please none of that he said she said BS oh i read it on H-T so it must be true. i would like to see pics of all these busted rod bolts that i keep hearing about. also tell us about your rod bolt experience.

also i know ARP are the standard and are very inexpensive but to install is another matter. to install means a rebuild. days of searching have led me to make this thread. thanks guys.

 

i hope this isnt common because my build is gonna be a b20vtec

 

Ive personally seen several rod bolt failures with ls or b20 vtec motors. The arps are like 44 bux at most shops/ online for the ls rods. And they can be installed easily without removing the piston/ rods from the bore. Its not ideal because rods should be re sized for the new bolts, But its going to be a better route than gambling on loosing the rod bolts.

Every ls/vtec ive ever built has got new rod bearings and arp bolts at a minumum. And I always recomend using the vtec oil pump and water pump. But those arent as critical as the rod bolts.

Think of it like this; Your not putting the motor together to baby it. And if the rod bolts fail your going to be out a hell of a lot more money and time than it takes to get the rod bolts in.
You just need the rod bolts oil pan gasket and bearings if you want to do them. 75 bux in parts if that, and a few hours to install.

 

I think of it this way. That OEM rod bolt is the same size as in the d series engines. "I believe a 7mm unlike the gsr is 8mm". Now you are taking the stock block. Slapping a vtec head on it and thinking "oh **** it must be a vtec engine now" and rev to 8100-8500 on a chipped ecu that god knows what is on it or a stock oem gsr/b16 ecu tinking that everything will be fine and ure ecu knows that its runnning a lsv instead of a b16 or gsr engine. Well a few trips later to redline you find yourself a knocking engine.

And to "wreckeddc4". What is the difference between a vtec oil pump and a non vtec.?

 

There is no VTEC oil pump. The water pump is specific to VTEC vs non-VTEC engines (19 teeth for non-VTEC, 22 teeth for VTEC), but the oil pump is more like OBD specific. There's an OBD1 oil pump and an OBD2 oil pump. All OBD2 cars used the same oil pump across the board, from B18B's to B18C5's.

The OBD2 oil pump included, I believe, a crank fluctuation sensor. To use the OBD2 oil pump on an OBD1 block, you have to either use the OBD2 timing belt covers or trim your OBD1 covers.

Or just read this thread: https://honda-tech.com/forums/all-motor-naturally-aspirated-44/how-build-%22reliable%22-lsvtec-b20vtec-1676914/ If you choose not to follow the suggestions there, then don't say I didn't warn you when your frankenstein motor grenades.

 

i get what you're saying but your logic is suspect. your saying that it would be better to install the arp rod bolt even if its the incorrect way? doesnt make any sense. sounds like even more of a risk than stock bolts. i would think it would be better to not risk warping the rod end.

 

has anyone installed arp rod bolts without taking the pistons out? how long did it last and did you spin a bearing in the process.

 

I think you will need to machine the rod bolt in.

 

lol.. I love honda tech.. what you have referred to is FACT.. ls/b20's have the same rod bolts as the single cam little brothers.. The reason that they break is because they aren't designed to rev to 8k rpms, or 9k or above.. there is a reason non vtec b series rev to 7200rpms.. and that single cams rev to 7k rpms ( I'm not a single cam guy, just sayin ) So anyways, at the very very very minimum, spend the extra few bucks, and install arp rod bolts... THIS IS NOT AN INSTALL IN THE CAR JOB.. you need to pull the pistons, and have them pressed in.. and then you need to go through the proper torque procedure when installing the pistons again.. Arp rod bolts stretch, they need to be torqued, loosened and re-torqued.. i do mine 3 times... If you don't install arp rod bolts in an ls-vtec motor, then don't rev it past the ls's stock rev limit of 7k... thus making an ls-vtec pointless.. I sourced a set of b16 pistons, on ls rods with arp rod bolts for 125 bucks.. that's a decent little set up, and not much money in the scheme of things..

FYI.. if you spin a bearing, you will have to tear the motor down, remove the crank and the rod/bearings that spun.. and replace both those parts.. people say machine them, and install over sized bearings.. BUT, it's never as good, or the same.. honda's rev nicely because they are balanced.. so installing oversized bearings to one rod throws that all off.. so add up the price for bearings (75 bucks) and an ls crank (50-150 bucks depending) ls rod (25 bucks) ARP ROD BOLTS THIS TIME (80 bucks) machine work (25-40 bucks) and all the misc. gaskets, fluids ect.. and then tell me it's not worth spending the extra few bucks upfront.. :D

I'm not picking on you, and I hope I don't come off like i am.. just putting it all right infront of you.. hope I have helped.

 

there's a simple formula for this:

longer stroke+higher revs+smaller rod bolts=failure

 

Buy ARP bolts and not have to worry about anything or have a rod go through the block. I just bought a 91 teg and the guy who had owned it before me went through four engines in one month. one blew a head gasket and the other three had thrown a rod.

I'm rebuilding an engine for it right now. just a B18A1 with a 16G turbo.
Bored .020 over. I'm using ARP bolts on everything, and shot peened rods, Blue top DSM injectors (450cc), New oil pump, water pump and other misc parts.

 

get the new rod bolts man like 45bucks

 

you guys keep saying this but its more than 45 bucks. you need machine work, new oil pan gasket. hew head gasket, rod bearings, new ring and more. who would tear down a stock motor and puts it together with old parts? they are a 45 dollar part but hardly a 45 dollar install.

and stop telling me to buy rod bolts. thats not the question. thats the myth im talking about. how many of you guys that posted in this thread actually busted a rod bolt? i want to see how many members here have actually had a block fail from a weak rod bolt and nothing else. if this was such a problem, you would think a few more would chime in.

 

or you could just try your luck. there's probably not a whole lot of people who attempt to defy logic. maybe that's why they're not chiming in.
not trying to rag on you here. i mean, you may get lucky. who knows. but the probability is not in your favor, and the outcome is a lot more costly if a problem occurs.
if the head is going to be off anyways, pulling the pistons isn't much more work

 

I've never actually busted a rod bolt.. BUT I HAVE SPUN A BEARING due to a rod bolt failure.. if they stretch, even alittle, which they do when you rev them high, then you will have an issue.. I don't think that everyone that has a rod bolt issue on lsvtec swaps actually breaks the bolt, but they do spin bearings ect because of the bolt failing.. I hope that clears that up.

 

see now that makes sense. i can see this happening. giving the age of the motor as well. all b series motors are atleast 10 years old. that must be taken into consideration as well.

 

Ive personally broken rod bolts on a stock LS motor with a stock rev limiter and stock everyting. Motor was assembled by a machine shop with new bolts and fresh machine work. So Id say its more than a myth.

 

had stock rod bolts in my all motor ls vtec and revved it to 8900 all day every day with ZERO problems. Motor still runs strong even after being through 3 more people.

 

jesus this is the thread I was looking for.

Op is right, it isnt just 'rod bolts', its rod bolts, water pump, oil pump, bearings, new pistons and maybe rods, reworking the crank, etc!

I could see spun bearings, but a rod bolt snapping? Nah.

 

i would never change rod bolts without reconditioning rods. just as you would never change to main studs without a line hone

 

Had it happen on my stock/original motor, probably around 150k.

Was obviously pushing it, but stock redline and had one rodbolt snap.

Also did two sets of pistons in different motors with the ARP rodbolts.
No machining was done, and they held up fine.

Not saying you should go out and only do that from now on, Just my own personal experience.

 

I have ARP rod bolts with stock LS rods and ITR pistons. No problem so far, I take the revs up to 8K when racing. 50,000+ miles on it and still runs strong.

 

I'm probably going to get bitched at for chiming in but what ever. A while back I had a b20 vtec in my dads track car as a spair motor. Other motor burned up a rod bearing for no apparent reason. Thats another story. Any way, the b20 vtec was literally just a junkyard b20b motor with a b16 head slapped on. No ls vtec conversion or anything. It lasted 8 weekends of pure abuse before it dropped a valve. It was on a road course for about 2 hours each weekend reving to 9k on stock rod bolts.

Would I recommend using stock rod bolts on a rebuild. Hell no. ARP's are far superior, but if your new b20 vtec is in your car just leave the stock bolts and don't rev past 8k. If they break they break. I wouldn't pull a perfectly good running motor and tear it appart to change the rod bolts. Just my opinion.

Also had a 12:1 ls vtec. Lasted 3 weekends reving to 9k before it threw a rod threw the block. The stock rod bolts broke...

Honestly it depends on wether your feeling lucky. Lol

 

how did you run a b20vtec without a conversion kit?? what did you do to supply oil to the head? did you block off the oil supply in the bottom of the head? Did you have the conversion dowels??? or were you just running a b16 head without using the vtec?

 

what year was the b20? i have one out of a 01 crv. mine had 80k on it. does age and mileage of the motor play a large part as well?

BTW. just blew a head gasket so i guess ill be swapping my gsr head this week.