What spring rate should I set with stock springs and an 8CM camshaft

[1951 Ford F3]

I am having a hard time deciding on valve springs for a Merc rebuild. I just ordered an 8CM camsahft from Delta. The specs are 208 effective at .050 with a .338 lift.

I ordered some Isky 185 G springs, but they are way to stiff. I then ordered a fairly nice valve rebuilt kit, however, the springs tested at 26 pounds installed height and less than 100 at coil bind. Needless to say these are tractor springs.

So, I want to keep the rest of the kit, but need good stock valves that are at least 60 pounds at 2.00 installed height or (1.940)

I saw that Van Pelt has a nice valve rebuild kit and also stock springs that are about 50 pounds at 2.125.

I could just regrind my original valves and reuse the springs

What say yee

[tubman]

Why do you say the Isky 185 springs are "way too stiff"? I have used them with an Iskendarian "MAX-1" which is not much more than an 8CM with no problems.

[1951 Ford F3]

Originally Posted by tubman

Why do you say the Isky 185 springs are "way too stiff"? I have used them with an Iskendarian "MAX-1" which is not much more than an 8CM with no problems.

It doesnt nee that much spring... An 8CM is considered stock. With a .060 shim, the stock new OEM spring will be perfect.

[tubman]

I still think the Isky springs will be fine. If you ain't gonna use them, I can take them off of your hands.

[tubman]

I still think the Isky springs would be fine. If you ain't gonna use them I'll take 'em off your hands.

[macdonge]

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Ditto what Tubman said. I’m using the same setup he described with no issues.


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[Bored&Stroked]

The Isky springs will work fine, though they will have a lot more spring pressure than you'll need. The more spring pressure you have, the more wear on the cam over time. You might consider checking with Mac VanPelt or Thirdgen and see what they have? I'd probably get a set of Lincoln Zephyr type springs and run about 45 lbs on the seat. Unless you're going to really rev it up, that is all you need.

[1951 Ford F3]

Originally Posted by Bored&Stroked

The Isky springs will work fine, though they will have a lot more spring pressure than you'll need. The more spring pressure you have, the more wear on the cam over time. You might consider checking with Mac VanPelt or Thirdgen and see what they have? I'd probably get a set of Lincoln Zephyr type springs and run about 45 lbs on the seat. Unless you're going to really rev it up, that is all you need.

.
I am going to have new seats installed along with new valves. My guess is that the installed height will come in well below 2.00 inches. I had an engine shop for 10 years. I know about wear from to much cam duration and spring rate. As a VW aircooled drag racer that can run the 10.80 class, I know all about lifter compatability etc. That is why, I would rather shim stock springs for maybe 55 to 60 on the base circle and what ever it gives on the nose.

New springs with a high silicon content and shims will provide a really good valve return.


On another note, I have ordered an 8CM regrind from Delta, however, the cores are still in transit . The motor will be a 4 inch by 3.312. I have ported the block. The heads will be EAB surfaced for .040 over the dome. I am wondering what your thoughts on cam selection is. I thought of the 8CM, 1007B, and Max1. I will be running dual strombergs with 43 jets and 69 PVs. What are your thoughts on cam selection, valve springs, jet size and power valves along with distributor selection. I will be running stainless 1.5 valves and quality guides. I would like to know what cam selection is going to suit this engine for around town running and freeway cruising. i build all my own motors. Just tell me what cam gave you the greatest ooooooh aaaaaah effect and best power and driving experience without regard for drag racings etc. Everybody has an opinion based on other peoples opinions. Since you have built motors, what was your most impressive smaller cam experience.

I am not opposed to Isky springs. However if the seats come in to high, I will probably see 1.940 installed height. At that point, I should just run 236 effective at .050 and a .355 lift. I will get ahold of Van Pelt on Monday and see if he has those really good stock springs that are 45 pounds at 2.125.......... What say yee???????

[tubman]

We need more information. Cam selection is as much about vehicle type and intended use as it is about engine modifications.

[1951 Ford F3]

Originally Posted by tubman

We need more information. Cam selection is as much about vehicle type and intended use as it is about engine modifications.

This is the entire build:

1951 Ford F3 torch red
Borg and Warner 5 speed conversion
Mercury Mountainier 3.73 disc brake rear end
Speedway disc brake kit
Power booster
Cragar SS modern muscle rims

I have 2 good blocks and will eventually build both.


1950 Merc block "ported"
EAB heads surfaced to .040 above piston dome
2 each pristine cam cores
Ross pistons 3.312
possible Scat H beam rods
Merc crank
stainless steel 1.5 valves
SBI guides
rebuilt M-19
dual Stromberg 97s
modified mallory dual point

I have two blocks, 2 cranks, and 2 sets of EAB heads. I also have a 4.125 stroker crank

I am ready to pull the trigger on Ross pistons, scat Hbeam rods, 185G springs and a camshaft that would be the best for a street truck.

I ran an engine shop for 10 years before being activated for Iraq in 2003. I shut my business down over 20 years ago and worked on my houses etc.

I built a shop in Colorado and moved most of m tools from my engine shop in Washington.

am going to build 2 motors. The piston selection these days is limited to Ross forged with metric ring pack. I dont know if I want to use the 2 sets of stock rods that I have or buy some scats. I am down to what cam to use and what springs to use for a 9 to 1 engine. The first build could be a 276 hotrod engine with a bigger camshaft. However, I am not certain if it would be prudent to run the stock 8CM or a bigger cam like the MAX1 or 1007B.

These are simple questions. Like I said, I ran my own engines shop and building a flathead is not rocket science or difficult. Just want the skinny on cams and available springs like Van Pelt has..
The machine shop says to run a Max 1 and call it good
The OL Ron dude swears by stock springs and a .060 shim.
Bored and stroked says Van Pelt has some stock springs. Goodson has shims for $25

I will call goodson and see what they have in the way of stock springs as well. Qualcast may have a flathead spring

What say yee?












s

[Ol' Ron]

Try a .060 soacer under the 26 lb springs 45 is more than necessary on a stock engine/
Gramps

[1951 Ford F3]

Originally Posted by Ol' Ron

Try a .060 soacer under the 26 lb springs 45 is more than necessary on a stock engine/
Gramps

That is not possible. It doesnt get to 45 pounds until well after 1.800. At coil bind, it barely hits 80. These arent even close to being OEM spec.

I will call Goodson and see what they have. I am looking for at least 60 0n the seat.