FH Valve Springs

[frnkeore]

I have another question for the guy's that run, hotter cams.

What is the minimum, installed pressure and the maximum open pressure, for a .375, lift cam, that will turn 5500 rpm?

Pictured is Isky's valve spring spec's, are they good for 5500 rpm?

Also, I have read on this forum, that you have to watch out for higher pressure springs, because they will wear the cam out.

What is the reason that the cam will wear so fast, with what I think are fairly low pressures. In modern, OHV valve engines, we run 300+ lb, open pressures, w/o any cam failure issues.

Thank you,

Frank

[Bored&Stroked]

The Isky 185-G spring is just fine for what you're doing - install it at 2.00". What you didn't mention was size/weight of valves, what type of lifters, etc.. With just a .375 lift cam and 5500 redline, you'll have no problem with just about any valve gear you're using - 85 lbs on the seat is actually more than you'll need. You can easily get away with LZ springs - which at 2" are closer to 80 lbs. (I just checked some for Mac VanPelt today).

If you want a set of LZ springs, call Mac VanPelt -- the part number is 864-6513. They should be a bit cheaper than the 185-Gs . . . and should perform just as well for your application.

B&S

[Bored&Stroked]

Reason for wearing out: Can be many things (like material/alloys of the lifters, etc). What you should ponder is the overall SIZE of the flathead performance profile . . . has a LOT less surface area (if you traced the path/length of a lobe) than a modern OHV engine and a much smaller base-circle - so you get more flex in the cam as well - which also wears things faster. Another thing to think about is that flatheads don't have rocker arms - so when you have a higher lift cam like a .425 Potvin, this would be .637 lift on a simple 1.5 rocker. So, to get higher lifts on a flathead, the profile has to be pretty aggressive . . .which also leads to more wear.

[Ol' Ron]

I use 50 lbs on the L-100 cam and turn it 5k. When we ran the 400 jr in the stock car we ran 65 lbs at one time we were running 85 lbs but the lifter were taking a beating. But that ea over 50 years ago and the oil is better now.

[frnkeore]

Originally Posted by Bored&Stroked

Another thing to think about is that flatheads don't have rocker arms - so when you have a higher lift cam like a .425 Potvin, this would be .637 lift on a simple 1.5 rocker. So, to get higher lifts on a flathead, the profile has to be pretty aggressive . . .which also leads to more wear.

You have to remember that I'm reverse engineering on this forum. This is my first FH build, since 1959-60 era and it was my best friends car.

In the case of the SBC (1.5 rocker) that .637 lift, would put a load of 450 lb on the lifter (300 lb spring) and the SB lifter, is only .843 in diameter and not able to take the same lift rate as a 1" FH lifter. Not to mention (I love that term) that springs for that lift, would normally be North of 380 lb. The FE's use a ratio form 1.72-1.75 but, a slightly larger, .875 lifter. With a .600 lift cam and 380 lb springs, that's 675 lb on the lifter and cam.

I only ask this, because , I've read, more than once, that you have to be careful of what seems to me, fairly low spring pressure or the cam will wear. I just got some hollow Hi Lift Johnson adjustable lifters and I want to make sure I won't have any issues. I'm hoping to have Howard's grind a Schneider 250F cam for this, unless that cam is available, off the shelf somewhere.

Most flat tappet OHV engines, use cast cams, are the early Ford cams, so soft that they can't be hardened to modern spec's and that is the reason they wear?

Frank

[JSeery]

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Everything in an engine that is moving consumes energy. You want the lowest valve spring pressures that will keep the valve train following the cam profile and avoid valve float. Flatheads don't require near the spring pressure of an OHV engine to accomplish that. And if you did float a valve it is not much of an issue.

Most of the metals used in early Fords are of high quality. I don't know anything specific about the material used in Ford cams vs modern cams, but would assume the early Ford cast cams would have been of high quality. Some flathead cams were steel, not cast and favored for some high performance applications.

Pete here on the Barn is a cam expert, he might have an input.

[Bored&Stroked]

If it was mine, I'd go with the LZ springs from Van Pelt and install them at about 2.0625 - should give you about 65 lbs on the seat . . . more than enough for almost any cam in the .375 lift range. I don't have the numbers for "on the nose" pressure . . . but it is probably closer to 180 lbs.

Flatheads don't have rockers or many moving parts - so we don't use a lot of spring pressure. There is really no need to run even 80 lbs on the seat - unless you're going to put some boost into it or rev it higher than 5500.

In my 32 Cab, I have a very stout street engine with a roller cam with .420 lift and very aggressive profiles, I run about 90 lbs on the seat . . . but that is also on a hardened 8620 billet and with a roller lifter - so I'm not worried about that sort of spring pressure wearing out the cam.

[frnkeore]

One more question, related to this issue:

Does anyone drill the hollow lifters to lube the cam lobes? If so, what size do they make the hole?

Frank

[flatjack9]

Never heard of it.

[Mart]

I'm not sure what you are referring to either. Is that a practice on some other motor? There is no oil in the lifter, so you can't feed the cam lobe from it. It all gets lubed from oil splashed from the rods.

Mart.

[frnkeore]

After hearing of the cam lobe failures, with higher pressure springs, it seems like it might cure that. You could also do it with solid lifters, by drilling a side hole, to meet the cam lobe face hole.

They would be easy to drill, with a 1/8" solid, carbide drill. 3/32" would be a a little harder to do and if you go smaller than that, you'd have to do it with EDM.

Just a thought, I'd be supersized if it hadn't been tried at some point.

[frnkeore]

Originally Posted by Mart

I'm not sure what you are referring to either. Is that a practice on some other motor? There is no oil in the lifter, so you can't feed the cam lobe from it. It all gets lubed from oil splashed from the rods.

Mart.

I was speaking, primarily about the hollow lifters. I just got some in the mail today. and while looking them over, I thought of it. Although you could do it with solids by drilling side holes to mate.

I can't think of the application, at the moment but, yes, it's been done before.

[JSeery]

But there is no reason to run higher spring pressure except in extreme competition and it those cases it normally requires a roller lifter or a wide based lifter. The issue is the small base circle and fast ramp rates.

[frnkeore]

Yes, high rpm was what I was referring to as that's where the high pressure springs are need BUT, I'm thinking of making my own guilds out of aluminum (bushing the EX with aluminum bronze) and using low pressure SBC springs and retainers (about 200 - 210 lb open) maybe even PC seals.

My engine won't go above 5500 though.

Why? Just because I can. Also, I can never stop thinking of why something works (or not) and always trying to improve, either by lowering weight, making it stronger or lasting longer. It's just how I've always been.

Frank

[JSeery]

Originally Posted by frnkeore

Yes, high rpm was what I was referring to as that's where the high pressure springs are need BUT, I'm thinking of making my own guilds out of aluminum (bushing the EX with aluminum bronze) and using low pressure SBC springs and retainers (about 200 - 210 lb open) maybe even PC seals.

My engine won't go above 5500 though.

Why? Just because I can. Also, I can never stop thinking of why something works (or not) and always trying to improve, either by lowering weight, making it stronger or lasting longer. It's just how I've always been.

Frank

That's a common trait amount Hot Rodders! With a flathead it's hard to come up with something that hasn't already been tried many times, just the way it is with these engines. There have been some wild and crazy things tried!

[KiWinUS]

So where is this magic oil in the lifters coming from? No modern engine here with pressure fed hydraulics

[frnkeore]

It wouldn't be pressurized but, threw the drilled, lifter adjusting holes in the lifter bosses. Using hollow lifters.

[Ronnie]

Yikes

[KiWinUS]

Great imagination but sorry not enough oil there period.
Good luck.
Cheers
Tony

[frnkeore]

Tony, how do you know that there isn't enough oil?

Would there be more oil transferred to the cam nose at it's highest spring pressure that way?

If you'd like to try, along with me, I'll drill your lifters for free.

The hot rod movement of the 50's was all about trying new, unproven things. Some failed but, some lead to where we are today and that includes reliable, NASCAR 9500 rpm engines.

Frank

[Bored&Stroked]

All the lubrication for the lifters, the lifter bores and the cam in general comes from oil being splashed or slung off the crankshaft. There is no oil being fed to the lifters. And yes, there are various folks who have drilled pressurized overhead lifters to feed oil to the cam - and there are roller lifters where pressurized oil is fed to the roller bearings . . . just no such concept in our flatheads.

Now, if you wanted to plumb the lifter bores for oil pressure and then build custom lifters to capture that pressure and feed it to the cam - can surely be done . . . but for what real purpose? At 65 - 85 lbs of spring pressure (on the seat) there isn't much use for it. BUT, if you can imagine it . . . it can be done . . . and if it makes your happy, I say go for it!

On our Flathead Cadillac Bonneville engine, we have full pressure to our custom lifter blocks and we feed the oil pressure to our roller lifters (which we made). The cam lifts .520, so having more oil for the rollers makes us sleep a bit better at night.

[Brian]

Frank, Please do not take offence, but I think you're overthinking a perceived problem. Before you get all carried away, ask on here if anyone has actually destroyed the lobes on a flathead. You say you've heard of this; where is the proof? By the way, ALL flatheads run hot, everyone knows that too! Not true, but seems to be a popular misconception.


You mention keeping components as light as possible; I too agree, and incorporate that concept as much as possible with my builds.However, it is my opinion, that if you beef up the spring pressure, this is exactly the same as adding extra weight to the valve assemblies. Many pounds of weight....
I use stock valve springs; the ones that are progressively wound, and find them more than adequate up to 6000 RPM.

[Brian]

Frank, Is this proposed Schneider 250F cam to go into your 37 block, and fitted into your 35 truck? With the heads modified to take 14 mm plugs? Or are you building another fire breathing monster?

[Tinker]

I run LZ springs maybe a bit much for a reground cam. Seems to be good so far. I have a fiber timing gear too. Keeping my fingers crossed.

https://www.jalopyjournal.com/forum/...prings.507288/


Drilling the valley valve bosses are to adjust adjustable lifters more easily. not for oil. If we are talking about the same thing....

My 221 has drilled bosses for easy lifter adjustment. Guess oil goes down there too from the valley also.


Less you have a extremely hot motor, you wont ever float a valve. Just my opinion.

.

[Bored&Stroked]

Here is some data on spring pressures - that I compiled via my own tests . . . will give you some ideas on options:

Flathead Spring Pressures
Author: Dale Hays, Vintage Horsepower, [email protected]
Date: 08/14/2019

The following was done with a hydraulic spring tester – have used it for quite a few years and it is quite accurate (until you get below about 50 PSI).

1. Isky 185G – Single Spring (new)

• 110# @ 1.900
• 100# @ 1.950
• 85# @ 2.00

2. Isky 185G- Single Spring (used)

• 180# @ 1.605
• 82# @ 2.00
• 50# @ 2.125

3. Iaky Dual Valve Springs (I don't use them on anything)

• 80# @ 1.765
• 180# @ 1.390

4. Ford 49-53 – 0BA-6513 (from Mac VanPelt)

• 60# @ 2.00
• 45# @ 2.125

5. Lincoln Zephyr – 86H-6513 (from Mac VanPelt)

• 82# @ 2.00
• 55# @ 2.125

So - if I was going to put say a .375 Potvin 3/8 cam in a street engine, I think I'd use the LZ springs from Mac and I'd install them at 2.0625 . . . should give me about 65 lbs on the seat. So there yah have it . . . . one more opinion to add to the mess! LOL

[flatjack9]

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Personally, I have never seen or heard of a flathead cam having a lobe wiped.

[Ol' Ron]

Thanks B&S, I was wondering what springs to use on the race engines, At one time I got LZ springs from JWL,but he's out of them. Also some LZ springs are mis- labeled stock springs. I measure the spring pressure at installed height And a .060 spacer works great on the stock long spring.

[Tim Ayers]

Originally Posted by Bored&Stroked

Here is some data on spring pressures - that I compiled via my own tests . . . will give you some ideas on options:

Flathead Spring Pressures
Author: Dale Hays, Vintage Horsepower, [email protected]
Date: 08/14/2019

The following was done with a hydraulic spring tester – have used it for quite a few years and it is quite accurate (until you get below about 50 PSI).

1. Isky 185G – Single Spring (new)

• 110# @ 1.900
• 100# @ 1.950
• 85# @ 2.00

2. Isky 185G- Single Spring (used)

• 180# @ 1.605
• 82# @ 2.00
• 50# @ 2.125

3. Iaky Dual Valve Springs (I don't use them on anything)

• 80# @ 1.765
• 180# @ 1.390

4. Ford 49-53 – 0BA-6513 (from Mac VanPelt)

• 60# @ 2.00
• 45# @ 2.125

5. Lincoln Zephyr – 86H-6513 (from Mac VanPelt)

• 82# @ 2.00
• 55# @ 2.125

So - if I was going to put say a .375 Potvin 3/8 cam in a street engine, I think I'd use the LZ springs from Mac and I'd install them at 2.0625 . . . should give me about 65 lbs on the seat. So there yah have it . . . . one more opinion to add to the mess! LOL

Interesting how the stock v. LZ @ 2.125" is a 10 lb difference, yet at 2.00", the difference is 22 lbs.

[KiWinUS]

Originally Posted by flatjack9

Personally, I have never seen or heard of a flathead cam having a lobe wiped.

I’m with flatjack. I have not seen or heard of this happening to a flathead cam stock or a hot rod cam.

[JSeery]

Maybe folks are confusing not requiring high valve spring pressure with can't have high valve spring pressure? Flathead era camshafts should be as good as or better material than more modern cams and new flathead camshaft blanks would be the same as any other new blank I would think.

[KiWinUS]

So just to let all know when I buy brand new Cam cores to grind to KiWi-L100 specs they come from the same company that has made “ALL” OEM cams for many many years so please don’t think flathead cams are an oddball.
Cheers
Tony

[Pete]

Originally Posted by frnkeore

One more question, related to this issue:

Does anyone drill the hollow lifters to lube the cam lobes? If so, what size do they make the hole?

Frank

Do NOT drill a lifter that runs on a performance cam. It will shorten the life of both the cam and lifter. I am not sure why but I have seen several over the years that tried and failed and I have been in the cam business 65 years.

You do not to need pressure oiling to the lobes or lifters on a flathead street engine.
On my race engines, I drill the cam core and lobes for pressure because these engines have dry sump oiling with high vacuum in the crankcase. This tends to suck oil off of all internal surfaces that are not pressure fed.

After market cast iron cam cores for flathead Fords are very poor quality.
The hardness varies down the length. They work for the most part but they are still junk quality. (Do not send me any to grind)

Valve spring pressures are not critical on flathead street engines with cams lifting under .380. Anything between 60 and 80 on the seat will have a 6000 red line and NOT wear anything out prematurely, and that is with no titanium valves or lightweight stock steel lifters.

I have seen quite a few wiped out lobes on flathead Ford cams over the years but they have usually been the result of broken springs or stuck valves, NOT from normal wear.

Hollow lifters DO run with oil inside on a wet sump engine. No additional holes needed in the lifter bore for oiling.

If you REALLY have to know what is going on with your valve train, leave the intake manifold OFF, hook the engine up to a variable speed electric motor and run it from idle to where the valves float while observing things with a strobotach. You will have to pre-educate yourself on exactly what to look for.

[Bored&Stroked]

Originally Posted by Tim Ayers

Interesting how the stock v. LZ @ 2.125" is a 10 lb difference, yet at 2.00", the difference is 22 lbs.

That is because the 'spring rate' is different . . .

[JSeery]

Pete, I have a question. Does the poor quality blanks apply to all aftermarket cams or just to the flathead cams?

[Bored&Stroked]

Originally Posted by JSeery

Pete, I have a question. Does the poor quality blanks apply to all aftermarket cams or just to the flathead cams?

It completely depends on where they were cast and/or roughed out.

I have seen some very poor quality cast blanks from one of the big manufacturer's . . . who supplies a TON of product to the various flathead cam grinders. Hardness is totally inconsistent and one would surely question the quality of the core materials.

I won't name names . . . but just think about the biggest name you see for high volume cams on a budget . . .

Me - I'd take a regrind on a Henry core over any of the new production cores . . .

[Pete]

Originally Posted by JSeery

Pete, I have a question. Does the poor quality blanks apply to all aftermarket cams or just to the flathead cams?

I don't know. I only do flathead Fords now.

[JSeery]

Thanks, just curious.

[frnkeore]

Thank you for the insight, Pete. I guess I'll by past the drilled lifter idea.

But, I have a question regarding valve oiling. I assume that because the FH valve is vertical, that with a good fit .001/.0015 in, .002/.0025 ex, that it wouldn't need valve stem seals?

The retainers that I buy, come with seals and 10* keepers so, if there is any benefit to running seals, I can add them.

I'm still planing on using 1.25 sbc springs, after researching yesterday, I found that the standard passenger car spring, closed, will be ~80 lb @ 1.75 and ~180, at 1.375. I can adjust the pressure a little after I test a set.

If you guys are wondering why I'm always re-inventing the wheel, it only because I love doing it and in this case (springs) it's about 1/4 the cost of Isky/LZ springs and retainers. The cost of the guilds is 0.00.

Frank

Added:
To answer B&S's question on page 1, I'm using 1.5 sbc ex and 1.6 in. Probably don't need the 1.6 but, I have them on hand.

[Pete]

"But, I have a question regarding valve oiling. I assume that because the FH valve is vertical, that with a good fit .001/.0015 in, .002/.0025 ex, that it wouldn't need valve stem seals?"

I have never used seals and never had excess oiling problems. I use solid bronze guides pressed in the block.

[GOSFAST]

The bronze guides are almost a mandatory item with us on all our FH builds, but we've never needed any 1-pc all bronze guides, we simply line the originals and machine them (intakes only) for some Viton stem seals. Not needed on the exhausts.

Here's another situation where the much longer Chevy valves create installed spring hgt issues. Been down this road more than 45 years now and have never used the longer valves. Really unnecessary?

With respect to the valve springs, the OEM pieces we supply to most customers yield 70# @ 2.060" with 130# at .375" lifts.

For some slightly higher performance builds we use the 185G's, these yield 85# @ 2.060" with 180# @ .375" lifts.

Most "streeter's" are fine with the lighter springs, they will take you to the 5000 RPM area easily.

Thanks, Gary in N.Y.

P.S. Here's a couple shots (again) of the bronze-lined guides, S/S valves, and seals. Also a shot of our very own design "adjustable" spring-seat hgt locators, allows the the use of up to (5) .060" shims plus the locator thickness (.060") and is still able to locate the springs!

[Bored&Stroked]

Frank - when you use a larger diameter spring than stock, you will not be able to assemble the engine the "easy way" - by dropping the whole valve, guide, spring and keeper assembly in from the top. You'll have to "assemble the springs" inside the valley area - which isn't a lot of fun and requires a set of tools designed for this specific task. It is by far easier to use Ford's method - where all you need is a good flathead "valve bar" and you don't have to worry about dropping retainers and keepers down into the bowels of the engine.

[frnkeore]

My guilds will be similar but, made of aluminum, with 1/2" aluminum bronze stock, drilled and reamed, pressed into them. I could put the PC type seals, directly on the bronze stock if, you think it helps.

I'm also considering a pressed in guild, with a shoulder, since I have to use 1 3/4 aluminum stock, to start with.

Does anyone use pressed in guilds?

Frank

Added:

B&S, I just saw your post after posting. I guess the pressed in guilds would go along with my spring use. Unless there a reason not to do it, I'll go with it.