boost you want to run. With 10.5:1, forged pistons and rods, you’ll be set up pretty good for turbo, you just won’t want to run massive amounts of boost. To do that you’d probably want to lower the compression to something a little more friendly towards high boost. but i’m not the guy to talk to about turbo. If you want good answers, check out the FI forum.
When I first started to build up my motor, I purchased Eagle rods, guess what, they did not fit!!! They were way to long, the piston came out the block deck about a 1/4 in. Some people say there were 2 different rods that came in the B17A motor. One which was like the LS rod and one like the true B17A rod. I know that both my B17A motors came with the true B17A rod, not the LS type. I have heard of the B17A motor and the B17A1 motor. If you have either of these, please confirm. Only Crower makes the rod for the true B17A motor, but they ask mega dollars for them. That’s why I went the cheap alternative way. If you plan on making more than 260hp, go with aftermarket rods. Anything below the stock rods should do fine. The B17A rods compared to the B18C rod is wider, thus stronger.
My engine is a 92’ and the code on the engine block is B17A1. I had heard the same thing as regards to the B17A as having 2 different rods but don’t know how to tell the difference
Originally posted by AllMotorB17 In my opinion, just shot-peening them is a waste of time. Now if you get them polished and then shot peened they will be much stronger.
??? What does polishing have to do with strengthening? when you deburr and polish you’re just taking weight off for balancing purposes.
??? What does polishing have to do with strengthening? when you deburr and polish you’re just taking weight off for balancing purposes. [/B]
well, by polishing i think he means taking out all the cast lines and imperfections. It sounds weird be you can actually strengthen the rods by smoothing out all the cast lines and imperfections. Those points cause weak spots in the rods, if they break they’ll most likely break at that point, removing the weak spot from the surface surprisingly enough makes it not so weak anymore. Sorta hard to explain. I saw it demonstrated and explained on one of those Car shows on TNN that usually deal only w/ muscle cars… but i’m sure the concept is the same
what i don’t understand is that dan told me once that shot peening of the rods was just to do what i said above, and take out those imperfections (he calls stress risers). Now i don’t want to dispute the Guru, but i’m pretty sure thats not the main purpose of shot peening. It was my understanding that shot peening actually work hardens the metal. But i’m sure it also smooths out the stress risers, just not as much as a full polish would.
Its my impression though that shot peening would be more important than polishing, since its actually strengthening the metal as well as smoothing out the stress risers a little. Whereas polishing doesn’t actually strengthen the metal itself, it just reduces the chances of them breaking at certain spots.
From what I’ve heard, shot-peeing has more to do with refining the grain of the metal which will, in turn, create a more durable and stronger rod. I have yet to take a true metal working class in school, so I’m not knowledgable, but every material has a grain and every grain has a certain “direction” at a certain arear (sorry about the certains). To acheive the optimal strength of a rod, you want to align the grain longitudinally with the rod length.
Give me 2 semesters and I can tell you a lot more.
Originally posted by GSpeedR
[B]From what I’ve heard, shot-peeing has more to do with refining the grain of the metal which will, in turn, create a more durable and stronger rod. I have yet to take a true metal working class in school, so I’m not knowledgable, but every material has a grain and every grain has a certain “direction” at a certain arear (sorry about the certains). To acheive the optimal strength of a rod, you want to align the grain longitudinally with the rod length.
Give me 2 semesters and I can tell you a lot more. [/B]
it aligns the grain? i’ve never heard it said that shot peening did that. I thought that is what the main reason for getting rods cryoed was. for example: www.onecryo.com but i may be mistaken on if it exactly aligns the molecules.
i’ve done a good deal of working with metals (well, gold, silver, and some platinum). And from working with these metals i’ve seen both work hardening and heat treating (anealing as well as quenching vs not quenching) affect how hard the metal will get.
I wish someone knew for sure about this, because now i’ve heard 3 different reasons why shot peening strengthens rods, and i’m not sure what to believe.
i think it makes intuitive sense to me that one reason shot peening strengthens metal is because it “stops” any cracks from spreading.
for example if there’s a small stress crack in a piece of metal, with continued use/wear it will continue to grow until it hits an end point. and with shot peening the metal it prevents this from happening. does that make any sense to anyone else?
Originally posted by 92GS-R
[B]i think it makes intuitive sense to me that one reason shot peening strengthens metal is because it “stops” any cracks from spreading.
for example if there’s a small stress crack in a piece of metal, with continued use/wear it will continue to grow until it hits an end point. and with shot peening the metal it prevents this from happening. does that make any sense to anyone else? [/B]
i’m not sure if i’m understanding you right or not… but that sounds to me like reducing the “stress risers” idea like dan told me. I’m sure it does do that somewhat, but it seems logical to me that if that was the only thing it did, then we wouldn’t do it, because a real sand and polish would be MUCH more effective at reducing the stress risers, afterall, it would eliminate them instead of just bombard them down and together a little.
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