Considerations for Installing Isky Cam

G

Grasor

Member
Hey guys,

I have an isky cam here, pn: 190125-26 and wanted to know what special considerations I needed to follow.

1) from reading through the forum I hear the isky lifters aren't so good, should I send them back to isky and get another brand?

2) do I need to replace any of ther other valve components with anything special?

3) I'm going to have a machinist install the cam, but I like to stay on top of them in knowledge as best I can, anything about the timing to consider when installing this?

Thanks
g
 
What is the displacment of the engine the cam going into?
Where are you going to want the bulk of the torque?
What freeway cruise rpm are you going to see(65 mph)?
Compression ratio?
Headers?
Carburator type?
You will need to know the answer to these questions before getting more specific on cam timing.

I would not expect you to have any issues with the lifters supplied in the cam kit from isky provided all other things are correct.
 
What is the displacment of the engine the cam going into?

345 v8

where are you going to want the bulk of the torque?

Low/mid if possible.

What freeway cruise rpm are you going to see(65 mph)?

Pretty sure the rpm is somewhere in the 2200 rpm range. 727 trans, 3.73 gears, 31" tires.

Compression ratio?

9 to 9.5

headers?

Yep

carburator type?

Edelbrock 1406 (600 cfm)
 
Thanks, the dee-tails help.

Your projected cruise rpm is low you'll be at 2650-2750 depending on converter slippage. That is good because your other add-ons will reinforce those kinds of rpms and have plenty of torque on demand.

The following assumes an 345e with flat top pistons, silvolite are best.
It is absolutely imperative that the engine have a quench distance of .040-.045. Fyi quench distance is the distance from the top of the piston to the flat portion of the head that overhangs the bore. That equates to the piston being dead flush with the deck when at tdc and running a typical felpro blue permatorque head gasket. They have a compressed thickness of .040-.043. That gives you the perfect quench, detonation resistance and burn efficiency.

For starters I would stay at 110 intake centerline. Go to 108-106 (2 or 4 degrees advanced) if you don't mind the possibility of having to burning 89 octane (mid grade).

If you back off and stick to 9-1 cr you are good for 108-106 intake lobe center line. I assume the machine shop will really degree your cam?
 
grasor said:
hey guys,

I have an isky cam here, pn: 190125-26 and wanted to know what special considerations I needed to follow.

1) from reading through the forum I hear the isky lifters aren't so good, should I send them back to isky and get another brand?

2) do I need to replace any of ther other valve components with anything special?

3) I'm going to have a machinist install the cam, but I like to stay on top of them in knowledge as best I can, anything about the timing to consider when installing this?

Thanks
g
Click to expand...

Let's not interpret the information that has been posted regarding issues with a very few iskenderian-supply lifters to be a blanket condemnation of the isky product. In fact, when isky was contacted about this issue they jumped through hoops to correct the issue immediately. And due to the total lack of movement in inventory on specialty items such as isky lifters for an IH application, they could have been on the shelf for 15 years!

Personally, if I had a set of isky lifters here in the shop right now, I'd use 'em no questions asked and I would not take 'em apart for inspection before ploppin' in the hole. If any new lifter simply does not seem to perform in an adequate manner, then it gets removed and inspected.

Since ihon has become very active in promoting iskenderian products over the last several years, we know that isky's inventory turnover has greatly increased.
 
Rob you sound like you know a thing or two. That said I hope to jeebus you're wrong about the rpm at 65 mph haha. I was prob thinking of 55-60 mph. The tech at isky swore up and down the diff. On fuel economy would be negligible. Of course, I don't drive it daily anymore so maybe I could make the trade off. If I hit 89 octane, meh, I only drive it a couple thousand miles a year, that's not much difference on fuel costs.

I'll forward you're post on to the machinist and see what he thinks. He's highly recommended by the local hot rod shop so I imagine he knows what he's doing, but never hurts to have more info on hand than less. I don't know what brand of pistons are in there, but they are def. Flat top.
 
michael mayben said:
let's not interpret the information that has been posted regarding issues with a very few iskenderian-supply lifters to be a blanket condemnation of the isky product. In fact, when isky was contacted about this issue they jumped through hoops to correct the issue immediately. And due to the total lack of movement in inventory on specialty items such as isky lifters for an IH application, they could have been on the shelf for 15 years!

Personally, if I had a set of isky lifters here in the shop right now, I'd use 'em no questions asked and I would not take 'em apart for inspection before ploppin' in the hole. If any new lifter simply does not seem to perform in an adequate manner, then it gets removed and inspected.

Since ihon has become very active in promoting iskenderian products over the last several years, we know that isky's inventory turnover has greatly increased.
Click to expand...

Thanks for the info Mike, I know ihon only carries the "good stuff" and my machinist recommended I go isky as well because he knows they are a great brand.
 
grasor said:
rob you sound like you know a thing or two. That said I hope to jeebus you're wrong about the rpm at 65 mph haha. I was prob thinking of 55-60 mph. The tech at isky swore up and down the diff. On fuel economy would be negligible. Of course, I don't drive it daily anymore so maybe I could make the trade off. If I hit 89 octane, meh, I only drive it a couple thousand miles a year, that's not much difference on fuel costs.

I'll forward you're post on to the machinist and see what he thinks. He's highly recommended by the local hot rod shop so I imagine he knows what he's doing, but never hurts to have more info on hand than less. I don't know what brand of pistons are in there, but they are def. Flat top.
Click to expand...

My rpm statement is not my opinion but calculated based on tire diameter and r&p ratio. You can check your self by finding an online calculator. Randys ring and pinion has one. In fact go here and have a look. I get 2698 @ 65.

randy's ring & pinion. Rpm calculator.
 
Robert-
so what if he does Want to advance the cam 2-4 degrees? Not easily achieved w/ ihc valve gear. I followed yours and mayben's thread about offset keyways, but never heard the final result. I installed my cam straight up mostly because I didn't have an easy way to manipulate it (like on a GM for instance).
What are your thoughts on this?
 
I make the offset keys to put the timing where ever the customer needs it. I have not made any for engines other than ones I build.

First install the cam and determine the existing location and then decide the relative shift required. Works like a charm.
 
Can you post a pic of one, or is it something proprietary? I am having trouble getting my head around the "offset" theory. I am picturing two squares sitting on top of each other (the end view of the key), except one of the squares is farther left (or right) depending on the direction and duration of change. Does that make sense? And it would seem from a physics standpoint that if you offset the key much more than half the width of the material you would have a flimsy locating key.
Have I lost you? I'll try to post a drawing of what I am describing.
 
dealbreaker74 said:
can you post a pic of one, or is it something proprietary? I am having trouble getting my head around the "offset" theory. I am picturing two squares sitting on top of each other (the end view of the key), except one of the squares is farther left (or right) depending on the direction and duration of change. Does that make sense? And it would seem from a physics standpoint that if you offset the key much more than half the width of the material you would have a flimsy locating key.
Have I lost you? I'll try to post a drawing of what I am describing.
Click to expand...

You got it!

For illustrative purposes, look at this page:

crankshaft keys: star performance

The offset keys for chryfordrolet are a dime a dozen anywhere. Not so for ihc stuff as there was no market for that item whatsoever.

But...due to the ability of Robert to set up and actually produce/verify camshaft/drive gear data here on the ihon forum, we now know that any cam (including a nos cam) "could" be out of spec. Ya won't find this kind of information regarding ihc junkiron anywhere else on the 'net unless it's been plagiarized! Robert has done a tremendous amount of behind the scenes work on this subject that is not and never will be posted around here as it is proprietary in nature. But he does make recommendations knowing these variables and can recommend a "fix" when needed! That is why we have to be very careful around here regarding accuracy of information, we don't want to risk burning our sources which would turn off the tap!

And my good buddy who worked in the ihc factory branches has told me many times that the crankshaft keyway position can be up to 4* advanced or retarded also right off the machining line. He also related that at one point, the factory branches where the fleet rebuilds were done regionally had a selection of offset cam keys available to use when doing engine builds in mass. These were parts produced by ihc only for use in the factory branches, they were not available as a routine service part, this was not an unusual deal and explain why we sometimes find stuff with these motors with an unknown history that are "different" but obviously done correctly.

At one point back in the day, isky actually offered ihc cam drive gears that had been modded with multiple keyway offsets for use in "selective fit" apps. Robert has a very inside door into isky and has confirmed this.
 
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Robert kenney said:
my rpm statement is not my opinion but calculated based on tire diameter and r&p ratio. You can check your self by finding an online calculator. Randys ring and pinion has one. In fact go here and have a look. I get 2698 @ 65.

randy's ring & pinion. Rpm calculator.
Click to expand...

I figured as much. You know, I have spent more time "upgrading" the Scout in the past couple years than actually driving it, so this has likely been the case I just didn't remember correctly.

Sounds like you know how to dial in the cam fairly well. I don't know anything about the process and figured it all only goes together one way, which doesn't sound quite like the truth based on what I'm reading. I guess I'll talk to the machinist about the cam when he gets it, and if he needs any offset keys, and can't source them himself, I'll have to ask you if you can supply any.

Thanks!
 
dealbreaker74 said:
can you post a pic of one, or is it something proprietary? I am having trouble getting my head around the "offset" theory. I am picturing two squares sitting on top of each other (the end view of the key), except one of the squares is farther left (or right) depending on the direction and duration of change. Does that make sense? And it would seem from a physics standpoint that if you offset the key much more than half the width of the material you would have a flimsy locating key.
Have I lost you? I'll try to post a drawing of what I am describing.
Click to expand...

The keys are nothing more that a typical offset key you would get for a sbc so not a secret but.... The IH is different than any of the big 3 use size wise.

I made a special indexable fixture to machine anything I want interms of degrees.

First you offset the cam key and not the crank key. Eg if you want 4* advance you advance the cam 2*. The offset is really small so you will not likely ever run out of meat. If you need more than that you can shift a tooth and end up where you want. Each cam gear tooth is 8* at the crank.
I have some good pictures of an offset cam gear that I can post later.
 
Robert kenney said:
my rpm statement is not my opinion but calculated based on tire diameter and r&p ratio. You can check your self by finding an online calculator. Randys ring and pinion has one. In fact go here and have a look. I get 2698 @ 65.

randy's ring & pinion. Rpm calculator.
Click to expand...

Just for a real world comparison, with my Scout's setup (727 trans, 3.73 axles, 33" BFG a/t tires), I'm getting around 2600-2700 rpm at 65 mph. This is with my 4000 rpm auto meter tach.
 
dealbreaker74 said:
can you post a pic of one, or is it something proprietary? I am having trouble getting my head around the "offset" theory. I am picturing two squares sitting on top of each other (the end view of the key), except one of the squares is farther left (or right) depending on the direction and duration of change. Does that make sense? And it would seem from a physics standpoint that if you offset the key much more than half the width of the material you would have a flimsy locating key.
Have I lost you? I'll try to post a drawing of what I am describing.
Click to expand...

Sorry I forgot I said I was going to post a picture. Here is one. I have to use two keys due to the woodruff radius and thicknesses that are available. They are then machined to the required offset as a pair. The step is not simply stepped over perpendicular it is radially indexed so the faces actually have the correct angle on them and fit tight.
 
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Thanks Robert. That's pretty much how I envisioned it. I wasn't thinking of using two keys, but the reason makes sense. How many degrees is that setup? Looks minute, but a small change at the shaft probably makes a huge difference at the gear. Good info.
 
I would have to go back through my notes but iirc it is 2 1/2* at the cam and 5* at the crank. Typical for an sv to need 4-5*.
 
Robert, I just received my parts from IH only and will be bringing pistons etc... To the machine shop Monday. So I will soon be assembling the engine and checking cam timing. If it is not desirable do you offer these offset keys for purchase?
 
Hi Mark,
sure if you need one I do make them for the IH brothers.
Just have to let me know where the cam installed and where you want it. Eg it went in with the intake lobe at 112 and you want it at 106* I'll send you a key that will advance your cam 6* at the crank (3* at the cam).

Just shoot me a pm
 
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