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Aftermarket Connecting Rods?

DZZ71

DZZ71

"Living The 6.5 Dream"
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Location
Alberta,Canada
Does anyone know If there is after markerket connecting rods for the 6.5? I'm gonna be getting my other engine together soon and wondering whats out there.

Thanks, Chad
 
No idea, Chad, but I would think you can get shorter ones if you were looking to lower compression. It's a much better bet than shaving pistons, as you've already heard.

While you have things apart, are you putting the time in to balance the rotating assembly? It isn't all that hard, and it makes a big difference.
 
Yes sir, Im getting a scat crank and studs also, I plan on getting big power outta this one Im quite excited :)
 
only way i would lower compression is buying the 18:1 pistions, and i've never seen anything but oem rods for these.
 
Good article on Balancing your Rotating/reciprocating Assembly.

http://www.fordmuscle.com/archives/2008/04/RotatingAssembly/index.php

Yeah, it's a Ferd site, but a V8 is a V8. You've got some pretty competent racing mechanics up in your neck of the woods, or you could take the RA to a shop in Calgary or Edmonton. Phone around until you find somebody who knows what they're doing and who has the right equipment.

Failing that, you can do a reasonable job using a digital scale and swapping the reciprocating parts to get close, then by skirt shaving to get exact. Much better to do the rotating assembly while you're at it, though.
 
Hoyt572 said:
only way i would lower compression is buying the 18:1 pistions, and i've never seen anything but oem rods for these.
Click to expand...

Lowering the top of the piston by shaving and re-anodizing or re-stroking the assembly by using slightly shorter rods ... would seem to be a bit of a toss-up, there. It seems to me that either would work fine, but I sure wouldn't be comfy just shaving the pistons without re-anodizing or coating them (although I know others disagree with me on this... ).

You can add thicker cometic head gaskets to raise the deck too. Dropping compression lets one get a little more fuel/air in there without stressing things overly, so the benefit is worth the work, as I see it.
 
I was planning on shaving a new set of pistons with this new build but maybe a set of 18:1 pistons are more ideal for me. I wonder how much boost I could push through it having the 18:1s compared to just shaving 70tho off a set of stockers that puts me around 17:8? Hmmmm
 
I would def go with the 18:1 pistions, they aren't that much money, and they are made that way, your not shaving anything down and making it weaker. As far as boost i think with a set of head studs and lower end girdle, you could prolly run about 18psi
 
I was running 21 with my hx before I pushed out a head gasket. I'm shooting for around 25 psi with the lower compression. I just dont know if 18:1 pistons are enough. Unless I get thicker head gaskets to bring it down.
 
Here's the thing... if you can't get more fuel, then boost is just bragging. not power. The whole idea of dropping compression to 18:1 is so you can get the maximum fuel/air mix in there before the piston hits TDC (at which point, the pressure in there is REALLY high with a 21.5:1 ratio), It isn't the boost pressure that you need, it's the air mass (volume). Dropping the compression ratio allows the pressure at TDC in a high-fuel engine to be the same as with a normal engine at TDC

Once you get as much air as you need with max fuel, you have enough. More is just extra stress on the engine that you don't need.
 
yea i've never heard of a 6.5 running that kind of boost and stayin together, i've heard max usable boost is about 16psi and 18-20psi is just plain max boost.
 
Hoyt572 said:
yea i've never heard of a 6.5 running that kind of boost and stayin together, i've heard max usable boost is about 16psi and 18-20psi is just plain max boost.
Click to expand...

The usable boost was that with a gm series turbo? I'm really considering a compound set up for this one. I might just run my single HX35 for break in period while I decide how to fab the set up with intercooler. And Jifaire I know what you mean In your post. Kinda like how the ATT gives you more power at lower boost caues
It's pushing a higher volume of air into the engine compared
To the gm series. Im just just wanting to be safe incase I spike up to 25.... But then
Again I probley won't hit that with the compound set up.
 
You can hit 25psi easy, I can do it with a GM turbo or about that with an ATT. I have no way to regulate the ATT other than fuel so I guess the 6.5 fueling can support it.

Thats with all original engine. If it blows up I'll replace it. I dont do it all the time, only occasional, but 18-20psi is common enough for last 10-20k miles.

The ATT doesnt provide much more air at lower pressure. Slight density gains from lower IATs, less backpressure allows a bit more fresh air in the cylinder, and also power gains from it not being as parasitic.

A compound setup can be both efficient and boost higher
 
I dont think I have ever seen any modified connecting rods, just stock replacement.

I am no expert at compound turbos, never done it either. Just the basics of one small pair with one large, like sequential but different configuration. Something like the attached picture is what I had though about before. Location of components and where to tap into the exhaust manifold being completely up to the fabricator. I threw some turbo names on there that some people may already have or can get.

CompoundTurbos.jpg
 
i thought in a compound setup the idea was to have a larger turbo feeding a smaller turbo. or maybe it was the other way around?
 
chevyCowboy said:
i thought in a compound setup the idea was to have a larger turbo feeding a smaller turbo. or maybe it was the other way around?
Click to expand...

I think there are several ways people put them together. But in that drawing I made it does have a larger turbo feeding a smaller on on the compressor side. If you meant on the exhaust side I could see an argument for either way.
 
i was talking about the compressor side. i guess i meant like a much smaller turbo. i have never seen an att up close so i didnt really think of it as a bigger turbo, i thought it was ruffly the same just less restrictive
 
The ATT is larger, much so, although in a compound setup I would want it to have a larger output size since it is only 2.5", the same as the GMx. Ideally it would be the same size as the GMx inlet.
 
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