WHAT VALVE SPRINGS FOR #041 CAM?
 

Looking for input on what valve springs to use for a #041 cam. I have a d-port 455, 4 bolt main, 10:1 comp, 1.65 rockers, 4:10 gear, small 28" tire will likely see 6200 rpm+.

Also what are the best valve seals & retainers? Thanks!!

Spring choice completely depends on the specific installed height of your given set of heads,without that info we cant help you much beyond generic suggestions.

Seals,most prefer to use the viton PC style seals,IIRC pioneer makes those,heads often need to be machined for these seals.

Retainers,those often depend on the spring choice.

If were talking about a set of basically stock iron heads,that are using stock length valves,and the OE appx. IH of 1.60",then the best choice IMHO is the crower #68404-16 springs and corresponding retainers #87048D-16.

If using some longer valves (+.100") and the taller 1.70" IH,then I use the crower #68405-16 springs and the same Crower #87048D-16 retainers.

Though I suspect you'll have a challenge getting that hydraulic cam deal to rev to 6200 RPM's consistently,I usually go to solid cams/lifters for anything expected to regularly go more than 5500 RPM's myself.

JMO/HTH.

6200 on a 3.25 main. i would be just as concerned about the oiling system as i would be the valve springs. if you are going to be working with an installed height of 1.65 or greater i would recommend the comp 995's.

rex

Comp 995's have their own set of issues,and those issues have been discussed here already a bunch,do a search if you want/plan to use those springs and heed that advice,and with the 995's you absolutely need to check the spring pressures on those springs before using them,or you might just get a unwelcome surprise.

And understand that the current batches of 995's are strictly for 1.700" IH or taller,if you install a set of them @ 1.65" I can all but guarantee the pressures will be way too high for most any flat tappet use.

Comp 995's also require some machine work to fit the pontiac iron heads,and they absolutely must use small diameter VS seal to fit inside them,the OE positive style seals often wont fit inside those springs.

Lunati has a good spring that installs @ 1.65" if that is what you need,part #73949 IIRC.

HTH.

Correct, the last set of 995's that were brought here checked 160lbs on the seat at 360lbs over the nose, a bit much for the RAIV camshaft. They also came with retainers and 10 degree locks. Any spring used must be checked with the retainers you are going to use, as the inner step not only effects spring pressure, it also effects coil bind of the inner spring.

The dampner used with the 995's should be smoothed out where it contacts the head/shims, as they can/will cut into the shims and put metal in the assembly. They are well made springs, but not a "drop-in" for the Pontiac heads. We prefer and use the 68404's and 405's listed above, excellent direct replacment springs for high lift cams.

We've used the 68405's with HR to lifts as high as .624", no problems. They can also be shimmed to 1.650 for flat solid cams.......Cliff

my bad, i am using them in a solid lifter application.:o

cliff,
whats the deal. i had to have mine shimmed to 1.630 to get 140/350. this was done by a experienced cylinder head guy using a rimac machine.

Comp 995's? Keep in mind that the retainer used effects the spring pressure, and we did not purchase these springs, they were supplied with a set of heads we were asked to set-up. I tossed them aside and used the Crower 68405's instead......Cliff

68405's seem to be more consistent too. Also the keep their installed pressure over a longer period of time at least that is what I have observed.
Ken

Thanks!
 

Thanks for your help guys! I will go with the crower springs & retainers, once I check the IH, to determine which # to use.

I am also a bit concerned about oiling! Though This 455 has warrior billet 4 bolt main caps & a SD 80 psi oil pump & 74 SD rods ( I know, too high psi, this is the way I bought the car ).

There likely is no reason to have a 4:10 gear in this car & turn 6200 rpm+, as I will always run a stock 26" street tire. No porting on the stock 72' d-port heads & #041 cam, I wonder what rpm I should shoot for through the traps? & what gear, maybe a 3:73 or even a 3:55? For this year I will be racing with the 4:10.

Any reccomendation for a good quality mech. fuel pump? Need no more than6psi for my Q-jet.

Thanks again guys!!

The older 995's were a completely different spring,Comp changed the seat and open pressures completely,and instead of changing the part number to reflect that,the new specs just superceded the old specs,if those pressures are what you measured,yours are likely the older stock 995's.

The "new" 995's are listed as 130 lbs @ 1.700" and 372 @ 1.150",and like Cliff says,they often measure more as SOP/OOTB as they'll loose a few lbs after a bit of run-in time.

The "old" 995 specs were 115 lbs @ 1.700" and 340 @1.150",and from what I know of this deal,those "old stock" 995's usually check right at those specs,or a few reports stated they might check in just below that.

Like I said,those springs have been discussed a bunch here already,and I was hoping that there was no need to spend time re-typing all that info here,do a search on 995 and you'll get all the info.

And as for the lunati #73949 spring,I'm not entirely sure it's not the same spring as the crower #68405-16 spring,with lunati just listing that #79349 spring at the 1.650" IH instead of 1.700",those lunati springs are rated as 120 lbs. @ 1.650" and 265 lbs. @ 1.250" their CB height is listed as .950" and the rate as 363 lbs.

The Crower #68405-16 is rated at 129 lbs. @ 1.650" and 278 lbs. @ 1.250",CB is .980" and their rate is 382 lbs/in.,so those two part numbers are very close to each other according to their ratings.

As stated for "healthy" applications most will install the Crower springs @ slightly less than the 1.700" IH,mine were installed @ 1.687" and that got 115lbs.,this set-up is good for up to .630" lift easy while leaving the proper retainer to seal clearance.

That was with +.100" ('67 to '70 5.100" appx.) length valves in #96 heads.

I'm going to be using the Crower #60210 hydraulic with those #96 heads,and that Crower hydraulic is somewhat close to the .050" specs of the OE 041/RAIV hyd. cams,except that it has slightly more lift,less seat duration,and a tighter LSA,all for a bit less total overlap than the 041 cam has (yet more OL @ .050").

And FYI I'm using a set of HS 1.65 roller rockers with this cam for a lift of .531"/.551" (.547"/.567" if you consider the HS 1.65 rockers measure closer to 1.70 ratio) based on the .322"/.334" lobe lift.

Though those #96 heads were originally set up to be used with a Crower custom solid cam #E-27941,that solid cam is 256°/260° @ .050" and had quite a bit more lift than the current hydraulic has,and the solid was intended to be run with the 1.65 rockers as well.

That custom solid cam has a lobe lift of .360"/.365".

That custom Crower solid cam found it's way into my racecar's 406 instead of the streetcar's 455,that 406 engine uses the "old" spec 995's @ 1.700".

As you can see,the old spec #995's are very similar to the specs those #96 heads were set-up to use with the #68405-16 Crower springs and that #E-24971 custom solid cam,so that was a natural choice given the parts I already had on hand,that 406 engine had a comp 292 magnum hydraulic when I got it,and I'm not a fan of that style of grind,so in went that solid cam!!!

The race engine is intended for higher RPM's,as it has the better bottom end (eagle rods/forged pistons) and it will see regular use over 6000 RPMs,the "street" 455 on the other hand has a cast bottom end,so it will never see over 5400 RPM likely,thus it got that hydraulic cam to act as a defacto "rev-limiter" of sorts.

I'm practical to a fault at times,this is just an example of that.

HTH.

Shoot for peak hp at the end. With a 4.10 gear and 041 cam you will hit peak hp WAY before the end of the 1/4. My old set-up(455/041) dynoed peak hp at 5300 rpm. JMO but it will just not pull to 6200. You need to go to a larger cam or swap in a different gear, with a 4 series carrier(12 bolt?) the highest gear that will fit is a 3.73. Please do not take this wrong, I am just trying to help. -Jim

It's a proven fact of the 041/455 combo's, shifting above 5400-5600 max does nothing for performance. All you would do is over rev the peak power of the engine possibly causing damage. Do some searches on the setup there are many examples. Way back when Jim Hand had this setup in his wagon he shifted at 5200 rpm for best track performance. Good luck! JD

P.S. Crower springs all the way!

041 cam
 

Run comp 995 springs.
To gain power run an Ultra-Dyne 288/296h10
Worth 40 to 45 more horse over the 041.
Power brakes will work too.

You can see all this stuff on my web site:

http://www.pontiacengines.net

Pontiac Gregg