Just start it simple, are IRL car. rods strong enough for a small block build???

And if it would work, any input on taking the K1 340 4.125 2.00 Rod Journal and offset it a hair more or a crank in that area??

I know the eagle honda rods are not up for the job, Ive heard of a low bobweight build, that tossed a rod bolt at about 7500 and spit its guts????

Thanks....

Depends on intended horsepower and rpm. What are the goals of this fantasy build?

Fantasy my azz, Im asking for the specific of finding the limits on such parts. Mainly the rods and crank.

But since you asked, ive several X blocks and a few sets of new IRL rods and short of a billet crank which is beyond my needs im ust trying to find the limits on the rods and if its possible to grind the crank down. I would like to spray it but if not possible just run a good bit more comp.

How much power are you looking to make??

You have to figure these rods can handle 900 hp for 4 hours straight no problem. I called Carrillo once on the rods and IIRC they told me they would handle upwards of 1200....

Those motors have extremly short strokes but the bores are about the same as our SB motors. The pistons are way lighter than anything we ever dream of useing also. Exact strokes and bob weights are gonnna be top secret but if you could find them you could calculate how much load they would see. Just off the top of my head I would figure they are gonna have about 1/2 your stroke and an off the shelf piston for your motor is gonna weight twice what the IRL piston weighs so it would be more stress at the same HP. Now if you are talking about a NASCAR rod with IRL journals, they are desighned a little different.

I guess the rods are not the problem, if you rev lower than the Nascar engines, but the crank gets skinny with no overlap between rod/main journals. Torsional vibrations can then crack the crank. Better use a good damper, my
If you go for it; grind the journals with large smooth radius, and get it nitride hardened after the grinding.

Yep the nascar IRL rods, just rtying to find a use for them. Ive 3 new sets and so I could sorta build around a good rod if they were worth a crap.

Might go a shorter stroke, 4.00 and then not have to make the crank wonder.

Ive seen billet 3.79 cranks for these rods but dont feel its needed.

I mentioned the one that blew up, but it was a stroker with more or less the eagle honda rods and im told a rod bolt broke.

However it was a good spinner as if I remember right it was on the lower end of stroker bobweights.

Just trying to do see if its possible, I like different.

Yes, it could work OK. If you lower the rpms with the same ratio as you increase the stroke, + some margin, and use a heavier damper, it could work OK.
I also like different! Just ground my old Mopar 3,75 LA crank to accept 2,1" SBC 6,2" rods, for an R3 9,1" alu block, with 2. hand 4.130" 1,062 C/H pistons; cheap fun!!

if inrested i've got aset of 6.2 carrillo rods w/ 1.88 pin size w/.940 width & .780 rist pin size, these have have the ar800 3/8 bolts, edm oiling, $350 +freight jg309@hotmail.com, 618-806-1564 thanks

the fast hemi Superstock engines use the Honda rod journal size. 9800 RPM and a much heavier piston/pin than a small block.

I thought of a similar build before I bought my K1 and Childs Rods. I like different too, but I was scared of having such an exotic engine combo, and if a failure happened Id have to start all over with more exotic stuff. Unless a guy could get 10 or more rods, and just order a couple extra pistons. The build shouldnt be an issue, I had everything at one time figured out, and on notes, but as soon as my current 408 got started I just threw it all away. I also was gonna use the carr rods, and the small honda journal.



Kasey

guy's have a 362cu, with 1.88 rods about 9000rpm, was building a 397cu xr2,p7 about 900hp,9-10500rpm till got sick, these rods are great jg309

THANKS! for the input....

Thanks for the input, didnt mean to sound like a smartazz at first, just needed to know if it was possible and can go from there.

Im thining the bobweight was in the lower 1700-s but let me check withthe guy before I get tossed for that number.

1700 sounds heavy maybe? you thinking mid 1500's?

The newer nascar stuff is in the 1440-1480 range.

The older 2.000 stuff is any where from 1700-low 1800....

My engine has a 1467 bob weight

There are also a few in between there as well.

So to be safe nascar stuff can be from low 1400- low 1800.....

makes you wonder just how low you could go with alum rods instead of steel... but thats another thread.

IIRC it was in the 1600-s I really dind want to toss a low number out because if was wrong/unrealistic I didnt need 40 posts tellimg me so.

The dude that did its a member here, maybe he will share that combo I refered to.

I really like RPM, and turn strokers past what most do and ive a good many parts that would make this a solid build.....

All the rod sets have the small pin which is edm oiled, I imagine some high end pins would be in order, and wouldnt a 6 inch rod and small pin keep things way off the rings????

One the pin note, when I put together the hughes 426 kit, the ad said small dia lighweight pins...both std pins (what ross uses) and the smaller pin were dead on on the gram scale...which really means nothing.

Id like to do this with an X block base and the nice B1BA heads I got from Kas. And im thinking with the heads maxed out I can have a good solid build but at the same time the heads will keep me limited to a certain power level within specs as not to over run the rest of the parts.

I really want to run a std 250 shot so maybe some gas ported, small pin pistons.

Again, thanks for the input....and if anyone has firsthand info on this idea....please stepup, good or bad....id rather hear hey stupid it wont work that way vs, id look at this area, as I may not look and it might cost me money.

The only problem I can think of is a relatively small bearing surface for a power adder