327_TPI_77_Maro

iTrader: (8)

Hi guys, I just installed a pair of World Products heads that I got back from the machine shop. I installed 1.25" valve springs, because I assumed these heads were just set up for that size. The heads are the 01115's but I don't know if they are 01115-1's (1.25" springs from the factory) or 01115-2's (1.46 double springs).

However, I did notice that the seat area around each valve springs was cut deep to 1.25, and also had a much shallower step machined around the 1.25 pocket at the 1.46 size.

Does this mean the heads are machined for the 1.46 double spring, did even the 01115-1 heads have that shallower 1.46 step machined around the 1.25 pocket and it would need to be machined further in to use a 1.46 spring?

If these heads are indeed machined for the 1.46 double spring, and I used just the 1.25 single spring w/ damper (with enough seat/open pressure of course, I matched the springs to the cam card), will I have done any harm?

F-BIRD'88

As far as i know all recent Sportsman II heads are machined for both spring sizes. The little step in the spring seat just keeps the small 1.26" spring located so it does not dance around. 1.26" equipped versions use a standard length valve. 1.46" spring assembled version get a +.100 valve. As long as you check and set your spring installed height and coil bind clearance you're good to go. but.....

A aggressive hyd roller cam is much harder to control at high rpm. The lifters are heavy. A larger 1.46" dual spring with damper is often nessessary.
Which 1.26" springs did you use? Some are not up to the task of working with a aggressive hyd roller cam and will limit the rpm capability. (especially with heavy retro fit lifters.)
If you get carried away with rpm and get into valve float 'cause the springs are not up to it, you risk smacking the pistons with the valves.
Now how much did ya save by not using the right springs?
Aggressive aftermarket "extreme" hyd roller setups require premium valve springs. Beehive springs work very well.

327_TPI_77_Maro

iTrader: (8)

The valve springs are 1.25 135 closed, 340 open, at my cam's lift. I checked them on a spring checker, and I have set installed height appropriately. I have 0.060-0.080" before coil bind at my installed height. The cam is very mild, 0.503"/0.510", 224/230 @0.05 duration (it's an XM274 Extreme Marine cam, but I am using it on the street because I like the specs). This spring matched up w/ Comp's recommended double spring specs fine. The specs were specifically for this cam with the heavy retro fit lifters. Thanks for the info. I had to replace a couple valves when I had the heads rebuilt, and I ordered standard length valves, and they were the same height as the rest. So this tells me that these heads came with 1.25s originally.

This is not an extreme roller setup by any means, its a little street roller for the 327, which needs a lot less cam than a 350 to be able wind up

Thanks for the info, very helpful on how this head had the +.100 valves w/ the bigger spring. It sounds like I should be okay. I will only be turning around 6200 max with this setup.

Damon

Your observations are correct- the Sportsman IIs do have a lower step for stock-diameter springs. I believe they do this as a spring locating device for the smaller diameter springs. As long as you are happy with your springs specs matching your chosen cam and have adequate clearance to coil bind you should be fine.

Just work up the RPM range easy your first few times out. Hydraulic rollers are notorious for being difficult to control the valve train as the tach swings past 6000. The boards are littered with posts from guys with mild hydraulic rollers that don't seem to be able to get the thing to RPM the way they expect it to, even with the proper springs installed and checked for height. Even mild rollers typically have much more aggressive ramps than flat tappet cams.