rskrause

Currently I am running Lunati Pro-Mod rods with 220,000psi rod bolts. My present setup makes 733rwhp with a 6,000rpm redline. The setup I am planning for next year will be in the range of 900-1000rwhp on the juice and ~650-700 with just the blower. The nitrous will be used exclusively at the track. The new setup will not be revved any faster than now - 6,000rpm max.

Do you think the Pro Mods will do the trick? $1,200+ for Oliver billet rods would add a lot to the cost. So I am hoping that the Pro-Mods will do the trick. They are supposed to be good for 750+hp, and I will exceed that especially when the high internal power consumption of a blower motor is considered. OTOH the setup is very low revving, and I am under the impression that a big part of the load on rods is from revs.

Any experiences/opinions will be welcome.

Thanks.

Rich Krause

The Big Show

I personally would be a bit skeptical. You have ruled out revs but your cylinder pressure is going to have a dramatic effect. If I am spending the coin to make 1000+ hp, I'm not going to skimp on any section of the bottom end.

By the way, if I wasn't revvin' high I would be looking more for strength than weight.

Mindgame

I didn't see a mention of any concern over weight. To me, the man's concerns are in the right place but maybe I missed something?

I hate to keep bring Mr HP up but he's inspired me to do alot of reading so what the hell.... he suggested I read a book titled, Maximum Boost, which is an excellent read by the way.
The author of this book, Corky Bell, says that there are two loads on a connecting rod, 'inertial' and 'power' or 'compressive'. In summary Mr. Bell goes on to explain that 'inertial' loads (tensile loads) are the most damaging, in that they induce fatigue failure and that they are the primary focus of connecting rod design.

From that I gather that a low revving motor can probably get by with a little less expensive rod, even with higher 'compressive loads'.
All theory aside, we have guys round here running slightly less than billet rods. One guy in particular running a BDS blown small block has been running a set of Manley h-beams for 2 seasons without any problems. He's putting about 700 hp to the rear wheels too. So, in my opinion, you have enough rod to do what you wanna do.

-Mindgame

rskrause

That is kinda what I have been thinking. My understanding is similar - that inertial load is the big issue and that with my low revving setup I may be ok. I currently have >700rwhp and am planning on 900-1000 for the new setup though. Of course, it's only for 9-10 seconds at a time!

Thanks to you and "Big Show" for your opinions. I look forward to hearing some more.

Rich Krause

89ProchargedROC

I know of SS/O motors that were using eagle h-beam rods with ARP 220psi bolts and made over 1300hp and never had a problem FWIW

My one friend ran Eagle h-beam rods in his 900hp spray 406 that he shifted @ 8000rpm and he never had a problem with the rod.....now if you wanna talk about the 5 year old rod bolts he never changed well

I think you'll be fine with the rods ya got

Ai

Yeh.. tensile loads will eat em up.. cup motors break carillo h-beams all the time, but theyre turning over 9 grand...

put em in a turbo/blower car and theyll last fo-ev-a...well.. not really, but you get the picture

I havent had personal experience with oliver stuff, but the buddies that have had countless sets of them, all complain about quality control & breakage & stick to carillo now.

Carillo.. Caa-rilllll-ohhh... it just sounds nice .

I've got some carillo's and cams out of some cup cars if you want, ... they make killer paperweights lol =P

I think the eagle's would probably handle what youre doing, but if you want something better, that should last longer, and isnt made in china.. i'd buy carillo's.

http://www.carrilloind.com

Jason Short

Rich, in my opinion I would just go with the Oliver billet (or Carillo)rods....the extra money is worth the extra insurance, plus I assume you will still be using a 5.7" length. That is alot of power...even though a cheaper rocd *may* hold up to that kind of treatment, just the questioning of it would make me spend the extra money for the best rod.

Are you going with a larger blower next year as well?

Just my thoughts
Jason

The Big Show

"I didn't see a mention of any concern over weight. To me, the man's concerns are in the right place but maybe I missed something?"

Thats why I edited my initial post. Rich was lookin' for opinions so that was just mine. There are certain parts of the motor where I look for deals and try and skimp where I can but when you start reaching the higher hp levels, skimping only comes in "deals" not quality of parts. I think the pro mod rods are VERY good rods and wouldn't hesitate to use them.....but when we start talking about near 1000 hp I really don't care what anyone else is doing or has done. I like piece of mind and knowing I put a part in my motor that I had a question about wouldn't set right with me. Matter of fact, everytime I went to push on the 'go' pedal I would be worried that I might be in that low percentage of people who weren't so fortunate.

That being said, thats why I made the comments I did. I myself am using Carrillo rods and I won't be making 1K hp. I am all for reading but I prefer to see real world results so you can see the application of what you read...

rskrause

Well now I'm confused! But keep the opinions coming

Rich Krause

89ProchargedROC

Well, in a low rev setup as long as you have good rod bolts i've never heard of ANY cheap/expensive h-beam breaking....i've heard of rod bolts breaking and taking out the motors obviously but i've never heard of a rod asking dumping

Thats why i feel the h-beam rods whether they are carillo or carillow clones (eagle/CAT/etc) are a deal for the money. Put a good bolt in the rod and you shouldn't have to worry about it

TAYLORMADE

Piston wieght is a big factor in how much power a rod will withstand! If you call oliver they don't really rate their rod by hp. A rod will pull apart long before it will bend or crush. If you have a real light piston, pin, and ring package it will severly up the power level the rod can with stand. A rod should be rated by the recipacating weight and the rpm which it is ran. Most all manufactures will tell you this. I use some extremely light piston and pin packages on circle track engines which allows me to use a rod rated way lower than the power we're making. I use 297 gram pistons and 87gram pins this allows me to use a crower sportsman rod rated for 500hp at 7000 rpm but have not had any failures at the 640 hp at 8500 rpm (30 to 40 lap races, 15 to 20 races between freshenings) Have had a set in my personal motor for 6 years and have passed mag everytime and still haven't needed any resizing yet.
One note becareful on wrist pins, Ive seen alot of engines that broke and blamed on rod failure when the real problem was do to pin flex. If the pin is to thin it will flex enuff to lock the piston or rod to it and will snap the small end of the rod lookig like the rod broke. When useing large doses of boost or nytrous the pin need to be alot thickers. Talk to you're piston manufacturer. The last high nytrous engine i did (350hp kit) needed at .180 wall tool steel pin.
Most pin clearances are around .0008 to .0011 so if the pin bowes even alittle it can lock up in the piston or pin.

89ProchargedROC

very good info

rskrause

"taylormade": thanks for the info. In my case I need a strong (which to some extent = heavy) piston to stand up to boost + nitrous. The piston I plan to use is a JE "Extreme Duty" that weighs ~480gms minus the ring set. Your point about the wrist pin is one I hadn't thought of. I will be sure to get a stout pin whichever rods I end up going with. I am leaning toward reusing my Lunati rods with new bolts.

Rich Krause

The Big Show

That was some good info man. My builder is a stickler in a few key areas where he won't give me any decisions. Just a few are wristpins, valves and springs.

Outstanding rodbolts were a given in this situation so I didn't even think that needed to be addressed.

Those are some heavy pistons Rich...

TAYLORMADE

RSKRAUSE
Do you have pistons already? J.E. is a fine piston but you should look into C.P. pistons they are made be Calvert. The three bothers made JE what they are today. They all left and started CP about 4years ago. They do alot of cup and high end pistons. JE was 79.00 a piston for customs and CP was 79.50 but they offered free pin fit(40.00 value). You should look at customs you'll get alot lighter and stronger piston helping you're rod situation out.
Also srp pistons use a F2 shirt design, a JE piston uses a F4 shirt their is a fair amount of power difference between the two. I used to always use the F6 design on Custon JE's it's alot more stable in the bore and makes alot better power than the F4. There is alot of different shirt designs that are better in certain apps and not in others.
CP piston all come with the accumulator between the top and 2nd rind which dampens the pulses between the rings that will unload the top ring causeing ring flutter and lose power. The acuumulator is standar on CP's but you pay more on JE's.
Any decent machine shop or engine builder will no about CP pistons although most indivuals don't.
I believe you shouldn't have any problems with the mod rod as your rpm are extremely low.
CP should be able to build a piston around 410 grams assuming it's a flat top w a 5.85 rod or longer but I'll bet you have 5.7 and a dish.