+1. You are wasting your time and money on this one. Oh well, if he wants to do it, let him try. When it doesn't work out in his favor, we can all laugh and say: "we tried to tellyou."

 

Hey Tyler.... See my signature.... (the last line in particular)

 

Look dude, Im not trying to tell you what can and can't be done here. Nor am I being a"coulo" (aka: *** in english)I know what it is like to wantto have something different. I have a 4.3 ChevyV6in my Jeep. Why didn't I build the stock engine, or why didn't I put in a 350? Because I wanted todo somethingdifferent. I built it up the way I wanted it, and I am 100% happy with how it turned out. Maybe we are misunderstanding your goal here. If your goal is to have a heavy engine that has no power and won't wind up worth a flip, then you will reach your goal. Im not trying to tell that you cannot do it. With a custom crank and pistons, you probably can, but the results will be hurting your power really badly, and I can't see why anybody in their right mind would want an engine like you are describing. 99% of peoplecannot tell the difference in a 351 block and a 289 block just by looking at them (hell, the valve covers are the same), and 90% of the poeple who can, cant distinguish a 351W from a 351C. Frankly, nobody is going to care how "custom" something is unless it runs extremly well, and the engine you are describing won't. Im not being harsh, just stating the facts. It would be way cooler to build a Boss engine of some sort with Cleveland heads on a 302 based block. Heck, Edelbrock even makes an intake to do it with now. Call me an *** if you want, but when (and I'll admit this is going to be harsh) you're at the light or lined up next to a buddy at the track, you'll be the dumb*** who spend so much time and money on a custom engine that runs like poo. No offense intended, but I hate to see somebody put so much work into a lost cause.

 

I wasnearly 100%joking about the Coulo thing Tyler! (Although it is impolite to talk about a person in the third party when they are standing right there!!)

In any case I was just throwing this up as an idea and as an issue sure to attract attention and generate controversy, (the forum was really slow when I posted this!), but stillan idea, (begging yours and others pardon),that Ibelieve if properly executed couldproduce a viable and efficient powerplant... Actual execution may well be a difficult thing to pull off, butthe theory of operation is soundenough toshame any 289,302 or 351based NA and/or unjuicedengine represented on this forum, yours included... In other words, it is my opinion that he only "performance handicap" that this engine would suffer would be a result of it's small displacement, which would be overcome by the blower...

If rod length and piston compression height would be an issue then a 302 or even more realistically a 331 stroke might be more in line with reality, a small concession to my overall theory though, don't you think....

 

Oh, well Im sorry... Its hard to catch sarcasm through typing. Don't take offense to anything I said. Please. I (as well as most others)wasjust trying to logically show you why it is impractical. I agree that with a longer stroke crank (you mentioned a 331) it would be better, but the real killer here is the roating mass of the heavy rods/pistons. Now if you had some lightweightaluminum rods.... that might be a different story.

 

What part(s) of a connecting rod are the heaviest? I say the ends by far!

My educated guess says that adding an inch of length to a good quality I beam or H beam rod will effect its weight very,very little in relative terms (ie total grams and more so grams per inch of rod).... Thiscombined with the reduced lateral rod movement (and therefore slower also)generatedin a short stroke enginelessens the effect of these slightly heavier rods to be a moot issue.

IMO heavier rods is a non issue, but I do grant the point that light pistons are important making a 331 (3.25") stroke a much more practical build.

And no offense taken, just having a little fun, I have a problem with intentionally pushing peoples buttons a little,, but all in good humor!!

 

The extra rotating mass is there. When you're talking about weighing a rotating mass in grams, an extra inch of solid forged rod is going to make a big difference. I'm sure balancing the thing would be a nightmare in itself. And whether lateral or vertical movement, it still has to move.

You still haven't really come up with a good explanation why you'd want to use rods that long on such a relatively short stroke. There is no benefit.

 

My examination of Eagle rods on Summit Racing has demonstrated that rod weight is not influenced much (or at all!) by legnth or even type, however,the HP rating of the rod seems to make a big difference in weight....

If I were to concede that a 3.25 stroke makes a lot more sense, (which I doin consideration ofour conversation here!), then a commonly available (and commonly used) 6.2" (or so) rod would do...

It is my opinion that the 351 block has advantages, strength with affordable pricingcombined with what I still consider as an advantage in concern to the long rod, piston side loading etc...

And besides, if I had not mentioned anything controversial, we would have been done talking some time ago...

 

A 6.2" rod with a 3.25" stroke puts you right where the 302 SBC used in Trans-Am racing and the early Z28´s were. Seems like a good enough precedent to me, and I don´t see any real benefit in going still higher with that ratio. And then you've those extra 30 - 45 extra cubic inches . . .


Norm

 

I am glad we are coming to a point where things are coming together,,,, because there is no way I can argue with you Norm! I regard you as the ultimate performance authority in this section... (sorry everyone else!)