Loadstar 1600 with 345

No doubt in the later years many service parts were "substituted". Sometimes with documentation to the dealer base, sometimes not.

And because nearly all of the light duty engines in all configs ended up in some kind of companion ag/industrial/marine configuration which were completely separate applications, there is much we can't find out about the hierarchy without alotta digging!

One of my contacts who was "there" tells me that while there was basically a single foundry point for engine components sourced in-house by IH, the various bits and pieces were sent out to two different assembly points for final machine and buildup. One for "motor vehicle/truck", and one for the ag/industrial side of the bizz. And now, 40+ years on, we see this stuff blended in ways that could never be done on purpose! Then to add more confusion, we have all the aftermarket parts sources that were active back in the day, but have not continued parts supply in recent history.

In times when there was a "backorder" sitch regarding service parts at the dealer level, a knowledgeable dealer went to the "ag" side of the service parts distribution system and obtained what was needed through that channel though the various "divisions"/factions within IH tried to discourage that workaround.

One more reason why a calendar year compilation of IH-issued service and parts "letters" (bulletins) would be an additional profit center for those folks that deal in repop IH literature.
 
Thanks first of all for the discussion, I'm learning a lot! The number on the timing gear is: 3336b
the journal measurements are as follows:
#1: 2.098
#2: 2.086
#3: 2.078
#4: 2.069
#5: 2.058
just Under spec, according to my manual for a Scout.

Now what appears to be the real bad news, I measured all the lobes starting from the gear to the back. They seem to be all over the place. This was measured with a digital slide caliper measuring the diameter of lobe (tallest point to lowest), I will verifiy with a micrometer tommorow.

Starting with first lobe: 1.745, 1.725, 1.717, 1.707, 1.719, 1.686, 1.715, 1.714, 1.721, 1.717, 1.716, 1.740, 1.714, 1.690, 1.693, 1.721.

Thanks
ron
 
Ron,
the journal diameter is less of a concern. Especially if a caliper is used. A caliper is a guess stick at best not to offend anyone but +/- .003 on a good one is all I would say. The journals look to have the .010 diameter difference they should.

Always use a .0001 graduation micrometer for critical engine measurements.

The lobe is another thing .055 difference between the largest to the smallest.. Time for a new one.:(

you can measure lobe lift by the minor diameter and the major dimension(your posted measurements), subtract the minor from the major for the net lift of the cam. This only works for short duration cams like the IH uses. Possible the cam is a regrind but I would not expect the variation.

Rk
 
Ribert, I hear ya about the slide caliper. My micrometer is at work I wll bring it home tomorrow and recheck. As far off as the caliper shows I trend to agree the cam is shot.
Ron
 
Michael, thanks for posting the document on the engines -- interesting to "read".

Off topic... (again:gringrin: )

hp numbers are interesting, also....

392 w/dual exhaust shows 189 hp net --

the "data plate" on the door of my 73 t/a "shows" 235.9 hp (.9 hp?) net -- 392 CA smog, p/s, p/b, dual exhaust, no a/c...
 
Your timing gear is an aftermarket piece. 3336s is the aftermarket industry standard part # for the set, used by cloyes & melling as is, with a 221- prefix it becomes a sealed power # ect.

How about posting pics of the cam and lifters, particularly the lobes that aren't quite measuring up.
 
I will do that eric, might be tomorrow night though. Just glad tomorrow is Friday. I have the 75 in my shop for a little rust repair before winter gets here. With the 75 and the 74 now this 345 on the engine stand I am not lacking for things to do.
Ron
 
robertc said:
michael, thanks for posting the document on the engines -- interesting to "read".

Off topic... (again:gringrin: )

hp numbers are interesting, also....

392 w/dual exhaust shows 189 hp net --

the "data plate" on the door of my 73 t/a "shows" 235.9 hp (.9 hp?) net -- 392 CA smog, p/s, p/b, dual exhaust, no a/c...
Click to expand...

Robertc...I no longer have access to sae "j" standards.

But...iirc, the j-245 engine ratings system referred to in that doc were part of a general "overhaul" of how production engines were rated based upon more "real world" testing against a standard set of operating conditions...with all accessories intact and at more realistic environmental conditions in the dyno cells.

This was part and parcel of the major upgrade in emissions standards and of course was all spelled out by the feds but "adopted" by the sae as standard practice so it could appear that the manufacturers and the sae were "in charge" instead of the bureaucrats.

There was a "grace period" for releasing this type information and incorporating in vehicle data/documentation...just as the 17 digit vin was phased in and did not magically appear overnight for all oem manufacturers. But all oems had to move to the federal 17 digit vin by m/y '75 iirc (May have been '76??).

Is that confusing??? Then check out that spec for "ama taxable horsepower"!!
 
Ok I'a back with pictures and new numbers. I re-measured all lobes of the cam with a mic. Measurement as follows:

height --- width --- lift
1.746--- 1.492--- .254
1.725--- 1.497--- .228
1.725--- 1.494--- .226
1.7235-- 1.470--- .2535
1.723--- 1.471--- .252
1.687--- 1.461--- .226
1.716--- 1.491--- .225
1.741--- 1.489--- .252
1.7255-- 1.474--- .2515
1.714--- 1.498--- .216
1.711--- 1.484--- .227
1.7405-- 1.485--- .2555
1.714--- 1.463--- .251
1.688--- 1.464--- .224
1.691--- 1.467--- .224
1.724--- 1.471--- .253

now the difference or the height of the lobe is .058 thats alot.
From my manual for a Scout valve lift should be .44 for intake and .395 for exhaust, no where close.
Needless to say cam has some wierd wear in my opinion. Here are some pics of the 2 smallest lobes:
lobe #6
lobe6pic1.jpg

Lobe #6 again
lobe6pic2.jpg

Lobe #6 again
lobe6pic3.jpg

Lobe #14
lobe14.jpg

Cam gear
dscf1373.jpg

Looking closely at the lobes it looks like they are shiny on one side not all the way across.
 
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Ron,
the lobe lift is multiplied by the rocker arm ratio 1.6-1.75. The sv has a rr of 1.75 based on your numbers. I calculated the rr when I went through my 1/2 sv and sorry to say don't remember exactly but 1.69 for one and a different rr for the other rings a bell. Some books publish 1.6 but I don't thing that is right that works out for the two lobe lift values. The lifters look decent from what I can see.

Still even with the variation in lift I would replace it.. Now is teh time when it is easy.

Robert
 
Well I take some of what a I wrote back. Looks like the base circle varies. That would not be attributed to wear but to being reground. The lobe lift values you gave us are basicly 2 values .224 and .254. Good from a wear indication standpoint. The taper is evident on the heal of the lobes and the lifters were rotating. I hope you maintained the order in which you removed them as they must be retuned to the exact same lobe they were running on or you risk eating the cam. If not new lifters should be installed.

My opinion is to replace the cam in either case. Just not enough money to go through the teardown again.

Robert
 
Appreciate your input Robert, a couple of questions, this info is deeper than I am familiar with such as rocker arm ratio? The lift values of .224 and .254, are you saying that is right? Or am I missing the connection or calculation for valve lift? The manual shows more .44 and .395. Or is it the fact this is from a 1600 loadstar instead of a Scout?
To answer your question, yes I have kept all lifters organized with cam, lifters and push rods. But this rebuild is a long term project so I will take my time and replace parts that need to be replaced, if, and it looks like it is, the cam needs to be replaced. I agree nows the time to do it. It will be interesting to see what the machinist has to say about the block.
As I write its getting clearer, your taking the .254 x rr say 1.75 to get valve lift is that correct? Nevermind you had 2 posts I missed the first one until now, yes I am slow!
Thankagain
ron
 
Ron,

you are correct. Valve lift = rr x lobe lift. 1.75 x .224 =.392 @ the valve. 1.75 x .254 = .444. This is only close because the rr is really unknown. It looks close but you still show a lot of variation in your lobe dimensions.

Rk
 
IH sv's have different rocker ratio's for the intake and exhaust. Depending on style they are either 1.5 intake (early welded), 1.7 exhaust, or 1.6 (later boat style) and 1.7 exhaust. The lobes with .25x" are intake lobes. The lobes with .22x" are exhaust lobes. Sv v8 cam lobes go I, e, e, I, I, e, e, I, I, e, e, I, I , e, e, I, from one end to the other.
As others have said the shop manual is referring to valve lift, not cam lobe lift (or lifter lift).
 
Thanks for the info "71", since I have boat style rockers and your info. Rr for this would be 1.6 intake and 1.7 exhaust.
Just averaged the measurements and I have .404 intake valve lift, spec says .44 and .3809 exhaust valve lift spec says .395. The manual does not give an acceptable range for valve lift but I am sure less valve lift means less hp. This just verifys what we've said; time for a new cam.
Ron
 
Ron,
in a very general sense. Lift = torque and duration = hp.
Now while duration makes hp it also effects where the hp and torque will occur. So for a truck/Scout you want the most lift in the shortest time(duration) to give you big torque numbers.

If you compare the cams Jeff sells you can see that the isky cams have better lift velocities than the comp grinds. More lift in a shorter duration.

Next we need to flow a set of sv heads on a flow bench I have access to and see what really effects the flow numbers. The flow of the port valve in is important to how we cam it. No reason to over cam a set of heads. That can kill torque curves.

Rk
 
Looks to me like you have a sloppy re-grind. The stock IH sv cam is a one size fits all, 266-392, Scout to loadstar.

It is a dual pattern cam, and they also use different rocker ratios for intake and exhaust due to the canted valve arrangement. 1.6 intake and 1.7 exhaust iirc so if you apply that to your cam you give you a net avg lift of ~.410 int and ~.383 exh.

The fact that the pattern on the base circle is so wide and the fact that those lifters pictured have about doubled from their initial pattern means the cam and lifters are toast.
 
Robert, I don't know all the differences in cams but I am learning. That's why I am here, the best knowledge base for IH on the web! I know ihon has a favorite they sell:
isky-190125-26 when I buy one it will be from here.
I appreciate all the advice I am getting here it's great!
Ron

eric, the more I tear into this motor the more I find what appears to be a bad rebuild. It does not appear to have very many miles on this rebuild. Cam bearings and rod bearing show uneven wear. Parts of these bearings show no wear where other parts are nice and shiny. I will try to post some pics later.
 
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ronmc1954 said:
Eric, the more I tear into this motor the more I find what appears to be a bad rebuild. It does not appear to have very many miles on this rebuild. Cam bearings and rod bearing show uneven wear. Parts of these bearings show no wear where other parts are nice and shiny. I will try to post some pics later.
Click to expand...

You need to keep in mind when examining the bearings that there is a "load side" that will wear more. The bottom of the cam bearings and the top half of the rod bearings will wear more. What you are looking for is for the shinny areas to be pretty much the full width of the bearing. The concern would be if they were off to one side or where they aren't supposed to be, which could indicate a bent or improperly machined component.
 
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