Pat's Ebay Turbo Compound Boost Build
#1101
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I will PM it to you, but I don't know they that actually fit so I'm not gonna post it here and then someone buy parts that don't fit. If they work I'll update the thread of course.
EDIT: They fit, ARP-200-8747
EDIT: They fit, ARP-200-8747
Last edited by patsmx5; 03-09-2017 at 11:11 PM.
#1104
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The supertech's failed me twice. All of them, intake and exhaust alike. The intake valve guides are not shot like the exhaust, but the supertech valve stem seals pour oil as well. I'm not running them again. I dropped off what I think were FEL-PRO seals at the machine shop with the head. Not sure if they will use them, or use some other brand. Actually I will be sure and tell them not to run supertech seals again but I don't think they will since I had to order the replacement supertech valves that were bent.
#1108
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Maybe I missed it, but was there a knock logged when the bent valves occurred?
Only ask because I have heard old stories of valves bending from knock before. Just hearsay, but it is not necessarily an unusual story. The way you say, there is not a mark on the pistons, sounds familiar.
Only ask because I have heard old stories of valves bending from knock before. Just hearsay, but it is not necessarily an unusual story. The way you say, there is not a mark on the pistons, sounds familiar.
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I don't know when the bent valves occurred. It could have been years ago for all I know. When the car had 10.5:1 pistons (previous bottom end with this cylinder head about 2 years ago) it had A LOT more power. When I put this head on my 9.0:1 bottom end it felt weaker everywhere by what I think was 15-20%, but I assumed it was the lower compression from the pistons. It was down on power enough that I was pretty sad and regretting dropping the compression. Would be funny if it WAS from lower compression, just from pistons + leaky bent valves... I noticed exhaust valve interference on reassembly, so maybe I bent them then though I was really careful it could have happened. Or it could have happened at high RPMs or high boost. I've pushed the engine harder than ever with this motor combination. Best guess for a component failure would be the supertech heavy double valve springs are not stiff enough, but there's nobody running the boost/RPM I run to compare to. It was asked if I measured turbine inlet pressure on m.net, they guy may be asking/suggesting I blew the exhaust valves open and floated them from that. I've run 40 PSI boost so turbine pressure was probably 50-60 or who knows what.
#1110
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Valves arrived at machine shop. I asked them about the valves could have bent, asked if it could be the loose guides. He said piston probably bent them. We talked about what could cause that, he said possibly a weak valve spring. He's going to check them.
#1112
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I don't have the head back to check anything right now. Like I said I found it was interference when I originally put this head on 2 years ago, so I know with incorrect cam timing it's possible.
#1117
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That is pretty funny! The stock auto was disappointing, I thought I could get more out of it. But to be honest, I don't object to most sport-tuned autos these days. I have a 2014 car with a 7 speed auto and it's great.
I broke an axle at the dragstrip, but I have not broken the diff*
*yet!
#1118
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Just fired it up. Starts better, knew the compression was higher as I could literally hear it hitting over harder on the starter. Let it idle a few minutes and then check compression. So semi hot numbers? I'll drive it and retest in a couple days. Test showed
1: 152psi
2: 151psi
3: 148psi
4: 140psi
So way better than before, but not perfect. I expect them to come up a bit with a hot motor but cylinder 4 is a bit lower than the rest. Gonna boost the nuts off of it anyway! But it looks like a bottom end refresh will be needed in a year or two.
More later, but it's alive! Cooling system has an air bubble or something so I gotta burp it and do a few little things, then I'll drive it.
1: 152psi
2: 151psi
3: 148psi
4: 140psi
So way better than before, but not perfect. I expect them to come up a bit with a hot motor but cylinder 4 is a bit lower than the rest. Gonna boost the nuts off of it anyway! But it looks like a bottom end refresh will be needed in a year or two.
More later, but it's alive! Cooling system has an air bubble or something so I gotta burp it and do a few little things, then I'll drive it.
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It can tell you if you have damaged rings or leaky valves on a cylinder, for instance. Generally speaking, higher CR pistons will yield a higher number. More cam overlap generally gives lower numbers, etc. Lots of variables. An engine with big cams may make lots of power but read lower than it would with stock cams.