solid flat tappet camshaft spring pressure needed

hey there
i have a solid flat tappet camshaft and its a @50 dur 259/266 lift .632/650 lsa 109.5 would like to know what springs i should run with these i have d2oe-ab heads ported and have 2.22 and 1.75 valves useing a 1.73 rocker right now the springs in the heads are for a solid roller cam .647 lift i am not sure the pressure of these springs i am going to buy a spring tester
if someone could chim in thanks

I would look into the Comp Cams #930. #370 open. That's what they list for solids in that range.

If you want a little lighter they list #924 for the street solids up to .640 lift at #315 open. It would be borderline in my opinion.

#928 for a 1.880" installed height at #370 open.

They list a 938 at #540 open for a roller cam in that lift range.

Many other choices out there though. These are general Comp. Cams book springs for their 429/460 cams.

You can check them out on page 96 and 295 if you like. They changed the ratings up a tad from the old book numbers I listed above. Same part numbers though. Looks like rated at different lift.

https://www.compcams.com/master-catalog

any idea what pushrod length i should order or wait till i install cam and measure it out i am sure guys have a idea what to run
thanks Brad

maverick172 wrote:hey there
i have a solid flat tappet camshaft and its a @50 dur 259/266 lift .632/650 lsa 109.5 would like to know what springs i should run with these i have d2oe-ab heads ported and have 2.22 and 1.75 valves useing a 1.73 rocker right now the springs in the heads are for a solid roller cam .647 lift i am not sure the pressure of these springs i am going to buy a spring tester
if someone could chim in thanks

I have used the PAC-1903 many, MANY times with flat tappet camshafts around this size; or the Comp 928 if you want a little more seat pressure

I put the CJ/Marine spring pads on my PI heads. Do you have them on yours? I would check and see what the installed height is now as a guide between the 928's and 930's, if it came to using them.

Same as above, measure for your pushrod length after your get the cam in. Sometimes the blocks are cut down .030" and the heads shaved .010" or more, along with differences in rocker arms, so you are best off to check.

I'd assume those solid roller springs will be too stiff. I'm running a very similar custom SFT cam 258/262,6.55/6.55,110. When I bought the cam I ordered from the same company matching springs,retainers,locators and keepers that were speced for the cam to fit the SCJ head I was using. Not sure what brand they are but measure 1.88 installed height and 125/325 lbs which I verified in a spring tester. It was nice fit,all were almost exactly the same lbs and installed right at the correct height with no shims. My MSD has a 6200 chip and I have not had an issue,feels like it wants more RPM when the chip kicks in. I adjust the valves in the spring and have had almost no increase in lash since the first couple checks after the initial install a few years ago. I'm relieved and pretty happy so far. I know everybody has their own oil preference but the oil recommended by the cam supplier was Valvoline VR1 20W-50 and for warranty purposes on the cam/supporting parts I used it,still do. So far,so good.

the tree man wrote:I'd assume those solid roller springs will be too stiff. I'm running a very similar custom SFT cam 258/262,6.55/6.55,110. When I bought the cam I ordered from the same company matching springs,retainers,locators and keepers that were speced for the cam to fit the SCJ head I was using. Not sure what brand they are but measure 1.88 installed height and 125/325 lbs which I verified in a spring tester. It was nice fit,all were almost exactly the same lbs and installed right at the correct height with no shims. My MSD has a 6200 chip and I have not had an issue,feels like it wants more RPM when the chip kicks in. I adjust the valves in the spring and have had almost no increase in lash since the first couple checks after the initial install a few years ago. I'm relieved and pretty happy so far. I know everybody has their own oil preference but the oil recommended by the cam supplier was Valvoline VR1 20W-50 and for warranty purposes on the cam/supporting parts I used it,still do. So far,so good.

Intended use and RPM ceiling is something to consider.

When trying to compare these springs I look close at the measured heights. Comp Cams changed theirs and other company's use other heights. Interesting when you start comparing the spring rates also. The Comp. 924 at 1.880" is 125# and at 1.280" is 315# in the old Comp catalog. It is about the same as yours.

The PAC's 1903's has the highest spring rate of the others mentioned at 391, with 120# at 1.875" and 394# at 1.175". Like Randy said the 928's and also the 930's do have more seat pressure. The 928's are 160# 1.880" and the 930's are 150# at 1.920" installed height in the old book, everything else between them measurement wise is the same. It seems like almost the same spring with two part numbers or the 930's are wound for longer valves.

If it's for street cruising the lighter ones get by. For racing or frequent high RPM use I would stick with the heavier ones. They will last longer.

https://www.racingsprings.com/index.php/valve-spring-11325.html

I always liked the VR-1 20W-50 also.

maverick172 wrote:any idea what pushrod length i should order or wait till i install cam and measure it out i am sure guys have a idea what to run
thanks Brad

See if you have 8.550"s now? That's pretty much the Comp Cams go to length for both cams similar to yours. If not try the ones you have and see how they look on the valve tips through the cycle.

thanks for the replys i think i got it ironed out now .ya thinking of going to a 15w40 oil and in the real hot summer 20w50 or best to stick to one grade? ya i do have the 8.550 pushrods now , but as to how the geometry was i am not sure i never built the engine originally but i will be checking for sure

I have never heard of changing weights being a problem. I always ran the 20W-50 year round but, it does not get very cold in the winter here.

I don't know if you got lifters yet but, I believe this is the new hot ticket Johnson's that are supposed to be good.

https://crower.com/lifters/lifters-by-engine/ford-221-302-v8/mechanical-johnson-flat-tappet-lifter-ford-240-300-221-460.html

supervel45 wrote:I put the CJ/Marine spring pads on my PI heads. Do you have them on yours? I would check and see what the installed height is now as a guide between the 928's and 930's, if it came to using them.

Same as above, measure for your pushrod length after your get the cam in. Sometimes the blocks are cut down .030" and the heads shaved .010" or more, along with differences in rocker arms, so you are best off to check.

The 928 and 930 is virtually the same spring but, from different vendors; one more expensive than the other.
Personally, I can not tell you which one gives better service.

rmcomprandy wrote:

supervel45 wrote:I put the CJ/Marine spring pads on my PI heads. Do you have them on yours? I would check and see what the installed height is now as a guide between the 928's and 930's, if it came to using them.

Same as above, measure for your pushrod length after your get the cam in. Sometimes the blocks are cut down .030" and the heads shaved .010" or more, along with differences in rocker arms, so you are best off to check.

The 928 and 930 is virtually the same spring but, from different vendors; one more expensive than the other.
Personally, I can not tell you which one gives better service.

Both springs jobber for $169.67. Sometime, over the decades, someone at comp told me they were the same spring. One sold for 1.88" install and the other for 1.90" installed height. Maybe it's different now but, that's the way it used to be.