valve springs SBC (boat)

[mongo]

what size valve springs do i need for iron eagel p heads my stock z28 springs look too small for machined seat? 1.250? 1.437? 1.550? these heads are for 5500rpm boat w/miled cam.

[Dart Vader]

Are you using a stock hydraulic flat tappet cam or upgraded hydraulic roller?

[mongo]

mr dart i am useing a very mildedcam. 1 up from stock.It is a flat tappet cam 112center w/ roller rockers 1.5
thanks MONGO

[Dart Vader]

You will want to use the 1.250 spring for that good sir!

[mongo]

are you sure 1.250s is what i should use? spring pockets look too big & the springs seam to move around a lot
thanks agian mongo

[Awesome Bill]

what size camshaft? lift wise, and what RPM will you be running.?

[Dart Vader]

Those heads are cut for 1.250 - 1.437 springs, so a little movement is ok.
The 1.250 springs should work fine for you, I checked this with our boat guy here and he felt they were the right springs.
If there is anything you are wondering about though, don't hesitate to ask. You can even give us a call if you want to talk at length about it.

Hope this helps!

[want-a-be]

The valve guides will keep the springs located properly.

Don

[Awesome Bill]

Never run a spring with any type of side to side movement, this cause wear on the surface of the heads and will eat valve spring shims up. The head should be step cut for the 1.250 and then 1.44 spring package. If your spring will go into this .030 step cut, it will most likely be ok being the pocket will center the spring along with the retainer. The smaller 1.245 spring has a pretty big hole and these guys know that your supposed to run a spring locator. Never run a spring that will move side to side under any condition. It should have a .060 step to set inside of when sitting on the head. The same goes for the retainer, it should fit snug. The bottom of even stock gm ford etc heads have a perfect seat and base for the spring to rest in and not move around. Bad enough to have the springs dancing around eating your heads up let alone the material in your engine. WE ALWAYS USE A LOCATOR. Yes those 1.240 srpings @ 110 on the seat will work well up to .550 lift with a solid cam and 5500 rpm with that valve train weight. Run a roller rocker or roller tip, this will help with heat.

[malihoochie]

The valve guides will keep the springs located properly.

Don

Want-a-be is correct.
Mongo the spring pocket on those heads is larger to accomodate many different springs, the cam you mentioned would use the 1.250"spring. ;)