Inliners International Forums General Discussion Hi Performance stock rods vs. turbo application

A quick question re: the use of the stock rods with a turbo. Would this be realistic in a street application at perhaps around 5000 to 5500 rpm with proper pistons/compression ? I have just gotten Santucci's book and used the search also but can't seem to fine a specific answer to this one. Thanks in advance.... Fred

For what engine are we discussing? How much boost?

Ooops, 'sorry! 292, 10-14 lbs.(?) At this point I'm just trying to get a feel for what is practical for a very, very good street engine and I've liked the prospect of the turbo thus far. On the other hand, the last time I was involved in a perf. 292 was when I worked in my cousin's Auto machine shop back in '74. Much has changed. My heads fairly spinning from this new learning curve!

Ok, that level of boost and power your seeking may be beyond the capability of the stock rods for long term reliability, so you may want to consider something better.

Thanks CNC, These sanity checks are no doubt a bit tedious for you guys who are well versed but are nothing short of invaluable to guys like myself who are digging thru reams of info. in our own quests. Thanks again! Fred

Sure, no problem. The stock rods will no doubt handle some level of boost up to a point, but I don't want to be the one to find out where the limitation is. Some of these parts are not that easy to find and having a piece of mind that your not on the ragged edge is worth something.

I have stock reconditioned and opened rods with around studs in them but I will probably only be 6 psi max on my 292

I am not much of super/turbo-charger kind of guy . . . but I am curious as to why one would choose more boost over higher static compression (less dish - smaller chamber) in a street application? Aren't they means to the same end?

In my mind at some point the boost pressure runs into the restriction of the intake port and valve CFM limits and VE stops going further north of 110 or 120% (whatever the limit) no?

Thanks for getting back gents, and sorry for the delayed response. Touching on all three responses, I'd first say, in hindsight, that I probably over estimated the boost level I'd need for a decent street performer. At the same time I did take note of someone else's comment about boost being addictive. I've only owned one turbo'd car in my life and that not so little afterburner effect has stayed with me all this time.
As to the higher static comp. I'm not against that in any way but it's always there putting ooomph against the bottom end whereas the boost comes rolling on only when needed. So that's kind of my train of thought at the moment.
While on the subject of boost here's an interesting tidbit. I have here a Paxton blower given to me by an old time drag racer from Long Island NY back in the 60's-70's. I have pics but can't post them (files too big/poor computer skills) which is too bad. He told me it came off of a 6 cyl. Corvette. It has the mount bracket/idler still on it and a mixed bag of pulleys plus two carb hats and 'T' for the plumbing. The bearings are shot. It's ser# is VR-58-E-2800531. There's also what appears to be a press. regulator also with the Paxton name on it. A warning tag on it says the warranty is void above 5 lbs. boost. If the '58' in the number is the year this seems like it might be a mega-find as coolness goes. 'Your collective thoughts?

some quick web searches suggest that the OEM application was for a Ford y-block in a '58 T-bird. But according to this site they were kitted for the aftermarket as well:
superchargerhelp.com

Thanks stock49, that was a great read! I guess my guy might have been right about the Corvette appl. based on this. I seem to recall the 6 cyl vettes used two sidedrafts and hence the two carb. hats I have with the unit (?). I'ts kind of a moot point now at any rate but it would make a slick 'period correct' install on something. 'Fun read on a dreary day...thanks again! Fred

3 sidedraft carbs were used on the 6 cylinder corvettes.

Oh well, there goes that 'the guy told me' story for the second time (chuckle).

A stock rod that has been rebuilt with ARP hardware and a modern light piston , should have no problem in the 5-5500 rpm range with boost. Although 14-15 psi may be pushing it. 5-10 should not be a problem.

Thanks tlowe. 'Heartening info. indeed. I was a dope to spit out such a high boost# initially in the first place. I'm just looking to get something like 300-350hp (street) without going to the "ragged edge" that CNC referred to, which according to a prior thread is attainable with a 292 even N/A. Still, I like the 'on demand' power of boost. I wonder if the the VR-58 Paxton I'd mentioned earlier (5 lbs. boost) might be brought into the equation since while basically a 'core' is still here for the price of rehab. (?) 'Collective thoughts?