I don't know if you guys want to rehash this, I did a search and came up with a discussion about this issue, but it seemed more slanted towards a dual spring offering your engine extra protection if a spring breaks rather than any peformance hit you might take using a dual .650 spring with that small of a cam.

When I bought my TR224/112 cam I ordered Comp 918 springs because I felt they were the perfect spring for that cam, and I still do. A year later I ordered a set of PP 243 ported heads (which I'm in the process of installing now) and it came with Patriot Dual .650 springs. So I'm actually going with those springs with my TR224 cam and stock rockers.

I was wondering what the difference will be running these dual springs as opposed to the 918s? I understand that using a spring designed for bigger cams is not really a good thing despite any extra protection it might offer. Will I be unhappy with those PP dual .650 springs and my small TR224 cam? And what happens (goes wrong) when you use a heavy duty spring like that with a small cam? Thanks.

 

Slightly more resistance on the valvetrain which is going to result in slightly more parasitic loss to move the stiffer spring. I doubt you would see more of a 3-5hp difference on the dyno. I wouldn't run anything but a dual spring seeing as if one of those springs break on a 918, there goes a valve, and there goes an engine. At least with the duals you have a back up spring to hold the valve up.

 

I used those springs with a 224 in an old setup and it was fine

 

I heard that even with a dual spring breaking at higher rpms you're still going to have a collision between a valve and a piston. Is that true? If not, the extra safety would definitely be worth a few hp loss. Thanks.

HAMRHEAD, thanks for posting your experience with that combo. You don't know how glad I am to hear it. Thanks.

 

Use them for the extra safety. It's not perfect insurance, but there are people on this board who have been saved....

 

<It's not perfect insurance, but there are people on this board who have been saved....>

That's definitely a good thing. Thanks.

 

I ran 918's when I put in my TR224 cam. I felt and still do, that they are the right springs for that cam. When I bought my AFR 205's, the only ones available at the time had the upgraded dual springs. Since I got them for the same price as the single spring and got them right away, I went with them. If I had a choice I would go with the single spring.

Dual's may provide extra protection if a spring brakes, but........They do produce extra strain on the valvetrane, mainly the valve. I have seen a valve stem pull right off on a set of AFR 205's with dual springs. Weather that had anything to do with the dual springs, or just shitty valves (we know AFR used them at one point) Who knows.

I would not worry over it though.

 

So Dave, what was your experience running the duals with your AFRs? Any problems, strange sounds, low dyno numbers, anything? Thanks.

 

Car made 432rwhp/403rwtq. I wouldn't say low #'s. I made 38Xrwhp/370rwtq cam only. Gained ~50rwhp & 33rwtq with the AFR's. I do hate the dual spring sound you get though.

I'm totally happy with the heads.

 

I don't think that a stiffer spring will cause more parasitic loss over a single. For every one spring being pushed down there is one pushing right back up canceling each other out.

 

I run a TR224 112 with Patriot Gold Duals

My engine is quiet thank god, took awhile of figuring out how to tighten the rockers properly but I got it now. I have a Monte with a 5.3 and the spring sound is similar.

 

SladeX, what did you have to do beyond the usual procedure for tightening the rockers? Thanks.

Dave, those are fantastic numbers, congrats! I would have gotten the AFRs if I had an extra thousand laying around.

Thanks for the feedback mchdg86.

 

My friend's ws6 had a set of MTI heads that came Manley springs on a TR224 on a 114. The springs wore after 2 years of racing and street driving and they needed replacing. Manley stop making the spring and we couldn't find a manley replacement so we called thunder racing and they recommended the patriot gold dual spings. We installed the awhile back and no issues or complaints so far.

 

silverbullet, this kind of feedback is really giving me peace-of-mind. You don't know how much I worried about using dual springs with the TR224.

Thanks for taking the time to respond.

 

 

Does that mean you don't agree?

 

I ran the duals with my 224 without any problem. I then upgraded to a bigger cam and heads. Had 2 of the dual springs break on me (not sure of the brand) and was lucky enough to have no valve damage. Went with the Patriot extremes. Have had zero problems so far. You also never know when you might want to upgrade the Cam, and you will want the extra lift that the duals provide. Good luck with your new set-up.

 

Great info 99LSS1, I'm feeling really good about these dual springs now. I didn't think about maybe upgrading the cam in the future. That's a good point, and another advantage to the duals.

Thanks for the well wishes! Same to you!

 

If you ever change cam, I would replace the springs too. Some people believe the springs develope a "Memory", and have a tendency to brake or brake valves after changing the cam with the old springs.

Just something I heard. Not sure of the validity of it.

 

I'm running the 224 with the dual springs and it's been just fine for me for 15k miles now...