Bent valves
#1
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Bent valves
So the other day I changed my water pump, belts, etc. Well I screwed up and didn't tighten the intake cam gear. The gear slipped today, bending all 8 intake valves. Now, I am not trying to be cheap, I am just curious. I was running Supertech valves on both intake and exhaust, but I have a nice set of OE intake valves. Can I use those with my boostz?
#4
Sorry. I see many here make a reliable 250whp on the street with stock motors. It depends on your application. I don't know if all the track guys upgrade em (Some do, obviously), but for street use at 250whp, I personally don't see any reason not to just throw the OEM valves in. Will you be tracking your boostz?
#7
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Sorry. I see many here make a reliable 250whp on the street with stock motors. It depends on your application. I don't know if all the track guys upgrade em (Some do, obviously), but for street use at 250whp, I personally don't see any reason not to just throw the OEM valves in. Will you be tracking your boostz?
If you get some time check out the build thread, there are some videos in the last couple of pages.
https://www.miataturbo.net/build-thr...o-build-67816/
When the cam gear slipped it jumped time and they hit the pistons.
My biggest concern is when this car starts seeing more and more track time at the same level of power if its going to cause an issue down the road.
I guess if it does I will address it then. So for now, I will order a new headgasket, throw these in it and get back to it.
#9
If it was the exhaust side, then without a doubt I would be buying and sticking the stainless steel ones back in it. I'm just not sure if the intakes are seeing that much abuse/heat to put the stainless steel ones back in.
I guess if it does I will address it then. So for now, I will order a new headgasket, throw these in it and get back to it.
I guess if it does I will address it then. So for now, I will order a new headgasket, throw these in it and get back to it.
Remember, Soviet is making more than 360 with stock valves and NASTY timing table. If I were to upgrade only one side it would be the exhaust on a turbo car and intake on NA.
I would quickly hand lap them in though, and by hand I mean with a cordless drill.
#10
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So it's decked enough to an interference engine? Or is that the forged piston's fault?
The entire head has to obviously be rebuilt, or at least that side. I'd just do the supertechs while I'm at it. No point in half assing it now. Although it sounds like we're questioning the benefit of "upgraded" valves.
The entire head has to obviously be rebuilt, or at least that side. I'd just do the supertechs while I'm at it. No point in half assing it now. Although it sounds like we're questioning the benefit of "upgraded" valves.
#11
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So it's decked enough to an interference engine? Or is that the forged piston's fault?
The entire head has to obviously be rebuilt, or at least that side. I'd just do the supertechs while I'm at it. No point in half assing it now. Although it sounds like we're questioning the benefit of "upgraded" valves.
The entire head has to obviously be rebuilt, or at least that side. I'd just do the supertechs while I'm at it. No point in half assing it now. Although it sounds like we're questioning the benefit of "upgraded" valves.
#12
If you are putting in the stock valves, at least get the valves resurfaced first, to make sure they are round. When lapping, (not my recommended procedure) make sure the lap is not too close to the outside of the valve seat. (or too close to the center, I doubt that) With all the other work done, I am wondering if the valves were perhaps +1mm? If so the stockers wont work.
#14
What do you mean by this? I don't understand when you infer that you don't recommend lapping the valves? I WOULD NEVER install a head that didn't have the valves lapped in. Well, maybe on an engine I don't care about. But not a FI engine and certainly not this one! Sure, a full valve grind and lap would be better......but I don't see a problem if the seats are in good shape and you get a good seal when lapped then you will be fine in my opinion.
#16
If anything, stock valves will be stronger at the point where the stem meets the valve.
The reason most people get valves in the first place is because performance valves are undercut for added flow. The undercutting process makes valves more fragile to collisions. It is a trade off between flow and strength.
The reason most people get valves in the first place is because performance valves are undercut for added flow. The undercutting process makes valves more fragile to collisions. It is a trade off between flow and strength.
#17
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If anything, stock valves will be stronger at the point where the stem meets the valve.
The reason most people get valves in the first place is because performance valves are undercut for added flow. The undercutting process makes valves more fragile to collisions. It is a trade off between flow and strength.
The reason most people get valves in the first place is because performance valves are undercut for added flow. The undercutting process makes valves more fragile to collisions. It is a trade off between flow and strength.
Here is a sample lol
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