cam specs?

Status
Not open for further replies.
I see we are a little out of sync on our posts.:smilewinkgrin:

after the new rods are weighed small end and big end with the bearing the piston and one ring set. Are also weighed and all parts are matched to the lightest one small end to small end etc with exception of the rings and bearings.

If you are replacing parts the old ones are no longer relevant.

Yes if you change rods to the newer type they May be very close as the parts are interchangeable by IH parts books but checking can't hurt.

One example is tim potters engine. It was machined in an attempt to lighten the reciprocating and rotating parts so the rods were modified so they are no longer IH spec weights. We are changing rods so all needs to be checked. Bad thing here is that the rod weight change made it necessary to lighten the crank excessively so it May be to light to balance with the new rods without adding mallory (carbide based heavy balance material) to the counter weights. That is when balancing can get pricey. You are not likely in that situation but I thought I would add the info.
 
The pistons and rods need to be apart to balance em, right? I still havent spoke with the machinist about running the isky cam. So, if hes already pressed the pins ill have a decision to make. Wheather to pay to do it over again and balance or, stick with the sealed power cam.
 
There still seems to be some confusion on the subject of balancing an engine - based on the repsonses from the participants (and my "reading" of the responses...).

I will attempt to state my "simplified" view:

robertk -- you can delete my post (or pm me and I will delete it) if you find it too far out of line...

Pistons --

if you look at the "bottom" of a piston, you should see two "raised metal bosses". The pistons should weigh the same amount. So, the "balancer" should weigh all the pistons. The piston that weighs the least amount will be set aside and all the others will have "metal" ground down from these bosses until all pistons are equal weight.

Rods ---

all the large ends (piston to crankshaft) and all the small ends (rod caps) should weigh the same amount.

This means not the complete rod, but the two separate pieces.

I do not know if the rod bolts / nuts are included -- I am not aware that the rod bearings are part of the calculation, either; as robertk stated... (I have very limited experience compared to robertk.)

crankshaft ---

this is a "gray area". You can have the crankshaft polished / balanced (assuming the skill level of the machinist is "up to it"). If you do this, you probably need the harmonic balancer and the flywheel also dynamically balanced -- based upon IH "dynamically" balancing assembled engines as an unit on the assembly line.

In my particular case (30 years ago), a new crankshaft was polished / balanced (the orignal crankshaft broke). "we" (mechanic and I) also made a decision to not use a harmonic balancer (stock for the engine), but to use a solid steel crankshaft pulley (from an "earlier" version of the engine) -- which was also balanced as part of the "package".

Hth to explain "things".
 
The 1800-5000 is the usable rpm range, or basically the camshaft's powerband. Peak hp will typically occur between 300 and 500rpms lower than the upper listed limit. So in this example peak hp shall be anywhere from 4500 to 4700rpms (per chassis dyno with a warmed up 345 and that cam).
Not putting anyone down, but just because someone builds "race" engines doesn't mean they'll automatically do everything to your "street" engine that they do to their "race" engine. Sometimes these people see this as "easy" money and will do only what is required unless instructed to do more.
Personal opinion, but as others have mentioned, if you're spending a fairly large sum of cash on the build, another $100-200 is worth it in my book for a smoother (probably longer living) engine.
IH sv v8's are externally balanced, and will require the flywheel/flexplate you plan on using. If it's a flywheel, get it resurfaced before balancing, if needed. Along with the front balancer hub/hamonic balancer and other internals listed in this thread (repeating robertc I know). Another item that some people don't look at is the pressure plate/clutch assembly on a manual trans vehicle. Most pressure plates aren't balanced to very tight specs. Example, my friend put a new clutch/pressure plate (big name brand) in his vette and it had a odd vibation. Pulled it back out, took it in and had it balanced (don't remember how far off it was, not much), now it's silk. Just more to think about.
On the term of balancing, another opinion I have is weight, or lack of it. I like light weight internals, something IH isn't know for. But you can have weight removed from various parts and places. The mallory metal isn't required when balancing an engine unless you add stroke (and a fair amount) to the crankshaft, or add weight to the pistons and/or connecting rods. So no worries there.

Picture of some connecting rods.

216114r21_top_309253c11_mod_bottom.jpg


Top connecting rod is a stock 216114r21. The bottom one is a lightened 309253c11. Both weighted roughly the same stock, 960g for the 216114r21 (stock) and 955g for the 309253c11 (stock). That's total weight, of the rods. The 309253c11 weighs in at 860g as pictured and lost a few more grams before everything was finished. The weight loss resulted in no loss of strength. In fact, every gram you can remove from the pistons and small end of the connecting rod will remove stress from the connecting rod, thus making it more durable.
Careful on selecting aftermarket rod bolts for the endcap style rods. IH uses the bolt threads to align the rod with the cap. Most arp bolts are too short, or have a short threaded portion allowing the cap to "float" on the rod. I need to do some digging to see what arp bolts mimic the stock IH bolts.
 
216114r21 rods do use the same bearings, right? This is a biggie. I thought that IH con rod service report said they did but, now I cant remember. All I can check are the part #s for 345 vs. 392. I did change to heavier rods. Please elaborate on this grey area. The crank is balanced with the rest of the rotating assembly when balancing, right? But theres also polishing which sheds oil quiker, making the crank lighter, right? But I wont see the advantages of polishing unless I also dynamic balane? Am I understanding this right? I finally spoke with the machinist though. Im luckily that he didnt get too far.
 
All IH sv engines with factory internals use the same series of bearings. Meaning that the main, rod, camshaft will have the same o.d. And width (except the main thrust bearing) between a 152, 196, 266, 304, 345, 392. The connecting rod and crankshaft I.d. And main/crankshaft thrust bearing width vary with the service diameter of the crankshaft journals.
So in simple terms, yes, the bearings will work on either style of connecting rods.
It's not so much that the connecting rods (stock form) are different weights. When an engine in mass produced by the thousands there is a spec range for every part made. If everything had to identical, the cost for production would be too much. So there is a range that allows for an increased profit margin and quicker/easier production.
To make things simple, even though the two different styles of connecting rods (stock) didn't weigh the same, they are close enough to say they weigh the same. To give you an idea just how close the two styles are, go grab 5 small metal paperclips, those paperclips weigh more then the difference of my two example connecting rods (stock). It just happened that the two examples I was working with at the time weighed in like they did. The next connecting rods I compare might be just the opposite of the two I posted.
If you're going to balance an IH sv v8 engine. You need to balance it as an assembly. Meaning; flywheel, crankshaft, harmonic balancer hub, connecting rods, pistons, wristpins (locks if required), rings, rod bearings and all the bolts and nuts that hold the assembly together. The person doing the balancing will also add a small amount for oil in/on the rotating assembly.
 
Last edited:
My parts manual for 72 - 73 full size only shows one part number for rod bearings.

Imo -- there is no need to

lighten rods or polish / lighten the crankshaft in an IH (or any) engine that is not going to "see" 5000 rpm

unless you want "bragging rights" over beer with your buddies...

(makes more "sense" in a race engine that "sees" / runs at 7000 - 8000 rpm...)

as stated before, you should have the rods / pistons balanced -- reread robertk's posts #22, #25 and #26 in this thread.

If the crankshaft / flywheel / harmonic balancer come from one engine; then I think you do not need to balance the crankshaft.

But, michael mayben, robertk, or Jeff can speak more authoritatively than I on this subject.

If these three pieces come from more than one engine; then all three should be balanced. The engines were externally balanced on the assembly line when new.

The crankshaft should be dynamically balanced -- I do not know if the harmonic balancer should be attached -- again robertk knows more than I on the subject. Though he did not state exactly what he did on his 152 as far as balancing the crankshaft.

I believe the flywheel should be balanced by itself.

Hth
 
Just have the rotating assy balanced.:gringrin: and ignore all of the other stuff although some is relevant to much of a good thing is still to much of a good thing.

The guy doing the balancing will need one set of rings, one set of rod bearings, all of your new pistons, all of your rods, all of your wrist pins, the crank, the front crank hub or harmonic balancer and the flywheel or flex plate. If you are real critical the pressure plate needs to be doweled and balanced to the and with the flywheel.
All components need to be separate and unassembled.

That is all you need to worry your self with as a good balancing firm will do the rest. I leave nothing to chance when building an engine period and pretty much end of story.

Like robertc stated you are not building a race motor but any motor will vibrate if not balanced correctly. A 35 year old motor cannot be associated to any factory build specs so please "do not" try to convince some one that the factory specs or rod weights are relevant here without even seeing the parts. That is just blowing smoke and irresponsible.
 
Do you still want photos? Dont tell me there were different versions of this rod with the same part #s. Im bringing in my harmonic balancer and flywheel in and maybe I can get a pic.
 
78ih said:
do you still want photos? Dont tell me there were different versions of this rod with the same part #s. Im bringing in my harmonic balancer and flywheel in and maybe I can get a pic.
Click to expand...

If you have r2 rods that is fine. The r2 denoted the better rod. The big difference is where the neck(I-beam) of the rod transitions to the big end. That big fillet allows the rod to take a bunch more tensile loading without distorting the bearing bore and distribute the compressive bearing loading way better. You won't break them with your setup.

I couldn't remember if you had a auto to I through in the pressure plate reference for safety.
 
Yes, I would assume so...

My 72 - 73 IH full size parts manual shows 216114r12 as the 345 rod.

Something you have to keep in mind -- as IH "revised" / "updated" parts they increased the r# -- r1 was the first version; rnn were later versions.

My personal point of view is that you need 8 rods with the same part number -- which is what you seem to have.

From a balance perspective (as 71 Scout 2 pointed out), there is probably only 1/2 gram to maybe 2 grams of weight between the lightest to the heaviest rod.

This does not seem to be much, but you will have a "better" engine if the weights are "equaled out"... With balancing

hth
 
This is where I had /have the problem with the argument that the rods are intended to be interchangeable. How in the heck( self censored) can you say with any certainty that is still true. No one has seen the old rods from 78ih let alone weighed them so how can you say they are still at an IH spec weight.

These statements are absolutely irresponsible and we will not allow them to continue. We can not make statements based on unknown facts. The weights May very well be oem but they May very well not be. Lets error on the safe side.:gringrin:

I bet I can come up with 10 known sv engine builds where the guy has taken a grinder to the small and large end of the rod in an attempt to lighten them. When the crank is bobed and spun the counterweights are then modified to the new lightened rods. How do you think those weights correlate to the IH spec now????? How do you know that the engine in question here is a virgin.
Very few of these sv motors are still virgin and untouched.


The total rod weight is not entirely relevant to a 8v balance. The Bob weight that is attached to the rod journals is a very accurate calculated mass. It is a combination of many things like rotating, reciprocating weights in predetermined factors.

If ya got time to read here is a good write up on balancing a "v" engine. It ain't so simple!! crankshaft balance factors
Very few of these sv motors are still virgin and untouched.
 
Last edited:
As I've been "trained" by dave the gear man (who was there on the line when these motors were being machined and assembled, both oem and when performing "factory rebuild" at the factory branch)...

All moving parts were "classed" after being produced as to weight. This is sop in the production side for any manufacturer. As in "classed" for common weight tolerances. Then the parts were kept together for assembly as a set into each engine.

Any parts that were "out of range" were set aside for "rework" (not scrapped). That meant adjusting the weights in various manners to bring into usable tolerance.

The parts sets were then assembled into a completed engine with all designated rotating components and balanced in a process that took approximately 15 seconds to spin up, then 15 seconds to "correct" with automated machinery (not a "robot"), and another 15 seconds to verify the balance correction. If the motor passed inspection, it moved on through the assembly process, if it did not it was kicked offline for rework at some later point.

When these engines were later remanned at a "factory branch", all engine components were kept together as sets as the engine went through the process. Most machine work was done in-house...but if rods/pistons, etc. Were replaced (and in nearly all cases pistons were replaced as oversize), then the replacement pistons were selected from bulk as "weight sets" and again remained together through the process.

If a particular engine had to be extensively repaired outside of the "normal" reman process, then the branch folks selected the replacement parts, sorted for weight, and supplied the sublet machine shop with Bob weight data so that the rotating assembly could be balanced for the replacement parts. And core engines that were returned to the factory branch for reman always included all rotating parts, flywheels, hubs/balancers, etc.

Some factory branches had full machine shop capability in-house, even for dynamic balance operations, some did not and had to sublet as needed.

There is no doubt in my mind that IH factory branches paid far more attention to engine reman detail than any production rebuilder. When the factory branch programs ended around 1985 or so, then ihc contracted with a few national companies to follow these same practices when they intro'd the "renew" line of reman products through the dealer network.
 
michael mayben said:
as I've been "trained" by dave the gear man (who was there on the line when these motors were being machined and assembled, both oem and when performing "factory rebuild" at the factory branch)...

All moving parts were "classed" after being produced as to weight. This is sop in the production side for any manufacturer. As in "classed" for common weight tolerances. Then the parts were kept together for assembly as a set into each engine.

Any parts that were "out of range" were set aside for "rework" (not scrapped). That meant adjusting the weights in various manners to bring into usable tolerance.

The parts sets were then assembled into a completed engine with all designated rotating components and balanced in a process that took approximately 15 seconds to spin up, then 15 seconds to "correct" with automated machinery (not a "robot"), and another 15 seconds to verify the balance correction. If the motor passed inspection, it moved on through the assembly process, if it did not it was kicked offline for rework at some later point.

When these engines were later remanned at a "factory branch", all engine components were kept together as sets as the engine went through the process. Most machine work was done in-house...but if rods/pistons, etc. Were replaced (and in nearly all cases pistons were replaced as oversize), then the replacement pistons were selected from bulk as "weight sets" and again remained together through the process.

If a particular engine had to be extensively repaired outside of the "normal" reman process, then the branch folks selected the replacement parts, sorted for weight, and supplied the sublet machine shop with Bob weight data so that the rotating assembly could be balanced for the replacement parts. And core engines that were returned to the factory branch for reman always included all rotating parts, flywheels, hubs/balancers, etc.

Some factory branches had full machine shop capability in-house, even for dynamic balance operations, some did not and had to sublet as needed.

There is no doubt in my mind that IH factory branches paid far more attention to engine reman detail than any production rebuilder. When the factory branch programs ended around 1985 or so, then ihc contracted with a few national companies to follow these same practices when they intro'd the "renew" line of reman products through the dealer network.
Click to expand...

Yes, I agree with this when talking about an IH approved rebuild or factory virgin build.

No, I do not agree this has any real validity with the engine being ddiscussed in this thread. There is just no way to know it's history and thus the component weights. I will not speculate or suggest any plan of action other that to have it re-balanced or risk a poorly balanced assembly.

Rk
 
That was my point exactly Robert!

The "factory" and the "factory branches" had methodology and parts in place to do the right thang. Today, that's just not possible! We're just lucky to be able to find a set of eight oversize pistons in stock spread over five warehouses and they all turn out to be the same brand and design (remember the conversation regarding the sil-vo-lites hyperu's for tim??). We don't have one hundred on the shelf to grade/sort into a set of eight mating items by weight and diameter!

Today...we must plan that every engine, whether a runner or a core has been previously butchered in some manner by a po or by a commercial shop that May have had worse work habits than any po. A perfect example, this Ford fe we've been struggling with that was "just rebuilt" but had a crankshaft so plugged with bearing debris that it hadn't lubed in years! And...it had the oem bearings in it from 1963! Same goes for all the peripheral stuff, rocker assemblies, ignition, carburetion, etc. This shit is 35+ years old, there ain't no verified virgins out there (except for maybe lou dinwiddy???)!

Same for these sv motors that have had flywheels, clutches, flex plates, crank hubs, etc. Boneyarded and swapped around for ages! Or had one rod/piston assembly replaced with parts from two different motors and then shakes like a bobblehead when spoolin' up!

If you are gonna build a motor...and build a motor correctly, it gets balanced! And if inspection shows the internal components have been butched, then they must get sum love in some manner before sending out for a balance job.

This same exact discussion is how dave and I met. John tabor and I were having a heated discussion about 345 balance after he had performed a clutch replacement for a customer. John's only replaced prolly 200+ clutches and flywheels in Scout II in his lifetime. But this one ate him...three trys and it had only got worse!

Dave was sittin' in the booth behind us at vida cafe and asked if he could offer his "opinion"! Over the next three hours the sumbitch trained us old farts regarding balancing IH guapo....and now ya know the rest of the story!

So what did john do??? Last I heard, he had the entire replacement clutch/flywheel setup neutral balanced and that solved the problem.
 
Robert kenney said:
A 35 year old motor cannot be associated to any factory build specs so please "do not" try to convince some one that the factory specs or rod weights are relevant here without even seeing the parts. That is just blowing smoke and irresponsible.
Click to expand...

True, if the parts in question where used and not straight from the factory.

78ih said:
I just bought nos 216114r21 rods, they had a little surface rust so, the machinist May hone em after cleaning em. But 360 for 8 isnt bad. Balancing is somthing else I havent considered. I was going to install the pistons myself, but do you have an idea of how much more balancing would run? I dont plan on running it very high alot, mostly shifts. I was used to doing 70 mph top speed before and I probably wont push it too much further than that. But 4800 rpm sustained sounds awsome. I can see how it would need to be balanced.
Click to expand...

But the parts in question are "new", from the factory, never been in an engine. And might of come in a box that might look something like this.

picture.php


That is how I base my "irresponsible, smoke blowing" facts.
 
Here we go again.

I recommended first off to have the ra balanced so. Period. Anything else is pure arguing.

What you don't seem to understand is the fact that the rest of the engine is fully unknown. The crank way very well have been balanced to who the f**k knows. So why state the rods are fine if simply installed because thew are a matched oe set. What were the old rods weights that the crank May have been bobbed to? Maybe you have some special powers that you are not telling us.

Until you actually weigh the parts you don't know anything to base even the slightest point that it May be fine if not balanced.

"have it balanced" or risk an imbalance issue.

That is the only responsible statement to make.


This thread is now locked because nothing further can be said that will further help 78ih with his build.
 
Status
Not open for further replies.
Back
Top