Comp 910s

[97spoolinstroker]

Hey guys I'm in the middle of putting my 7.3 together I'm running a s366 2.5 charger and ganna be running 300/200s do you guys think 910 valve springs will be fine or should I also shim them to get them alittle tighter


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[JD3020]

I used a .060 shim on mine, put me somewhere north of 130lbs of seat pressure. I've ran it hard with a ton of boost and back pressure and not a single issue. If you don't shim them they are just a hair better than stock springs.


And why a S366, seems pretty small for those injectors.

 

[m j]

wastegate?

 

[Magnum PD]

S468

 

[Groomzybanshee]

I didn't shim mine. Prolly had 30k street miles an 25 hooks with several revs to 4-5k. Pistons didn't have any marks. My dd prolly has 80k miles not shimmed still good.

 

[GreenF350]

I did shim mine. I set the installed height to 1.780" and if I couldn't get it exact, I went to the next bigger shim. I would rather have them a little higher seat pressure than have contact (Avoiding coil bind of course). Couple thousand miles on them and so far, so good.
-Aaron

 

[Derek@Vision Diesel]

If your going to shim...please check the installed height.

Going by a seat pressure estimate is foolish.

a wrong guess and you will have broken rocker arms in your future.

 

[Dieselboy.]

Don't go over 125lbs on the seat either.
Installed height is a better way to go. But I did the math and a .045" got me to 125lb. Matt@gearhead said anything on 910s over that just wears the spring out prematurely.

Just his opinion. But he might know someone go knows somebody that knows a thing or two about 7.3s

 

[GreenF350]

Don't go over 125lbs on the seat either.
Installed height is a better way to go. But I did the math and a .045" got me to 125lb. Matt@gearhead said anything on 910s over that just wears the spring out prematurely.

Just his opinion. But he might know someone go knows somebody that knows a thing or two about 7.3s

Hmm...Interesting. I'd say he probably knows a thing or two about a thing or two. :thumbup: I am a bit over that seat pressure on most of mine, but just a bit. Hope they hold out because I'm not redoing them.
-Aaron

 

[Milford]

So would it be worth going with something a little better then a 910 that is shimmed? I'm about to buy some parts also and was wondering the same thing for pretty much the same setup. There are so many choices for springs out there now with 910s being the cheapest and most basic.

 

[bigfords]

I didn't shim mine. Prolly had 30k street miles an 25 hooks with several revs to 4-5k. Pistons didn't have any marks. My dd prolly has 80k miles not shimmed still good.

How many miles were on the pulling truck before you put the springs in it?

 

[Rideracelivemx7]

If your going to shim...please check the installed height.

Going by a seat pressure estimate is foolish.

a wrong guess and you will have broken rocker arms in your future.

thank you! i made this same mistake my first time around, a very knowledgeable friend pointed it out to me after i reviewed my math with him. i completely neglected the installed height. Given i was with in spec but these injectors and turbo i was pushing the comfort level for what was left AFTER full decompression and adjusted height for 130-132lbs of seat pressure. i think the comp 910 has 1.280" before coil bind. when you have 1.78~" of installed height and a powerstroke cam having a lift of what ever it was(cant remember but not super impressive) left like .015" for margin. These arent exact specs but from what i remember it was pretty alarming assuming max power/boost/pressures and boom, hung valve and bent pushrods/rockers.

However there are a TON of us on here that get away with some pretty heavy abuse on the 910 springs including myself. I beleive i ended up with 115LBs of seat pressure using a .015 shim/silver shim

 

[Rideracelivemx7]

little more info COMP Cams#249-910-16
Single Outer Valve Springs
Rate: 458 lbs
.930'' ID, 1.354'' OD
Seat Load: 94 lbs at 1.850''
Open Load: 323 lbs at 1.350''
Coil Bind Height: 1.280''
With Damper
16/pkg

 

[GreenF350]

Valve lift is just under .400" at the valve from what I was able to find. I set mine @ 1.780" or the next step tighter since my smallest shim was .015". So 1.780 - .400 = 1.380". Coil bind is 1.280 on 910's so that leaves about 0.100" or a bit more. Mine has been driven about 6k miles since the install and no valve train problems yet.
-Aaron

 

[liquidlounge]

So would it be worth going with something a little better then a 910 that is shimmed? I'm about to buy some parts also and was wondering the same thing for pretty much the same setup. There are so many choices for springs out there now with 910s being the cheapest and most basic.

Exactly....spring technology has really advanced for the consumer in the past 5 years or so. With some of the new materials, treatments,and shapes they are doing things with springs now that last hundreds of hours that used to be good for less than a race. The comp springs are at the economy end of springs. They work ok because of the low lift/low rpm application.

 

[neverkickn]

If your going to shim...please check the installed height.

Going by a seat pressure estimate is foolish.

a wrong guess and you will have broken rocker arms in your future.

How exactly can one estimate the seat pressure without measuring spring height? Seat pressure is a derivative, therefore one can't possibly begin to guess what it might be without measuring first.

 

[Milford]

Exactly....spring technology has really advanced for the consumer in the past 5 years or so. With some of the new materials, treatments,and shapes they are doing things with springs now that last hundreds of hours that used to be good for less than a race. The comp springs are at the economy end of springs. They work ok because of the low lift/low rpm application.

That's how I sit on the whole valve spring opinion. Everybody says 910s are fine but my whole thing is what about the next step up? Would the extra 100 bucks be worth it and possibly get a longer lasting stronger more durable spring? What about the Irate ones, Swamps, ect, ect, ect. So many to choose from yet so little real life info on them, just what the website for the vendor says.

 

[gnxtc2]

The next step is to remove the heads and machine the spring pockets to accept a different size spring. The 910s fit with no mods and that's what makes them a popular choice for the 7.3s.

The proper way to install springs is with a mic and then add the correct shim. I cringe when I hear guys installing shims w/o measuring them.

I'm not a fan of Comp springs and run PAC springs on my race car.

Billy T.
[email protected]

 

[gnxtc2]

thank you! i made this same mistake my first time around, a very knowledgeable friend pointed it out to me after i reviewed my math with him. i completely neglected the installed height. Given i was with in spec but these injectors and turbo i was pushing the comfort level for what was left AFTER full decompression and adjusted height for 130-132lbs of seat pressure. i think the comp 910 has 1.280" before coil bind. when you have 1.78~" of installed height and a powerstroke cam having a lift of what ever it was(cant remember but not super impressive) left like .015" for margin. These arent exact specs but from what i remember it was pretty alarming assuming max power/boost/pressures and boom, hung valve and bent pushrods/rockers.

However there are a TON of us on here that get away with some pretty heavy abuse on the 910 springs including myself. I beleive i ended up with 115LBs of seat pressure using a .015 shim/silver shim

Prior to me installing my 910s, I did my calculations also. Bringing a spring to coil bind, severely shortens its life. You want to be within .050 of coil bind. To this date, I can't find what the rocker ratio is which is an important part of the calculation. The shop manual has the cam lift but don't recall if it is total lift or just lobe lift.

Billy T.
[email protected]

 

[littleredstroker]

I went 1.750 with mine. have probably 10k miles on it now with no issues