rmbuilder

I have personally used Carrillo Rods without a component related (or cycle test) failure since 1969 in Trans Am, Can Am, circle track, and marine applications. Here is a tech paper regarding their approach to reciprocating mass and connecting rods. I do not believe there is any advantage (or disadvantage) to be gained by the use of Ti in this application.
http://www.carrilloind.com/tech_archives5.html
Ti is much more relevant where acceleration is at a premium, which is not the case here.
Hope this helps,
Bob

Mbam

Don't take this wrong, but do the math.

90 x 5 x 8 seconds = 1 hour

To me that is just barely off the dyno.

As pointed out by Patriyacht, the limiting factor to longevity is the valve train. It might very well be that titanium rods would work great, but what is the real benefit? As Bob pointed out acceleration is not an issue. Better to put some $$ aside for a lifter (roller) change every 50 - 75 hours and springs every other set of lifters. This assumes that you spend most of your time cruising at part throttle. Even though if 850 HP is your target a good set of heads and a flat hydraulic cam will do the job and last much longer. With a good pan, oil system and conventional premium components the bottom end should be OK for 400 hrs no problem.

I will add that I do not personally have any experience with ti rods.

Puder yu ready tp move south yet?

mcollinstn

A 1000hp blown bigblock will NOT need to turn 7200 rpm. No reason to spin it that hard.

You'll see 1000hp at less than 6500rpm, and if you are running an optimized parts combination, you can see 1000hp on a 550" motor at less than 6000rpm and less than 9 pounds of boost.

You seem to be concerned about the life of the rods/bottom end, but you are going to run it silly by spinning it at 7200?

You have mentioned that you want input from marine sources, but haven't said whether this is a marine application. If you are talking about an automotive application with 7200 rpm shift points, then that makes far more sense than a marine application with a WOT rpm of 7200.

Just trying to understand..

Little Tommy

exshaust valves and roller tappets also valve springs are your weakness in motors>

Blownolds

Thanks to all who have offered input so far.

Mcollinstin, your hunch is correct, and is why I have been hesitant to say exactly what the application is, since this is a marine board. The application I am considering them for is indeed an automotive application. It is a street-strip drag application in a '40-Ford. Since aluminum rods are not really suitable for street due to low cycle life (though they can handle thousands of horsepower), they would not be a good choice. I expect to place 2000 hard miles on the engine annually and because of that type of use as well as the fact that the engine will be run in drags, I am trying to research Ti-rods to see if they will hold up to long cycle lifes. The weight savings of Ti rods over steel rods should be obvious in any engine used for acceleration as well as any engine that has a little weaker main webbing. I figured there would certainly have been some offshore powerboats that have used the Ti-rods, either successfully or unsuccessfully that could give me input from actual experience with those. Anybody here?

Strip Poker 388

iTrader: (6)

Sounds like your in the oldies type drag racing. There is a co. called Good vibrations in Ca. They do a lot of blown nostalgia stuff. There in National dragster. also try Marv at The Blower Shop. He's up on the blower stuff.
We ran some Tit rods in a mud drag truck for a while . motor was real strong and raped quick .ran it about 3 years and a rod let go Or could of been the bolts.we where turning it 8800 though.Changed to the steel crower rod then.

Depends on which crank you go with . The tit rods are pretty lite. We were at daytona for Industry week .before the daytona 500 and one of the Manuf .had a Titanium crank . Nascar outlawed it not cost effective $10.000 was the estimated price WD. bet it wound up in the Sprint Cars World of out outlaws .Could you imagine a little sbc 400 something ci with a 25 lbs crank.
Crower is what we run ,they are usually higher that everybody . They have a light weight bill-it 4340 rod that might be something to consider or the maxi lite or just call the crower tech line you can ask for Dave Crower himself .Have your ducks inarow ,he's short with ya on the phone

http://crower.com/pdf/173.pdf

http://crower.com/misc/m_cat.shtml

I use to run theCrower 6 inch 4340 small block mid weight billet rod and put 13000 street miles and a bunch of NOS passes. the 358 dynoed at 540 hp on pump gas and we went as high as 475 hp of nitrous on it . The Crower rods and crank held up great . the bearings were always very good , even on detonation and burning pistons they never showed any flexing that would show up on the bearings.
For the price of the tit rods you can get 3 sets of the steel ones ,That is at the jobber price .

puder

in an automotive engien i'd think 1000hp shodul eb way easier. No worries abotu reversion and finiky low speed perforamcne spo you can run radical cams PLUS you can run way more oost becasue you aren;t running at 5000rpm for 45 minutes.

sombody wa stellign me the otehr day in a some kind of alchohal dragster they are runnign liek 46psi of boost. and making over 2000hp. SOmthing relaly silly granted that engien gest rebiult pretty often but still.

mcollinstn

Olds,

I do understand your figures better, now that I see they aren't marine figures.

Furthermore, if we are talking about OLDS motors, then your weak block issues can be partially offset by going with a custom crank with LOTS of mallory metal in it for a good internal balance. This does a better job of offsetting the balance issue AT THE SOURCE rather than on the ends. This spares a lot of the cyclic loading on the block itself. And that crank and a set of polished billet steel rods will cost a bunch less than Ti rods.

Not trying to talk you out of anything, just hate to see you trash a good block by running exotic parts beyond their fatigue cycle limits..

GeeterB

Has anyone used these in a marine motor and do they have benefits???

mcollinstn

Lighter valves ALWAYS will offer benefits, but ion the case of a BB Chevy, the other valvetrain components (lifters, pushrods, rockers) carry a significant amount of mass which must be controlled. Overhead Cam motors obviously benefit the most from valve mass reduction and see huge benefits from unltra light valves (they can run lighter springs due to the light valves and that helps too).

It's always a cost issue. If you could mfr the entire valvetrain out of ultralight components then you'd be really doing something, but you gotta balance it with the pocketbook.