Good discussion... very good information guys.

I'll throw my 2½ cents in on connecting rods.......
My 1st choice if I were building Taner's motor would be Oliver billet. I wouldn't be interested in a lightweight steel rod... not with the nitrous he's pushing. If he ever wanted to take the car off the streets, an aluminum rod would help his crank out a good bit by acting as a shock absorber. I'd also stay away from lightweight wristpins, going with a C&A taper wall instead.
Second choice in rods would be a Howards billet but Lunati, LAE, Carillo and company, would definitely get the job done.

Specifics.
The best bolt to use is an ARP (L19 material). I believe the clamping load for them is in the ~250,000 psi range.... that versus the 8740 bolt's 190,000 psi. Make no mistake, the L19 is the mother of rod bolts... well worth the extra dough. There's also a material that falls in between there but there's like ~$20 difference in cost between it and L19.... should be a no brainer on which to get.

Some random thoughts on bolts.....
Use a torque wrench, but with rod bolts you're looking for stretch, not preload. The manufacturer lists specific stretch requirements for their bolts. Buy a stretch gage and do it right.
On other bolts, use torque to angle (TTA).... a clicker torque wrench can get you in trouble. According to the guys at ARP, friction impedes consistent clamp load values. So you have to overcome so much friction to achieve load..... and friction is hard to predict, even when using specified lubricants. Thus TTA is the way to go because you aren't relying on torque value, but the helix and pitch of the thread to acheive a specific amount of load.
Which brings up another matter..... use the recommended lubricant. Alot of old guys who think they know better, chunk the stuff in the trash and get out the 30W oil...... as my gandpa used to say, "That's plumb stupid!". Look at the R&D that went into the design of those lubricants.
Use torque cycling. Bolts relax once torqued and that amount of relaxation varies. The guys at ARP suggest cycling a bolt to 50% of it's final torque 5-6 times before taking it to final torque... which has a burnishing effect on the threads. That way you're overcoming less friction and increasing the clamp load of the bolt because it will stretch more after cycling.

Just some random thoughts, but ARP put out a good amount of tech here some years back.... at least that's where I remember reading up on this. I do all of the above when I build an engine and I can't say that I know too many other guys who do.... but mine have a habit of staying together for a while...... of course I'm **** too.
Honestly though.... most guys I know, have never even heard of torque cycling.

-Mindgame

 

now this is what i call a response!

ok let me say thanks to all of the good info. correct me if i am wrong but 750 rwhp min. is about 865 fwhp. i spoke to a tech person at lunati today, he said he knows of people running about 900fwhp, without any issues. so that is good news, i also do NOT spin the motor above 7000rpm. he stated that was aslo in my favour. however i do have DFI waiting for an install and would like to do a sheetmetal intake in the next couple of years.

i only have about 25-30 full bore nitrous runs on the rods. of course a whole bunch of motor runs to go with that. he also stated they have an other forged rod that is good to 1700 fwhp. i know the stuff isn't cheap but a few hundred extra bucks is worth it to me! call it a piece of mind issue. i would rather have overkill than granade the block that has alot of work in machining tied up in it.

89ProchargedRoc,

hmm car sees mostly street driving, and of course some drag racing! i would figure i will run the car at the track on the bottle for a total of about 12 more runs this year. rest of fun will be had trying to get that elusive 10 sec. slip on motor. i don't plan on going any higher than the 300 shot especially knowing that i am over the rods advertised limits!!!!! they are rated for fwhp..right?????

Bret,

thanks for your input, i kow i won't be getting titanium rods anyways, lol!!!!! i am just planning ahead. rods will be on the realistic horizon for me over the winter. besides i have a fence a roof to replace and a new garage to build but i will check out gp's and prices at that time.

Big Rick,
hmmm so that is what is in your beast (which i attempted to get you strapped into at NvsS, in the finals) but rick, what if i want to run faster than a 9.47 j/k! cool to know that is what you trust to have in your motor. i would eventually like to push the envelope a little bit more, but i won't even think of attempting it if the motor wasn't meant to handle it. the motor may take a 400 hit but i don't want to try it until i have done the upgrade. the motor is working great now, and the last thing i want to do is get greedy!
my moto is greed kills motors...not nitrous!

OldSStroker,
would you goto the better rods for a 900fwhp small block? i guess that is what i am looking for in an answer. thanks for your input!

RSkrause,interesting info in the fact you are running the same rods. have you dynoed the car yet? just curious, i am sure you can tell by now that i don't want to push the limit of the rods. overkill is a good thing

Mindgame,

thanks for the enlightenment on the bolts, and all of the excellent detail in reference to use and installation.

i am leaning towards a Billet rod, Oliver's worked fine for Geogre Baxter and I don't imagine i will ever go that far with this motor, then again i never thought i would've come this far, lol! that is why the rods were a good choice when the motor was assembled.

 

i chose Eagle H beams.. mainly for the price..

if I ever gernade this motor, I think i would probably build a SBC with billet rods. I know several people making 800+rwhp with eagle h beams with out problems.... and I think that the LT1 block is going to be groaning above this..

So basically, I don't wanna risk trashing $$$ rotating assembly if the block fails...

now, if I spend $2k on a block, I wouldn't wanna risk a cheap rotating assembly coming appart and killing the block!!

 

Hey Taner,

If you ever take the car down to very limited street use throw a set of Fowler alumn. rods in. There great rods not to mention will deal with some street use as long as you give the car proper warm up time before you street drive on them. Alumn rods are the only way to go if you ever decide to start spraying crazy levels. They deal with the nitrous better than a steel rod. A steel rod will beat the hell out of the bearings and the crank. Alumn rods.Hellfire rings and tool steel pins I'd say your good to go!

If you throw in a set of Eagle ESP rods these rods will take what ever you can throw at them. I know of alot of guys that run nitrous combinations making 1000hp using them without any problems. I my self have ran them in the past and have them in my nitrous LT1 motor and that motor is over 13.1 comp with 400 plus hp nitrous loads. What the hell its not as if the motor will be making 900 to 1000hp all the time just when on the bottle, the reat of the time it will spend its time at say 500 to 600hp.

Those Olivers are a great rod but I have a buddy that has seen two sets let go with less than 10-20 passes on each set just as soon as he's on the bottle and the power level goes over 1200hp they let go. It's a great rod up to 1200hp but after that they do not like nitrous beyond that! At least not in a 632ci!

Funny thing has it I was just talking to Wade today and your name came up in the conversation. He was telling me he feels theirs more left in that motor of yours regarding power. You should ask him what he would recommend. You sure can't get much better advice then what Wade will give ya. Theirs a guy that runs what he builds and can actually tune for nitrous. You might be suprised what he will recommend to ya. You might no have to run out and spend $1200.00 for a set of rods.

With all these super fast hot rods that are out I can hardly wait till I can get out to race a few and loose my money in the F body shoot outs! Its only day's away!

Good Luck!

Jim

 

Jim,

car is a street car first, and i would agree with wade i think the car has better numbers in it. even on the 300 shot! i just need some september weather to get here! this heat doesn't help the car run any quicker. the week after bowling green i had it back at st.thomas and it ran a 9.65 off of the trailer and then as soon as it heated up it slowed down to a 9.729 and a 9.722.

aluminum rods are OUT of the question for me, street car first race car second. i don't mind freshening up the motor every couple of years if i have to. a small price to pay to keep it ALL together. i will be putting in lifters on a yearly basis, all because i chose to drive it on the street primarily. i have an extra set of solid roller lifters i will be sending out to have rebuilt by comp cams. so when i swap them out i will have the set i pulled out sent back to be rebuilt. nobody ever told me it would cost so much

i won't ever get near 1200 fwhp so i am not too worried. i would like to be able to throw 350 into the motor and not worry about it, maybe even a 400 shot. but that is absolutely it....i swear!

 

Taner: just to respond to your question, I wish I did know how much hp it's making now. We couldn't get any decent dyno runs due to converter slippage. The converter is back at Coan to be "tightened up". I don't know if it will ever produce accurate dyno numbers at this point though. Just have to see if it works at the track, and use the dyno for getting the AF ratio right.

Rich Krause

 

If I were pushing 900 fwhp I'd certainly be into about the best rod I could find. But then, I'd not try that on an LT1 block. It would be a much stouter one.

BTW, the heat treating and billet manufacturing I discussed are very close to what Oliver does.

IMO, getting "clean" defect free steel and heat treating it to the desired strength and desired grain size makes a more durable rod than a forged rod with good grain flow. I'm not a grain flow type of guy. Just an opinion, not ex cathedra.

As far as bolts go, the rod should be equipped with a bolt that matches the stength of the rod. 1000 hp bolts in a 500 hp rod still only give you 500 hp of stength. It's not more clamping force you get with a stronger bolt, it's less stretch when the piston tries to go out the top of the block on the exhaust stroke. During the power stroke the bolts are resting. Heavy shots of nitrous need rods strong in compression; the bolts are loaded when the rod is in tension.

If a very strong 3/8 bolt is adequate for the rod, going to a 7/16 bolt, which is about 1/3 stronger in the same bolt grade, just adds bolt and rod weight which puts more load on the crank. Same thing for rod weight. So, I'd choose the smallest/lightest rod and bolt combo which held my hp (and pocketbook).

Did anyone else like Ken's pun?

quote: "I dont think it warrents its own thread (rod bolts)..."

 

Just curious, I heard Acura had problems with the Titanium rods in some NSX cars that due to expansion rates would cause rod bearings to bind and score crankshafts. Is this a problem one must consider when using titanium or is just because Acura is goofy?

 

This is off the rods, but one thing i did when tightening my heads was use a pointer and a hammer and tap all bolts very lightly a few times... and many of the bolts would tighten up to a full turn before getting again the 70lbs -ft of torque...

 

It's always interesting to see what guys expericenes are.

If I was going to Al rods it would be a BME rod.

On my side of the story a 900hp engine with a Eagle H is very lucky and living on borrowed time. You only get a certain number of cycles on a rod and I'd rather have one that has more cycles under it's belt than one that has less. Bent rods or broken rods are not pretty. If you have to spend $300 more now to save the whole bottom end later (basically take your total investment and throw it out the window) then you gotta realize, **** happens.

I'm not one to experiement with that since if it goes BOOM and I build it, it's my fault. I'd love to make things that keep coming back to me, (some engines are designed like that to use the lightest parts out there) but morally I can't do that. Bussiness is always good but unhappy campers aren't.

Just my thoughts on that.

The Acura thing is interesting. I'm sure the engineers there took into account the Ti clearances, it's scary if they didn't. Who knows why the bearings failed. Might not be the Ti rods.

Mindgame,

That is about the most detailed rod bolt tightening sequence I have ever seen. It makes sense.

I gotta go with the Old guy on rod bolt selection though, a 500hp rod only needs a 501hp rod bolt. If it's not the weak link then that's good but too much of something is never good.

That brings up a funny related part. The Audi R8 LeMans cars were definately a German Design, they made as many bolts and fasteners in that car the same size to make changing them easy. The Bentley that won this year is based alot on the Audi's (the direct injection engine is the big commonality) but it was English engineered and they used the lightest smallest bolt everywhere that would get the job done. Both cars are impressive.

Bret

 

That means there are more means to an end...

You say eagle H-beams are on borrowed times... have you seen them break??? I am just curious since that is the crank and rods I got and I would love to stay under the limit.. I am with the impression that given good tunning my engine is unbreakable.. Then again I am not planning on going further than what a simple S-trim or T-trim can push on my engine, but I would like to know if im ok with them though..

I get the idea that shelling out $300 to save a complete engine is not much $ to spend, in fact, just pulling out the engine and all the work associated with it.. its worth the extra $. But when money is a bit tight what do you do? Its not the same thing $600 for a set of rods than $1200... Now.. you wouldnt put a $1200 set rod on a $700 crank now would you? so then its a lot more $ in the investment so.. some people just risk it and some people win others loose...

I always had the idea that forged was always stronger than billet.

 

i have never seen or heard of ANY type of H-beam rod breaking due to horsepower. Incorrect installation, bad balacning, or other things going wrong yes i've seen that

but

i've never heard of a h-beam rod breaking due to just horsepower/rpm

---Larry @ ASSC racing told me that back when they had the original Big Red (they are now on Big Red III with a F-3SC procharger chain drive that went a best of 6.64 @ 221) they actually used the heavy h-beam rod with no problems what so ever. They would beat the **** outta them with well over 1000hp considering they were going mid 8s

As for the rod bolt issue, i do not believe the L19 ARP rod bolt is the strongest. The last i heard the rod bolt option that Carillo gives on their rods, i believe its called SPS i think or even possibly Carr rod bolts are stronger. The SPS rod bolt option from Carillo on their rods is like a $300 option

 

For all the people that feel Eagle Rods shouldn't even be used in there 5hp lawn mower because it just can't take big power then check this engine builder's site(Shafiroff is a well know engine builder to say the least) and just one of his combinations is making 958hp and wouldn't ya know it he just so happens to be using a Eagle Rod.

www.shafiroff.com/555_bigduke.asp

The thing is the Eagle rod is not the best but by far not the worst nor is it a weak rod! I guess if you feel the need to go and spend $1,200.00 on a set of rods for all those mega power rod breaking small blocks out there well thats OK to. Be really honest with your self how many LT1's have you ever seen kicking out a rod of this caliber? You have to kidding me these motors don't make hundreds and hundreds of horsepower for god sack. And even the blown LT1's, I wish had a quarter for every guy that was telling me he had a 700,800,900hp blown setup and when it ever cam to lay a number down at the track there lucky if they get out of the 11's or dyno time its always the same story and that is "My blower belt was slipping" With only a very small few guys around are really making that kind of power with the LT1 and to tell ya the truth it shows!

All I'm trying to say is why nock a part just because its cheaper than the most exspensive rod out? That doesn't mean all cheaper parts are dog**** all the time.

I figured I'd kick in seeing that my feelings where getting hurt because you guys doggin the rods I'v used. LOL!

My rods are probably holding together because in all reallity the engine makes only 200hp off the bottle when it should be making 600 and the when on the bottle spraying 400hp out of the hole the nitrous is probably killing power due to my ****y tuneup. So I figure motor plus nitrous for total of 150 Eagle Rod breaking horsepower!

Peace,

 

I can't remember ever hearing of an Eagle H-beam rod failure in an LT1.

I use them, budget mandated.

I don't know about horsepower, but I've been 6.0s in the 1/8th in a 3650lb car. I've also data logged 27# boost, but I usually run around 17#.

 

Yes I actually would because I'm trying to fix the weakest part of the equation and a $700 crank is most likey a 4340 Forged setup. Cranks only cost more for a few reasons, lighter, made out of billet or it's a lower demand part. The crank is good to 1000hp then why when you have a 700hp rod would you not upgrade them to the same or better strength. The engine is only as strong as it's weakest link.

Quote:

I always had the idea that forged was always stronger than billet.

Read Old SStrokers post above it all depends. Actually Arrow's SBC rods are made just like he describes in the fully machined forging. Where they are cut everywhere more than 1/16 off of a forging.

Guys, I'm not saying that a Eagle Rod is bad, I've put them in $20K engines. I always think it's funny the tone a guy's thread takes when he is running one of the parts in question. We are not attacking you or saying that they parts are junk. I'm just saying I personally wouldn't do it.

My suggestion is that an extra $300 in a buildup of the engine for stronger rods can save you tons down the road.

For all the guys out there saying have you ever seen a LT1 break a Eagle? Have you ever seen a LT1 stock crank break?

Look at Sharoff's upgrades on that same motor. Rod Bolt uprade, Crower Steel Rod Upgrage, Oliver Billet Rod Upgrade.

BTW a Eagle H beam for a big block is 815g of forged steel and is only recomend for 800hp. That extra 160g of material does help make it stronger.

One thing we have to remember is that load will break rods but not as fast as RPM will.

Taner, your rods should be o.k., but if you are going to take the engine apart to ring and bearing it, you might as well change the rods. Then again we don't know how strong everything else is.

Bret