what engines have rods longer than 6.625?

I was wanting to know which engines came with rods longer than 6 5/8" or 6.625"?

thanks,

Steve
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wild guess: every engine made before 1949

or do you mean "modern" engines?

 

65-67 olds 400 6.996
68-69 olds 400 6.736

65+67 olds 425 6.996
68-76 olds 455 6.735

413 chrysler 6.760
440 chrysler 6.760

 

olds 455 has big ones.
http://www.strokerengine.com/RodStroke.html
Jegs lists the length on their site, example
http://www.jegs.com/i/Eagle/356/CRS673503D/10002/-1?parentProductId=744628

 

Flathead Ford... And the ones that fit this crank...

 

7" K1's in my 509" Cadillac. But they can pretty much make you whatever
you want... http://www.campbellenterprises.com/K1-Technologies/k1technologies-connecting-rods-crankshafts.htm

Originally had the 7" Olds rods mentioned above.

 

7" in GMC 302

 

392 Hemi @ 6.95"

Several 'long' rods for the NASCAR 426.

.

 

Krooser you got it

I think this just might be the longest connecting rod by far.


http://people.bath.ac.uk/ccsshb/12cyl/


,

 

Thanks for the replies everyone.
With that said,
would you guys also know the other dimensions of the 65-67 Olds and the 392 rods?

pin dia?
rod journal size?
big end width?

Also, I think all these rods are forgings too?

I'm designing a very small de stroked Pontiac and would like to use an exisiting rod or piston so I do not have to to buy both as custom items to keep costs under control. By using a longer rod than the stock Pontiac ( 6.625" ) with the short stroke, I will be able to keep the piston pin height shorter for a lighter reciprocating weight.

Steve
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Google 442.com and go the the Olds FAQ. The info you need is there.

 

Also less rod angularity - what a great idea.

 

Useless for what you're doing but an early jeep flatty has a 9.25" rod.

 

I told my wife I had the longest connecting rod...

 

You've probably already seen this...
http://www.wallaceracing.com/enginetheory.htm

 

within post number 10,

you have said that you want the longest rod because it will also make the overall recriprocating weight less in the overall computation.

well,
not really,

because in normal rod/piston/BOBWEIGHT computations,
unless this is an odd cylinder engine ,
when you do the computation on bob weight,
the weight of the " small end " of conn rod is considered "recriprocating" ,
which would also be then added to the combined weight of the complete piston/rings /wrist pin...

the large end is considered "rotating" which is not recriprocating....

what weighs LESS...?

the added aluminum material in a longer piston......?

or

the weight of the extra length within longer rod.....?



your thoughts are correct,...but a bit mis-led...or you have a mis-understanding about how an engine/crank assy is balanced.

but there is a gain at some point in being able to have piston dwell at tdc and bdc with the longer rod/short piston...
but there is also a gain with a faster accelerating short rod/ long piston assy....
.....(but this is a consideration within a race engine) ......

you just have to decide which one that you want.




oh by the way,


the longest rod that I know of that comes out of a kinda popular/well known engine is out of a G M C straight six cylinder OHV......

 

Can you give out any specs on the destroke poncho?

 

Yeah, and she probably said length doesn't matter.

Seriously, I am always impressed by the breadth of knowledge available here on the HAMB. The actual tech answers and the links are amazing.

 

I'm gonna take a shot in the dark here and say you're going to destroke a 326 down to a 295ci alky injected roundy round motor? Or will it be a 389 down to 350ci? I have no clue, I just like guessing

 

Ford 6 cyl has 6.800

 

394 Olds 7.050 rod length, 2.499 rod journal, 2.990 main. this is from memory which sometimes is not to good.

 

Model A/B Ford: 7.5"

You can get custom BBC rods that are 7"+ long.

 

Pontiac and Olds have same wrist pin if your wanting to use a shelf piston ,
the 7" olds rods can be had used for $40 -50 a set . crank is 2.5
a 7.1 BBC H beam style can be had cheap too , you go to a little smaller pin .990 , crank is 2.2 .

 

I have a 1960 389 SD forging that I bought on ebay. It has been modifed considerably. What it was modified for, I do not know. the crank snout was tapered down to a point, the mains were grooved and it was detroked 1/2", plus the rods are larger than Pontiac size ( forgot the measurement on rod jounal and the crank is in the crank shop ).
What I am building is a very small 4cylinder engine of around 145 cu in. It has potential to be used in a number of things but, initially would be used for a street/mileage combo and probably be turbocharged.
Because the rod journals are oversize I have the option of making a final decision on stroke and the option on rod journal size too.
As I mentioned earlier, if I can find a production rod then I would just need to order custom pistons to finish the shortblock.
Since yesterday, I've learned the '65-'67 Olds rod is 7" long and has a .980 pin ( same as Pontiac ). I still do not know if these rods are forgings and still do not know the big end width or journal size. I was unable to find this info on the 442 site.
Steve
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Good point. I do understand reciprocating weights but, did not word my post properly. Thanks for adding.


Now, after seeing the last few posts, it appears the Olds rod may not work for me with its large rod journal.

Now, I wonder about the rest of the dimensions of the 392 rod, or see about an inexpensive set of 'h' beams.
I would only need 5 or 6 rods ( I like to have a spare of 2 of everything I build ). Maybe I can find a partial set from an engine that expired but, first, I need to look at the rest of my options.

 

as far as rod jounal size, it is yet to be determined as i can weld or machine it to different sizes.

Do you know the rod journal sizes of those early Olds? 392? or GMC or others?

Steve
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You're chopping up that 389 block for a turbo 4 banger? SWEET! Why the hell is the crank snout tapered that much?

 

I've made no mention of what block I am using, just the crank. I do not know why the snout was machined that way. I have since had the snoutn welded and machined back to stock specs plus had a second keyway machined incase I ever choose to use a roots blower with it.

Steve


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Slant six Dodge has three different lengths. I don't know the 170 inch just offhand, but the 225 uses a rod of about 6.7", and the 198 uses one of about 7". There are aftermarket rods available in the 7" length. You can do a search at slantsix.org and find the dimensions you need.

Roger

 

Good call, and they're forged too...I believe the cranks to be the same across the board for slant 6's, which means the 170 rods will likely be longer then the 198 ones...