[68 Firebird]

Subscribed

[ponjohn]

Originally Posted by LMSRACER

You may find that the Base Circle on the Camshaft was Ground Improperly. Too Small to be clear.
That would cause the Lifter to drop down out of the Lifter Bore Excessively while Riding on the Cams Base Circle.

With a Custom Cam Grind, this can be Dictated, to a Degree, by the Purchaser.

Larry S.

Larry-

If I am ordering a cam for a traditional Pontiac, shouldn't the base circle be the same?

[b-man]

Originally Posted by ponjohn

Larry-

If I am ordering a cam for a traditional Pontiac, shouldn't the base circle be the same?

You're limited by the size of the cam bearing bores in the block, so in order to get a lot of lobe lift you need to reduce the base circle.

This is why the big boys use 55mm or 60mm cam bearing bores in their aftermarket blocks, instead of stock-size cam bearing bores.

[LMSRACER]

Originally Posted by ponjohn

Larry-

If I am ordering a cam for a traditional Pontiac, shouldn't the base circle be the same?

The Base Circle can be Altered. Just like a Small Block Chevy needs a Reduced Base Circle Diameter to Clear the Connecting Rods in a Stroker Application.

Like B-Man Stated, as the Lobe Lift is Increased, the Base Circle Diameter is Often Reduced. By Reducing the Base Circle Diameter You've Actually Increased the Lobe Lift.

Keep in Mind that the Height of the Lobe CANNOT Exceed the Diameter of the Cam Journal. If it did you wouldn't be able to install the Cam in the Block. The Lobes couldn't get past the Cam Bearings.

In My Experience with the Pontiac Lifter "Oil Band" Issues, I have had Camshaft and Lifter Combinations that Actually Allowed the Lifter to Ride so far down in the Lifter Bore that the Oil Band was Sticking Out below the Base of the Lifter Bore. The Cam and Lifters were from the Same Manufacturer.

I think that answers your question.

Larry S.

[tom s]

Crowers are Johnson and they are SBC with diff link bars.Just look at the part numbers,same but with diff letters after the body number.The new Comp bodies are diff from the old and virtually all the other Hyd roller lifters I have looked at.I would almost bet they are SBC bodies thou.I just know I have 3 engines running them at this very moment and no noise.From 380 to 400 lobe lift Comp high lift Hyd roller cams.They are in my 366 RA V engine,my 455 RAIII clone engine and a KRE headed 455 engine and am putting a new set in my 421 SD engine now.FWIW,Tom

[HWYSTR455]

Subscribing.

I have a set of Howard's, which are Morel, haven't installed yet, and would prefer to get it right the first time.

EDIT: I have a set of Howard's in the Olds engine, they were noisy at first, then quieted down, figure there was packing goo hardened in the bodies. (that flushed over time). Same part number as the Pontiac lifters.

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[TedRamAirII]

Originally Posted by HWYSTR455

Subscribing.

I have a set of Howard's, which are Morel, haven't installed yet, and would prefer to get it right the first time.

EDIT: I have a set of Howard's in the Olds engine, they were noisy at first, then quieted down, figure there was packing goo hardened in the bodies. (that flushed over time). Same part number as the Pontiac lifters.

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I saw a post from Paul Carter about MOREL not being correct, the oil band was not located correctly (chevy lifter?) Dont know why someone cant cant make a correct lifter?

[HWYSTR455]

Originally Posted by TedRamAirII

I saw a post from Paul Carter about MOREL not being correct, the oil band was not located correctly (chevy lifter?) Dont know why someone cant cant make a correct lifter?

Yeah, and in this thread as well, which is why I'm paying attention. I'm about at the point of installing mine, so need to figure it out before I do.

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[TedRamAirII]

Originally Posted by HWYSTR455

Yeah, and in this thread as well, which is why I'm paying attention. I'm about at the point of installing mine, so need to figure it out before I do.

.

Whats funny is the pic for a regular lifter looks different from Pontiac to Chevy, but not the roller?

[HWYSTR455]

Originally Posted by TedRamAirII

Whats funny is the pic for a regular lifter looks different from Pontiac to Chevy, but not the roller?

Photobucket is blocked for me, I only see some of the pics. I would have to wait until I get home to see the Photobucket ones.

I prefer when pics are actually posted to the site, since then it's here to stay. I've gone back on thread searching stuff and found where the link was defunct, because the pic had been removed from the external location.

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[LMSRACER]

Originally Posted by gtofreek

There has been a lot of complaints about noisy hydraulic roller lifters. We've been round and round with this ourselves with a 326 we put a roller cam in. They were Morel lifters, sold by Lunati. We called the owner of Morel after the first set was noisy, and he agreed to make us another set. We installed them, and just like the previous lifters, they were quiet for the first minute or two, then they started getting noisy again. After 2 minutes, they were noisy as can be. I have been saying right from the start that the problem is with the placement of the oil band. It is too low, and at the base circle, it drops out of the oil hole, so no oil pressure is present while on the base circle, so no oil to refill the lifters at the critical time when they need the oil. After all, the lifter can't refill while under pressure from the springs.

So the apparent fix is to elongate the oil hole in the block to extend it down another 1/4" so it is open to the lifters oil band while on the base circle. Obviously this is not an option for the assembled engines with this problem. So what we did was cut a groove in the lifter body to extend it up about .150" so it can see the oil hole while on the base circle. Here is a pic of the modification. I will post when I get the affirmation that it fixed the problem for sure.

We have had two lifter manufacturers tell us that they use Chevy lifter bodies for the Pontiac lifters because they don't want to tool up to make a specific lifter for a "limited market", according to them. Well, maybe, just maybe, if they made the parts right in the first place, more people would buy them. But with the current complaints of noisy lifters, people are gun shy of using them. They tell us 90% of all noisy lifter complaints they get are from Pontiac owners. WELL, MAYBE THAT'S BECAUSE THEY DON'T MAKE THEM RIGHT! Did they ever think of that?

Paul's Right..
I'm assembling a Pontiac 400 right now and it has the Morel Lifters and an "Off the Shelf" Hydraulic Roller Cam. The Oil Band is Too Low for Sure.
I'll be modifying these lifters.

Let me say something about the Oil Band... It's Only an Issue with Hydraulic Flat Tappet Lifters and Hydraulic Roller Lifters due to the Operation of the Lifter Itself....
On a Solid Roller and Solid Flat Tappet Cam you'll find that the Oil Hole in the Lifter Body, in most cases, is PURPOSELY NOT Supplied Oil 100% of the time. This is done for "Oil Metering" Purposes. In Fact, Often Times the Lifter has what is known as "Edge Orifice" Oiling. That means that the Oil Hole isn't Located Inside the Oil Band at all. Instead it's Located Along the Smooth Portion of the Body of the Lifter.
BUT, Even with a Solid Flat Tappet Lifter or a Solid Roller Lifter, Make 100% Sure that the Top or Bottom of the Oil Band DOES NOT Protrude, or Stick Out, Past the Lifter Bore while Riding on the Base Circle of the Cam or at Max Lobe Lift. If it is and you don't catch it, the Lifter Bores will Wear Out Quickly because the Lifter Body will not be Properly Supported.

Larry S.

[73ta]

Suscribed. I am running older CC Hyd Rollers.

[gtofreek]

Originally Posted by HWYSTR455

Subscribing.

I have a set of Howard's, which are Morel, haven't installed yet, and would prefer to get it right the first time.

EDIT: I have a set of Howard's in the Olds engine, they were noisy at first, then quieted down, figure there was packing goo hardened in the bodies. (that flushed over time). Same part number as the Pontiac lifters.

.

What's important to note of is if the oil hole in the block will line up with the oil band in the lifter, when the lifter is on the base circle. I can't remember how Olds is, but Pontiac just has a 1/4" hole, closer to the top, than the bottom. Because of this, the band drops below the hole at base circle. This is the critical time the lifter needs to refill itself. If the Olds oil hole lines up with the oil band at base circle, you're golden!

[vidguy]

Good job getting deep into this..

Hopefully my build will benefit from what you learn here..

[JLMounce]

subscribing as I'm looking at roller cams at this point.

[71 T/A]

So since the later Comp Camps HR lifters, part# 857S seem to have few complaints, is this now the preferred HR lifter?

[i82much]

i have the new comps on the OF cam. it did not take long for my top end to see oil the first time i primed the engine, and my lifters are not noisy. perhaps the ia2 galleys are in a different place?

on the other hand, it seems like you might be able to get enough oil in the lifter even if the band does not see the oil galley on the base circle. you still get oil in the way up and in the way down, the question is can you meter it so that is enough to keep the lifter from collapsing?


what kind of spring pressure are you running?

[JLMounce]

Originally Posted by i82much

i have the new comps on the OF cam. it did not take long for my top end to see oil the first time i primed the engine, and my lifters are not noisy. perhaps the ia2 galleys are in a different place?

on the other hand, it seems like you might be able to get enough oil in the lifter even if the band does not see the oil galley on the base circle. you still get oil in the way up and in the way down, the question is can you meter it so that is enough to keep the lifter from collapsing?


what kind of spring pressure are you running?

I guess the question is how much lobe lift on the cam until you start seeing this become an issue?

[HWYSTR455]

Here's a pic of the Howard's boxed Morels...

The rule is even with the body, the pic makes it look like it isn't. (crappy phone pic)

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[i82much]

Originally Posted by JLMounce

I guess the question is how much lobe lift on the cam until you start seeing this become an issue?

You mean if the base circle gets smaller?