Connecting Rods

[JasonS]

The canted rod is also weaker.

 

[ODdave]

The canted rod is also weaker.

where dose this info come from? whats the fail rate of the 5.9 cummins rod? same cap design......

 

[JasonS]

where dose this info come from? whats the fail rate of the 5.9 cummins rod? same cap design......

This comes from Taylor's bible on ICE design.

 

[ODdave]

could you share this info? where is it weaker? Dose it produce a problem in the beam? (the ld's week knee) or is it refering to the journal and how the bearing rests in it? Or to the fact that bolts must be used?

 

[WillWagner]

That is incorrect. Most all of the modern HHP diesels have canteed rods and they are fracture split. Not just HHP, little 3.3L engines are like that too.

 

[ODdave]

The big end is canted like that for a couple of reasons. To allow for the largest possible big end bearing and to keep the dimensions of the block casting as narrow as possible. Nothing to do with ease of maintenence.

I do not know the spec on the 465 but on a 6bt the rod would NOT fit in the cylinder if the traditional rod design was used. There for the canted design is nessesary for assembly. It sounded like you where refering to the crank case walls. correct me if i am wrong.

 

[WillWagner]

Exactly. The big end bearing is as big as it can be due to the canted rod. The rod design allows for the lergest possible big end bearing to be used and keep the block casting as narrow as possible.

 

[ODdave]

the way you word it is confusing.

 

[ODdave]

anyone have info on the oliver / herc 2150 rods?

 

[ODdave]

not trying to add to the confusion, but this might be helpfull to the OP.
http://www.steelsoldiers.com/deuce/12029-multifuel-engine-life.html

 

[ALFA2]

Well, if multifuel is still the requirement, and mileage improvement is a good side effect, adding CNG injection and water injection will defiantly help in both of those areas. Better head gaskets, stronger studs/bolts, balanced assembly, bigger turbo, possibly an efficient intercooler air to water/laminova type, and better materials should definitely improve a good thing. There are several non computer driven systems available out there for adding a duel fuel CNG system to Diesel which retains all of the existing Diesel/multi fuel capacity as stock, and just adds the CNG on top of that as a separate subsystem, running up to 80% CNG 20% Diesel or other liquid fuel for the injector pump and injectors to be lubricated and functional. If you have the resources, the access and time necessary to do this and persist with this project, I believe you will get the desired results you are trying to achieve.

I hope this helps.

ALFA2

 

[Alredneck]

Interesting stuff, I havent tore a multi down yet but have a few lying round waiting. LDT and LDS motors. I was going to break it all down and compare all the parts between the two, but in my absence someone beat me to it I believe.

Is there enough room on these block to O-ring them instead of headgaskets?

I was also thinking beside the balancing of all the rotating assy, some power could possibly made through porting and polishing the heads, maybe some bigger valves. Also a more tubular exhaust manifold ( something like the cummins upgraded one ) might help flow the heat out and spin the turbo faster. Also a custom intake. I am working on a intake mod for my 250cummins I just turboed. I talk to alot of folks about this kinda stuff but my memory is getting worse. Gets some pics up so we can watch the progress!

 

[JasonS]

That is incorrect. Most all of the modern HHP diesels have canteed rods and they are fracture split. Not just HHP, little 3.3L engines are like that too.

Well, I can't personally argue either way; only relay what I have read. Taylor's book was clear in that the ONLY reason to cant the rod cap is to facilitate rod removal through the bore for a relatively large bearing diameter. That other engine mfg use a canted rod doesn't mean that it wasn't a compromise. If it were stronger, everyone would be using it. I strongly suggest that anyone interested in ICE design get a copy of Taylor's comprehensive two book set. It has a small section on multifuel engine design, too.

 

[JasonS]

could you share this info? where is it weaker? Dose it produce a problem in the beam? (the ld's week knee) or is it refering to the journal and how the bearing rests in it? Or to the fact that bolts must be used?

Dave,
I mispoke on the reference. It was actually Design and Applications in Diesel Engineering, edited by Sam Haddad and Neil Watson.

"The bearing cap joint should preferably be at 90 degrees to the rod axis as this offers more rigidity, better bearing support, lower cost and easeir fastenign than the oblique split design. This does, however, limit the crankpin to about 65% of the cylinder bore but this is usually adequate. ... The use of bolts and nuts for fastening the cap is preferred to setscrews because thier longer length reduces the stress range under dynamic loads. However, an oblique split cap design will require setscrews."

 

[rustystud]

Riktord, are you still working on this project ? I hope you haven't given up, as I think this is a great idea.
Rustystud.