valve springs
#1
Banned
Thread Starter
valve springs
Hey guys, Quick question, my head is at the machine shop getting rebuilt, I'm being told that I need new valve springs because the old ones are weak at 105lbs, I've done valve seals and have the tool to remove the springs, Can I replace the valve springs myself or would the machine shop need them to finish doing a rebuild? I'm just trying to save myself some $$ as I'm being told its $230 to have them do it, and I can get the springs for $146 and do it myself.
#2
Rennlist Member
Ideally you want to measure the force at the "installed height" of the springs, and put shims under them as necessary.
But, chances are, if you just put the springs in, you'll be fine.
But, chances are, if you just put the springs in, you'll be fine.
#3
Rennlist Member
105 to 110lbs is about what I have measured on most used OEM springs. On a stockish motor they are probably fine. I think the springs run fairly close to coil bind and loose some strength early and then level out at about 105-110lbs. Was 105 the minimum? At what installed height? I would be interested in others comments on this.
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#9
Hey guys, Quick question, my head is at the machine shop getting rebuilt, I'm being told that I need new valve springs because the old ones are weak at 105lbs, I've done valve seals and have the tool to remove the springs, Can I replace the valve springs myself or would the machine shop need them to finish
doing a rebuild? I'm just trying to save myself some $$ as I'm being told its $230 to have them do it, and I can get the springs for $146 and do it myself.
doing a rebuild? I'm just trying to save myself some $$ as I'm being told its $230 to have them do it, and I can get the springs for $146 and do it myself.
The 951 exhaust Si-Valves are significantly lighter (just 94 gramms) than the stock exh. valves and cheaper than new springs.
left: my race prepped stainless steel exhaust Si-Valve, right: non race prepped exh. Si-Valve, 94 gramm (3.3158oz)
#10
Instead of new springs, another option could be lightweight SS Si-Valves. Especially the exhaust valves. As we know over-revving hurts the mainly the exhaust valves.
The 951 exhaust Si-Valves are significantly lighter (just 94 gramms) than the stock exh. valves and cheaper than new springs.
The 951 exhaust Si-Valves are significantly lighter (just 94 gramms) than the stock exh. valves and cheaper than new springs.
Can you get them also in other place (seem to be not available) and what are the quality of those valves?
#11
Do you mean these ones? http://fcrcmachine.com/i-19290330-ne...l-e-t3087.html
Can you get them also in other place (seem to be not available) and what are the quality of those valves?
Can you get them also in other place (seem to be not available) and what are the quality of those valves?
No problems so far.
#12
I beleive Shawn is using the SI valves as well as he was the person who told me about them.
#13
Rennlist Member
I have built a few heads using SI Intake Valves. No issues so far. They are a bit on the heavy side but quality is good and the price is excellent. I like to use stock exhaust valves however because they are sodium filled.
#14
What are the advantages of the sodium fill? Better heat resistance/transfer?
#15
Rennlist Member
Heat transfer. Keeping the exhaust valve cool is very important on a turbo car, especially if you track the car.