hp limitations on stock rods

[tnslide80]

hey how much will the stock rods stand up too?and where's the best place to buy rods?

[themadscientist]

I wouldn't trust the stockers for more than 300hp.

[davidricardo86]

Stock rods are known to be very strong and pretty reliable if your setup is right. I've heard and read on here and other forums that 400+hp is possible. I'd ask Dee on this one. I'd be worried about the rod bolts instead as they have been known to give out if the engine is constantly over-reved. If you keep it at or around 7000 rpm you should have nothing to worry about though. Plus if you're using stock camshafts, reving past 7000 rpm is doing nothing but adding more stress and fatigue to the engine considering stock cams peak out at about 6400 rpm.

If you want to be seeing those kinds of engine speeds you'll have to build up the engine to withstand those types of speeds. Bigger cams, stiffer springs, lighter valves, stronger rods and or bolts, maybe a knife-edged crank, bigger turbo, etc. etc.

[tnslide80]

alright well if anyone has rods where did you get them from i found some pauter x beams for 700 anybody know a better deal ....also ive noticed that people were having trouble finding a good set of rod bolts..im still having a lil trouble finding ca parts...which i know you guys know about that....but any help here is appreciated

[themadscientist]

That might have something to do with the CA18 being older than many members here. It's fading into antiquity and the aftermarket barely cares about us. Better stock up now!

[ch187]

shouldnt the main concern be the pistons. since they arent forged? its always been unclear to me whether they were or not.

[themadscientist]

They are cast. The weakness IS the rods, more specifically the bolts. They are the smallest diameter I have seen on a Nissan. High power CAs eat rods because the bolts fail. Cast pistons are not a detriment, any piston will fail if it is abused and forged pistons don't add the level of strength over cast that many people think. They both melt at the same temperature. Now this is my opinion based upon what I have read and seen and experienced, do with it what you will, there are as many viewpoints on this as there are broken SR20 cam followers . Unless you are building a high-revving engine cast pistons are fine as the loads on the wristpin boss is not such that forged is required. If your mix is out of whack or timing is too agressive and you are detonating either piston will die.

[ch187]

yeah i believe you are totally right. if i didnt have to take my car off the road for more than a week AGAIN i would go ahead and put new rods in but i havent had my ca on the road for a month as it is.

[tnslide80]

so where do you guys suggest getting some rods and rod bolts???? i already have forged pistons......just trying to get all my pieces to this puzzle so i can get this mug boostin

[mbmbmb23]

I bet if you sent ARP one of your OEM rods and bolt pairs they could come up with something compatible in their inventory to replace the OEM rod bolts.

[tnslide80]

does anyone on here have aftermarket rods and bolts???? if so where did you get them?

[ca18det240hatch]

yeah i believe you are totally right. if i didnt have to take my car off the road for more than a week AGAIN i would go ahead and put new rods in but i havent had my ca on the road for a month as it is.

just a curious question....the ring lands on the ca18, are they a weak spot or are they known to be pretty good? I Just noticed nothing was mentioned about them so i thot i would ask

oops, quoted the wrong person. I was asking madscientist for the record

[mbmbmb23]

oops, quoted the wrong person. I was asking madscientist for the record

I beleve some guy on SXOC.com from Norway or Denmark got 500 something (512 maybe) out of his before one bent on him.

-m

[themadscientist]

I've never heard of problems with CA pistons. They always seem to be rod failures.

[bentvalves]

I was under the impression that the ring lands are the weak spot on alot of nissan engines.

An rb25det that I beat the bag out of one summer came down with a nasty case of blow-by. After the motor was torn down, it came to our attention that ALL 6 of the pistons had broken ring lands.

When you say rods are the weak link, do you mean big end failure?

[kapower06]

I believe that the rod failures are due to people not measuring the crank play and not line-boring the mains perfectly straight. Also a very good balance of the ENTIRE rotating assembly is required including the crank, timing sprocket, main pulley, flywheel, clutch, and pressure plate.

I've always thought that the pistons were the problem... I've heard the stock ring-lands were problematic, not so much the rods.

[ca18det240hatch]

sr20 apparently has pretty weak ringlands on their stock pistons. I heard of a guy who tore his apart for a rebuild and when he pulled the pistons out, the ring lands practically disintigrated

[themadscientist]

I have never encountered a failed ring land on a CA piston, nor an SR. I have seen an RB26 fail there but he was beating that motor to hell. I think that the reason the rod knock develops is the bolts are too small and stretch causing the bearing in the big end to fail. That is just my theory based on looking at the parts and the way they fail. I bet if the CA had bolts the size of the SR it would not fail like it does.

I hear so many people blaming the engine for failure when in most cases if you really look at the situation it was operator error that caused it. Even the strongest of uber-expensive parts will fail if you beat on them with too much timing, lean mixtures etc. The rod failure for the CA would at least to me seem to be a weakness vulnerable to revs. I would not worry too much if you don't routinely hang out in the red zone of your tach. I kept my DE way up there all the time and after months of 8500 RPM launches and constant steep rev climbs with the light flywheel when I tore it down I could just barely detect bearing wear on #1.

With My 180 I am not pulling the motor until it tells me to. It has 160000 Km on it and purrs like a kitten. That is close to 10 years with an S14 turbine, countless high speed battle and stoplight confrontations with no signs of blowby, rod knock piston failure. I don't have a magic engine but to listen to the rumors such a thing is an impossibility.

Could it be the fact that this motor has been in my care all that time? Religious oil changes with synthetic oil, timing belt changes every 50000 Km, tune ups, coolant flushes etc? It's a machine, it will work if you care for it, abuse it and it goes POP!

Most of the engines you guys are getting have been beat to hell, overreved by drifters and never taken care of from the time the factory service agreement expired with the first owner. I am suprised your motors run at all, 99% of them should be rebuilt the minute they are dropped off at your house. To look at a motor in that state and say the design is flawed because it lets go as the new owner tries to figure out what he is doing isn't fair.

The only thing about the CA that gives me pause is the rod bolts and it's a brief pause. It is not the uh-oh I feel when I look at an SR's valvetrain, or an FJ's upper timing chain tensioner and nowhere near the foreboding of an early RB26 crank's oil pump drive. If you have the money get aftermarket rods and pistons but if you are on a budget and don't want much more than 300hp the factory rods, checked for flaws with new bolts and a set of new cast pistons will do just fine. Polish the crowns if you want, it helps and only costs you time and fatigue on your jerk-off arm. The money you save can go towards something truly contributory to engine performance and longevity, a real engine management system.

[r34 gtr]

there you have it, straight from the horses mouth.

I understood that if you got the stock rods cryo treated and shot peened they would stand up to one hell of a beating. didnt garage paddy's s13 use stock rods? do i remember this correctly?

I hadnt heard someone stand up for the stock pistons like this before. Looking at the ring lands they could be a little thicker, but for the most part they seem to be pretty good. They are more hoss than the subaru ej205 for sure, considering the differences in piston size. I might opt for some forged pistons only because I am sure there will be a little bit of a learning curve when tuning my new engine management system. Rod bolts are a must. I really want to buy some ARP (or the like) ones, but since no one makes them the best option for me is to have huntsville fastener scrounge some up for me of the same caliber.

definitely got with the engine management. if it is running correctly and you are still breaking stuff, then forged bits are probably a good idea. there are also some exemptions to this, like if you want 600hp. if this is the case you might as well stop kidding around.

[themadscientist]

I am going to see if my 18-year-old cast pistons and stock rods can play nice with my new turbo. If anything busts I'll be sure to detail what happened so others can avoid repeating whatever I did wrong

[mbmbmb23]

........I really want to buy some ARP (or the like) ones, but since no one makes them the best option for me is to have huntsville fastener scrounge some up for me of the same caliber.

Let us know what you find. As I suggested previously, why not send an OEM rodbolt set to ARP and see if they can match them to anything in stock? If not, why not drill out the OEM rod bolt passages and put bigger bolts in there?

-m

[themadscientist]

I tried to do that but they would not reply back after the initial e-mail. I would like to do everything, rod bolt, head studs and main studs.

[boost_boy]

I have never encountered a failed ring land on a CA piston, nor an SR. I have seen an RB26 fail there but he was beating that motor to hell. I think that the reason the rod knock develops is the bolts are too small and stretch causing the bearing in the big end to fail. That is just my theory based on looking at the parts and the way they fail. I bet if the CA had bolts the size of the SR it would not fail like it does.

I hear so many people blaming the engine for failure when in most cases if you really look at the situation it was operator error that caused it. Even the strongest of uber-expensive parts will fail if you beat on them with too much timing, lean mixtures etc. The rod failure for the CA would at least to me seem to be a weakness vulnerable to revs. I would not worry too much if you don't routinely hang out in the red zone of your tach. I kept my DE way up there all the time and after months of 8500 RPM launches and constant steep rev climbs with the light flywheel when I tore it down I could just barely detect bearing wear on #1.

With My 180 I am not pulling the motor until it tells me to. It has 160000 Km on it and purrs like a kitten. That is close to 10 years with an S14 turbine, countless high speed battle and stoplight confrontations with no signs of blowby, rod knock piston failure. I don't have a magic engine but to listen to the rumors such a thing is an impossibility.

Could it be the fact that this motor has been in my care all that time? Religious oil changes with synthetic oil, timing belt changes every 50000 Km, tune ups, coolant flushes etc? It's a machine, it will work if you care for it, abuse it and it goes POP!

Most of the engines you guys are getting have been beat to hell, overreved by drifters and never taken care of from the time the factory service agreement expired with the first owner. I am suprised your motors run at all, 99% of them should be rebuilt the minute they are dropped off at your house. To look at a motor in that state and say the design is flawed because it lets go as the new owner tries to figure out what he is doing isn't fair.

The only thing about the CA that gives me pause is the rod bolts and it's a brief pause. It is not the uh-oh I feel when I look at an SR's valvetrain, or an FJ's upper timing chain tensioner and nowhere near the foreboding of an early RB26 crank's oil pump drive. If you have the money get aftermarket rods and pistons but if you are on a budget and don't want much more than 300hp the factory rods, checked for flaws with new bolts and a set of new cast pistons will do just fine. Polish the crowns if you want, it helps and only costs you time and fatigue on your jerk-off arm. The money you save can go towards something truly contributory to engine performance and longevity, a real engine management system.

This is the bible and will soon enter this forum's archives, so folks need to use the search button. All the thoughts I could think of are here and need not be REPEATED again and AGAIN and again. I will add this: tell-tell signs of stretched rod bolts is when you see your rod bearing shells both pressed on to the crank's journal, when the bearings are not fully seated in the rod's bearing cradle and when you have just plain-'ol spun a rod bearing. If your bearings are all locked in place when you remove them, your rod bolts have not been stretched to the point of needing servicing and a fresh set of bearings will be all you need.

As for the pistons, I've pushed them waaaay past 400whp and they hold up just fine. Like TMS said, if you're running too much timing or running the engine lean, even the wisecos or the CPs will crack their ringlands and I have personally destoyed some wiseco pistons when I was using the JWT stuff back in 1999-2000. This subject is done and Mike, unless you have any objections, I'm locking this thread.

Dee