Need help choosing valve springs?

[turbovanman²]

Ok, conicals aren't cutting it for high boost, after a big discussion with the mods, we came up with there probably costing my HP, seat pressure is 60 lbs vs stock at 105, open is 170 vs stock at 160. Sooooooooooo, what to use boys and girls. Mp lists 3 sets,
P4286813- wire diam .186"
P4876061- wire diam .191" this is the S60 spring.
P3412068- wire diam .191" dual damper.

The last 2 need special retainers????????????

Anyhow, are these any good or what other options?? I also notice the Slant six and 3.9 V6 use the same valve spring so that means probably the Magnum V8 springs might work!

Ok, lucky me, I remembered I had some MP 318 valve springs, dual damper. There 120 seat and 240 open. There good to over .500" which is good as the stockers are almost at coil bind at my S2 lift of .469

They also list retainers, chome moly which I assume are stock, then the aluminium ones and of course, titanium. Is it worth it to get the last 2? now I don't have to buy springs, I can use the money for those. The al ones are $16 each and the titan are $26 each?

[Whorse]

I think you answered your own question.

[turbovanman²]

Bump on the retainers, stock or chromemoly or are they one and the same?
Does anyone know if they are different, if the chrome weigh less?

[Frank]

Whats the cost difference?

[turbovanman²]

Well, the stockers are free, the chromies are $12 each and the titaniums are $30 each,

[Clay]

I thought you were going with the 302 springs???

[ssheen]

Why do you think they are costing you HP?

[turbovanman²]

I thought you were going with the 302 springs???

No, I am using the 318 MP springs. Just need an opinion on the retainers,

Why do you think they are costing you HP?

The experts have told me that the spring pressure is way to low, the boost is forcing the valves open, this is costing me power. Stockers are around 105 closed and the conicals are 60 psi so thats a big difference.

[ssheen]

ah, I understand the idea. Not too sure I see how even 30psi of boost can cause a valve held shut with a 60psi spring to open? Perhaps it slows it from closing?

[turbovanman²]

ah, I understand the idea. Not too sure I see how even 30psi of boost can cause a valve held shut with a 60psi spring to open? Perhaps it slows it from closing?

Theres a formula to figure it and its quite possible, some of the pro's, ie Steve M have had it happen. A valve is X amount sq inches, multiply by this, apply that etc and it can get held off its seat or against seating easily.

[Frank]

mostly the case of not closing... bacially fluttering shut. Also remember that 60psi isnt a good way of looking at it... 60lb/in which means 60lbs to move 1 in.

Now seat pressure is 60lb/in. The actually spring is higher, but still below stock up until you get about .25" of lift, then it goes past... not really benificial at that point.


Frank

[Frank]

Theres a formula to figure it and its quite possible, some of the pro's, ie Steve M have had it happen. A valve is X amount sq inches, multiply by this, apply that etc and it can get held off its seat or against seating easily.

I can't wait for you to drag race again to see results

[turbovanman²]

I can't wait for you to drag race again to see results

Thanks but its gonna be awhile,

[ssheen]

Thanks for the info. I assume the effect is different with large valves over stock? What level of boost are we talking about?

[turbovanman²]

Thanks for the info. I assume the effect is different with large valves over stock? What level of boost are we talking about?

I would assume 15 psi would be the limit on the conicals but I am running 25psi now and plan on 30-35psi to achieve my goals.

[Directconnection]

... 60lb/in which means 60lbs to move 1 in.
Frank

I think you mean 60lbs to move a 1" diameter? like as in a hydralic or pnuematic piston. 1" reffering to the surface area. Or, 60lb an inch like a lever arm of 1". But, once the piston is in motion, it should stay in motion, and not travel a one inch distance only.

Anyways.... 60inlbs is agreed that it sounds awfully low for this application. Anybody know what a TBI spring has for a seat pressure? I could test at work, but I have a "Bag 'o 2.2/2.5 valve springs" and not knowing what's what

[turbovanman²]

No idea, I have a bag and box o-valve springs,

[puppet]

Why do you think they are costing you HP?

All valves bounce off the seat when they close ... even with heavy springs. The difference is that at high rpm's with a heavier spring that bounce is controlled. Lighter springs allow the valve to bounce uncontrolled, rebounding up and down and side to side, till they finally seat. Light springs can also damage the valves/seats over a short time.

They're good for breaking in some cams but once that's done heavier springs should be swapped in. Heavier the better.

[JDAWG]

I think you mean 60lbs to move a 1" diameter? like as in a hydralic or pnuematic piston. 1" reffering to the surface area. Or, 60lb an inch like a lever arm of 1". But, once the piston is in motion, it should stay in motion, and not travel a one inch distance only.

Anyways.... 60inlbs is agreed that it sounds awfully low for this application. Anybody know what a TBI spring has for a seat pressure? I could test at work, but I have a "Bag 'o 2.2/2.5 valve springs" and not knowing what's what

I show all 782 heads having the same springs. Now the older heads (I guess G heads) I show 2 completely different springs for NA and turbo. 4.24mm dia for NA and 4.5mm dia for turbo. And why these springs are different part #'s then for a 782 head I really have no idea. If all the springs fit for the 782 head than why not a G head? And why in the MP book they dont list any differences in the springs between G and 782? Well just remembered G head valves are taller, but I guess springs will fit both? Oh and Simon dont know what year MP book you have but one on fthe ones I have shows the 2.2/2.5 and slant six/3.9 on the same section and the 813 springs is listed for both engines so yes magnum stuff could be used also. Well just flipped to the magnum section and none of the springs are the same but the 032 moly retainers are listed for the magnum engine and 2.2/2.5 but not the slant6/3.9?? I dunno but I say the magnum stuff will work.

[turbovanman²]

^Thanks, my book is the same. I am not worried about the 318 springs, but the difference in retainers. I just ordered one Chrome retainer, same weight as the stocker so that saves me $100, will just reuse the stockers. I would like the titanium ones but not at $26 each.
I have been looking at V8 ones but there all the wrong keeper angle, we have 8 deg locks and most V8's are 10 degs. The V8 sets are around $250 for 16. I would glad split it with someone but I don't know if the 2 deg difference is bad or not? thoughts?