I have a 555" BBC in a pipe rack that goes 7.40s, best of 7.32/182. I spin it 76/7700 in the lights and the gross lift is .858/.778. I'm running Manley Nextek 221424 (blue stripe) springs, and they are installed as per their directions, they are .050" from coil bind when fully open (and taking into account lash of .028/.030 hot).
I'd like to get better life out of my springs. Some of the intakes I've had to change after 35 runs. They go in at 260-270 on the seat and I change them at 220 as I broke an inner one last year that had 77 runs on it (before I was checking them a lot) and the rest pulled 220. Exhausts seem to last just fine since the valve is lighter.
I called Manley yesterday and they recommended trying the polished springs, so maybe I'll pick up a set and put them on the intakes. But I wanted to get some input from here - is there another spring I should try that would give me longer life?
Posts: 743 | Location: Upstate NY | Registered: July 02, 2013
I only run polished springs on my engine. My slow car (7200 rpm SBC) gets standard springs. I always use PAC, but there are really only two companies making springs. Not sure if they use the same materials and process though for all the different companies they produce them for.
Posts: 1444 | Location: South River, NJ | Registered: June 19, 2007
Originally posted by 183N: I have a 555" BBC in a pipe rack that goes 7.40s, best of 7.32/182. I spin it 76/7700 in the lights and the gross lift is .858/.778. I'm running Manley Nextek 221424 (blue stripe) springs, and they are installed as per their directions, they are .050" from coil bind when fully open (and taking into account lash of .028/.030 hot).
I'd like to get better life out of my springs. Some of the intakes I've had to change after 35 runs. They go in at 260-270 on the seat and I change them at 220 as I broke an inner one last year that had 77 runs on it (before I was checking them a lot) and the rest pulled 220. Exhausts seem to last just fine since the valve is lighter.
I called Manley yesterday and they recommended trying the polished springs, so maybe I'll pick up a set and put them on the intakes. But I wanted to get some input from here - is there another spring I should try that would give me longer life?
Couple of things...
Polish springs aren't going to fix this.
I have seen bad springs/batches from all these guys in the past so sometimes its pot luck.
I assume you have a set of conventional heads with a 2.30 - 2.35 steel intake valve??? What's your available/tallest installed height on your heads? I'd like to see closed pressure around 300. Also don't over due the close to coil bind deal! More WILL NOT HURT YOUR SPRING LIFE & MAY HELP! I'd get a set of PAC 1228 and install them around 2.060 -2.070" which will get you over 300 on the seat.
You should also check you actual valve lift at the valve! You may be surprised at what you see!
Al, thanks for your reply. I've had bad springs too - had 2 install 20# low, figured I'd give them a couple runs and see what they did. They lost another 25# and were down to 220 so I threw them out.
To answer your questions, yes it's a conventional head, 2.300 steel valve. The intakes are currently installed at 1.980 which is the tallest I can go right now. No shim, just the spring cup. I'd also like to get the seat pressure around 300# as that's what the exhausts are.
ThanksThis message has been edited. Last edited by: 183N,
Posts: 743 | Location: Upstate NY | Registered: July 02, 2013
I run a small block and have had good results with PAC springs. With that said I believe you have some issue causing the springs to fail long before they should. Your cam and RPM is not that much to be going through springs like that. Spring bind, float or some kind of other issue causing the problem.
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Posts: 4352 | Location: United States of Texas | Registered: April 02, 2011
This conversation should include how much oil you're sending to the top. Is your .050 based on calculated or mocked up with a 424? You'll pick up some with deflection. I'll argue that oil is just as crucial to spring life as proper installation. PAC has some better springs in the larger wire but a 424 has an awesome CB height due to its smaller wire. BW
Posts: 195 | Location: Rock><Hard Place | Registered: February 20, 2010
On a valve train of that weight, you should be seriously consider removing them when they get around 295-300. If you can read between those lines, you have the wrong springs in that engine.
A typical "average" cost bracket racers spring for your engine, and it's valve train weight, should be in around 320-330 on the intake, and if you'd like, your exhaust can be in at around 280 to 290.
Originally posted by 183N: Al, thanks for your reply. I've had bad springs too - had 2 install 20# low, figured I'd give them a couple runs and see what they did. They lost another 25# and were down to 220 so I threw them out.
To answer your questions, yes it's a conventional head, 2.300 steel valve. The intakes are currently installed at 1.980 which is the tallest I can go right now. No shim, just the spring cup. I'd also like to get the seat pressure around 300# as that's what the exhausts are.
Thanks
Not 100% sure but I believe you can get cups that are .030 thick rather than .060 and with plus .050 keepers you could make those 1228 springs work.
I started using a break in process. I completely compress and then back to zero load each spring in a vice 3 times. I then install. I start the engine, at idle (1100 rpm), bring temp to 150. Let cool overnight twice. 3rd start I let temp rise to 180 and let cool overnight. Check spring pressure, race approximately 100 passes, recheck spring pressure.
Posts: 28 | Location: elsewhere | Registered: December 11, 2008
First off do you warm the motor up to like 160 and then let it steep the heat through out for about 15-20 minutes? I've gotten 300 runs out of the nextec 250 seated at 2 inch springs with about 235-240 at 2 inch after the 300 runs. Haven't broke one yet inner or outer.
Posts: 30 | Location: Delaware | Registered: March 14, 2011
Bry-war that’s calculated, never measured it, but do have 7/16” pushrods. As far as oil, I run a moroso hv billet pump, no restrictors.
Chris I warm it up every morning to at least 185 water and 150 oil then let it soak. I did get almost 200 runs out of my first set of these, never checked them then and maybe got lucky. But I also had a tighter converter then and was turning it 200rpm less so that could be why. Regardless, I’d like to get mine to live like yours. Are you spinning a similar rpm with similar cam?
Al, I’ll look into the skinnier cups - thanks. Building a new engine this winter so this engine will be the spare for either my or my wife’s car. Maybe we’ll go with a slightly longer valve with the new piece that’ll give us more room. The new one is basically going to be a copy of what I have now.
Posts: 743 | Location: Upstate NY | Registered: July 02, 2013
I run the Nextek 424 spring. I just replaced them at 566 runs. I replaced them because I broke 2 outer springs. I felt this was a little premature but in general I was happy with the life of the spring. What I did not like was that on the new set the pressure varied significantly on a few springs even though they were installed at the same height. In one case it varied by 30 lbs more than the others so I do question their quality control. Next time I will try a different brand, probably pac.
Question regarding rtpaske's issue with his new springs.
If there are a few springs that are coming up low, what is the preferred method to deal with it? Call manufacturer and get another set, or have them send you some and you send the weak springs back? Or, if you have the room, shim them to get the proper pressure provided you did not get a spring that was close to coil bind to start with?
About to change my springs and this time I am checking ALL of them on a bench mounted tester before I put them on the heads so I know exactly where they are started. I found some that should have been installed at 260, but down to 200, others are still at 260, two were at 280. I measured the installed height on each valve assembly before putting the springs on, so I know that was correct. Which leads me to believe either some were low to start with or they are simply worn out.
This time around I will know where they ALL are to start with.
Posts: 1444 | Location: South River, NJ | Registered: June 19, 2007
May seem silly but is the OP using a retainer to check pressure? Alot of guys get this process wrong by not using a method to get the pounds that you lost by instrument travel. I like to use the back side of a pair of calipers locked down at inst height and stick the point in the gap at the tail of the spring. Setting your tester travel without pressure will net a surplus of height and low pressure. Ownership of a rimac will require the use of a clibration spring if it doesn't live in a vault (with bubble wrap of course).
Posts: 195 | Location: Rock><Hard Place | Registered: February 20, 2010
