152 Camshaft info

VEH

VEH

Member
Ok, I found a reground cam. They also have a preformece regrind. To regrind a cam you need to take from the bottom to keep the lift right. Preformace is more lift, more off bottom. You cant adjust the rockers on a 152, so what longer push rods? Help please
 
Depends on what the reduction in base circle is to achieve the performance grind. Most times you will be ok but I recommend verifying lifter preload after installing the new cam.

If you find insufficient preload then Jeff can get you longer pushrods.

As for performance and cam specs: lift = peak torque value and duration = horspower.
 
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Thank you, what type of performance can I get from your cam? If I do need push rods what kind of money are we talking?
 
veh said:
thank you, what type of performance can I get from your cam? If I do need push rods what kind of money are we talking?
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You will have to call us here at the shop for definitive information regarding the I-4 camshafts, we have those custom ground for us. But I can assure you, even though they are regrinds, the base circle has not been reduced. If a more radical cam is desired that can't be done by a regrind, then the core is simply welded up and then ground. Sometimes we have cams ready to go on the shelf, sometimes not but can obtain 'em very quickly, this is based upon having an adequate supply of cores.

The phone number here is 530.268.0864, ask for Jeff.

By making a purchase such as this from a knowledgeable source and not some on-line/egay vendor, you do have recourse and receive all the technical support you will ever need in the event of some sort of anomaly. We were the first of the IH specialty vendors to get into the I-4 performance cam supply bizz and have this nailed down pretty good....we have had issues with exactly one cam for a 152 regarding an "appearance" issue after a weld job that had no impact whatsoever on actual performance or operation. Since then we have had no issues whatsoever.

Can you expect a big performance gain by simply installing an aftermarket spec cam???? Hell no! These are tractor motors and it takes alotta work to turn one into a performance engine...but it can be done and several of us around here are doing it right now!

On the other hand, we find nearly all I-4 camshaft cores to have at least one flat lobe, that is reason why engine performance seems to improve after the replacement cam is installed,...all of a sudden the motor has equalized cam timing and combustion pressure for the first time this century! All I-4 cams are regrinds, the camshaft industry simply does not have access to new cam blanks for this purpose, but we do have new blanks used on our sv cams.
 
Say, michael...

After our conversation at the ihon mother-ship last Friday, you got me to thinkin'. :idea:

now that I'm now open to the possiblity that the camshaft in my 196 May have a flat lobe, is the only way I can tell if it's flat is to remove it and Mike it? Or can I adequately assess it while still installed?

Exactly what do I look for? Measurements? :confused5:
 
Mark pietz said:
say, michael...

After our conversation at the ihon mother-ship last Friday, you got me to thinkin'. :idea:

now that I'm now open to the possiblity that the camshaft in my 196 May have a flat lobe, is the only way I can tell if it's flat is to remove it and Mike it? Or can I adequately assess it while still installed?

Exactly what do I look for? Measurements? :confused5:
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You can make a rudimentary setup with a long-travel dial indicator zero'd on each rocker arm directly over the pushrod pocket and measure the lift from base circle (zero the indicator at that point) to max height on the lobe while carefully rotating the crank hub with a wrench. Each lifter should hold pressure in an adequate manner to act as a "solid" lifter for doing this.

Ideally, all lobes will be equal in "height" within a few thousandths. For all the "flat" cams I've checked for the four banger motors, about 0.020">0.030" seems to be the norm for wear on only one or two lobes. Some of 'em have had virtually no lobe however, but those engines appear inside to have been severely overheated and most likely run with a very blow oil volume also, cam bearing babbit layer com[completely missing, etc.
 
Mark pietz said:
I have a 0-1" travel dial indicator. Will that be enough travel to Mike these things?
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Sure, the actual lift on the cam lobe is less than a nominal 0.250", somewhere around 0.217">0.222" from what I can remember right now. A dial "test" indicator probably would not have enough travel.
 
Thanks.
I found r. Kenney's picture of his setup for doing this; I'll probably be heading down that same road.

Are there visual signs to a lobe going flat, I.e., discoloration, etc.
 
Mark pietz said:
thanks.
I found r. Kenney's picture of his setup for doing this; I'll probably be heading down that same road.

Are there visual signs to a lobe going flat, I.e., discoloration, etc.
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None of the cams I've seen with flat /worn lobes looked any different except it was obvious that when eyeball comparin' the lobe height with an adjacent lobe that was not damaged you can definitely see the difference. Also, the surface finish is going to be somewhat more rough and erratic instead of having a polished appearance. If the lifter that mated with the lobe is cupped, then that is an obvious clue.
 
Stock lobe lift on the 4 popper is .224.

That is also what I measured on my old one before having a performance grind put on it.
 
Mark pietz said:
are there visual signs to a lobe going flat, I.e., discoloration, etc.
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The nose must be perfectly flat from edge to edge and the mating lifter must be absolutly free of any cupping/concave dishing. Also the surface should be shiny and smooth.

If the cam exibits any of the above it is toast from a useable cam standpoint. Your popping issue however will (if caused by a flat cam lobe) have to be down better than 50% of the spec lift and on an exhaust lobe not an intake.
 
Robert,
tx again. We'll find out soon enough! A few days ago I dropped the tank and it had a solid layer of about 3/4" worth of rust sediment and nasty varnish. Sending unit was mostly dissolved. It's being boiled out now and coated, and I'm replacing that 20' worth of vapor hose venting hose back there around the tank because it was hard, broken off, or missing! Plus Jeff had a new sending unit on the shelf and he's only 45 minutes away. So I'll have a nice, clean, refurbed fuel system, which is essential to anything else I do with the rig.

In a couple of weeks it will be up on blocks, the front clip comes off, and the fun begins.
 
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