Some may already know about this eBay seller but he has some of the best used NASCAR engine and engine related parts around at VERY affordable prices. His eBay name is hindel15. Example: 1 or 2 race old Pankl or Carrillo con rod set of eight for $85. May be a good source for LSR racers on a tight budget but still want the best.
John
Hi John,
While I agree with you that some used NASCAR "cast off parts" can be a great value, I disagree with the idea that those parts might be the "best". After having spent a lot of time in NASCAR engine shops, everyone needs to know that typically these rods are manufactured for "maximum lightness", and therefore have a very short "reliable service interval". Probably something like 1 million cycles, perhaps a bit more.
After inspections and with a set of NEW rod bolts, these types of parts could be used,
AS LONG AS THE USER REALIZES THE INHERENT RISK. I don't presume to make decisions for racers, I'm at the point in my career where I merely remind racers of the math or the science that
SHOULD be involved in their decision making process.
I'm adding in something I posted on another site, Vintage Racing Online. Read on about one racer's experience re-using older Carrillo rods, without cycle life knowledge and without any testing or inspections . . . . . . . .Once again, down the same rabbit hole . . . . . . part 2 . . . . . Well, I confess: I'm getting tired of a being a "racing engine coroner". . . "It's like deja vu, all over again." Yogi Berra
No photos of these bits either, a courtesy to the owner. However I know the owner is a "reader", and perhaps may post photos of the "carnage".
This past Monday, a third party brought by the shards of one of the latest BMC 'A' series engine failures. It wasn't a typical failure, as it was a breakage involving "premium quality parts". The failure was a broken, aftermarket "Carrillo style", H beam connecting rod. I think it was in fact, an actual Carrillo (or CP Products now) produced part. Atypically, the rod broke just above what rod manufacturers call the "shoulder" of the rod. This area is just above the "big end", where the beam of the rod narrows heading up to the pin end. This narrowing is required for the rod's big end to clear the bottom of the cylinder walls as the crankshaft rotates. Needless to say, when the rod separated into 2 pieces at high rpm, BAD THINGS happened as a result! The remains were in at least 4 large pieces, and many smaller shards.
The question became: "It's a Carrillo rod, how could this happen? ? ? ?"Well, let's do a bit of thinking about this question, and this failure . . . . . .
It seems that there is a presumption that, somehow, premium quality aftermarket parts are "indestructible". This is, of course, untrue. But after racers pay out their "big bucks", however, most racers would like to think: That item is "forever".
You are not buying a "diamond"! ! ! (And despite what De Beers claims, even diamonds are not forever . . . .)OK, OK, I'll get back to reality then . . . . .
A/ H beam connecting rods are usually used because they can be made LIGHTER than I beam connecting rods.
It's a fact that the rod set in question was made for maximum lightness, ie: minimum weight. Premium quality material and premium quality 5/16" rod bolts were used. The ONLY reason to do that is a quest for minimum weight. There can be "advantages" to minimum weight. There are also "disadvantages" . . . .
2/ Note that lighter components are usually LESS durable than heavier parts.
These Carrillo rods are sub 490 gram total weight each. Compare that to the ultra-heavy stock BMC rods weighing 680 grams each, using 3/8" rod bolts. I'm not going to cover this topic again. Go back and re-read reply #21 to this thread. It concerns materials science and reliability.
d/ And there are "other" factors.
I have seen this type of failure previously, on several occasions, for several reasons:
1/ The previously mentioned durability cycle/lifespan reasons.
2/ Unknown inclusions (defects) in the beam of the con rod. Quality manufacturers x-ray every rough blank con rod, and reject those with this type of defect. Lesser manufacturers may not do the same. And there can be "mistakes", despite the best intentions.
3/ Mechanical interference: H beam rods are wider than their I beam counterparts. I have seen engines where inadequate clearance existed between the "shoulder" of an H beam connecting rod and the bottom of the cylinder. Even slight contact between the shoulder of an H beam con rod and a cylinder with inadequate clearance, results in disaster.
So what's the answer?Well, if you are racing for money or prestige, the lightest weight (mass) components can give you an advantage. This is merely the math, and professional racers accept the risk and the cost of periodically replacing components. This is why ebay has countless "slightly used, but cast off" components for sale. Professional teams use these components for a set number of miles or hours, then discard them. The idea is to prevent a component failure while perhaps leading a race. Statistical analysis proves this to be a sound methodology for success, in spite of increased cost.
But what if I'm racing for "fun"?If that is the case, then your decision criteria are probably different. The final decision about component weight and the resulting reliability gets to be made by those whose "checkbook does the talking". The decision is: "unlimited" component life Vs. the perceived advantage of light components.
Caveat emptor!
