Redtop SR20DET timing and head gasket question - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

ST3ALTHPSYCH0 · 05-28-2012, 06:01 PM

First, the timing issue (which I think lead to the HG). I was having bogging and what not, so I decided to check the timing. Timing light showed it to be about 2-2.5" to the right of the 20* BTdC mark. My bogging ended up being due to 1) the compressor inlet gasket leaking and 2) a 20 year old 75 lph fuel pump (I got the car already swapped.... I stupidly assumed that it was done correctly). However, through the process it set the timing so that it was 15* BTDC according to the timing marks. It bogged, backfired and had horrid throttle response. My question is: can the crankshaft pulley be misaligned on the crankshaft? Last CSP I pulled was on a Camaro, and it was keyed.

Now the HG. Replaced the compressor inlet gasket, dropped in a Walbro 255, put the timing back where it was (the clean spot on the CAS looked like that's where it's been for its whole life), and she ran like a scalded dog this morning. I did some spirited highway and surface road driving (redline in 2nd and 3rd, brisk acceleration, etc) and came home and parked it. While I was sitting in the car, I started hearing hissing (though I might have picked up a nail or something), but when I got out, I smelled hot antifreeze. I popped the hood hoping to see the radiator cap venting, but instead (after some serious searching) I found the steam escaping between the block and head between the #1 and 2 cylinder.

With that said, I want to make sure I have a few things straight:
First, if a straight edge shows no gaps, I can get away without having the surfaces resurfaced, yes?
Second, my plan (broke as I am) is a cosworth MLM 1.1 mm gasket with ARP head studs; I have found them on EBAY new at $130 for the studs and about $175 shipped for the gasket. Is there either a cheaper place to get them or a better value? I'm running the stock T25 @ 11 or 12 PSI on an otherwise stock engine, I'm sure that matters.
Third, Does copper spray == Indian head Liquid copper gasket shelac? I only ask because I have a bottle of Indian Head.
Forth, I can't tell from the tear downs I've seen, Can I get by with just pulling the manifolds, or will I have to completely tear them down (I.E. pull the whole turbo and the fuel rail)?
Fifth, I've read in some of the other HG threads that you use the FSM for the tightening pattern, but not the torque when using an aftermarket HG, true?
Finally, is there a breakin period for head gaskets?

Sorry for what are surely some stupid questions, but I'm only a shadetree mechanic due to the fact that I can't afford to pay someone else. I've not done a HG on ANYTHING in this first 30 years of my life, so I'm a little leery.

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05-28-2012, 06:01 PM	#1
ST3ALTHPSYCH0 Leaky Injector Join Date: May 2012 Location: Chattanooga, TN Age: 42 Posts: 55 Trader Rating: (0) Feedback Score: 0 reviews	Redtop SR20DET timing and head gasket question First, the timing issue (which I think lead to the HG). I was having bogging and what not, so I decided to check the timing. Timing light showed it to be about 2-2.5" to the right of the 20* BTdC mark. My bogging ended up being due to 1) the compressor inlet gasket leaking and 2) a 20 year old 75 lph fuel pump (I got the car already swapped.... I stupidly assumed that it was done correctly). However, through the process it set the timing so that it was 15* BTDC according to the timing marks. It bogged, backfired and had horrid throttle response. My question is: can the crankshaft pulley be misaligned on the crankshaft? Last CSP I pulled was on a Camaro, and it was keyed. Now the HG. Replaced the compressor inlet gasket, dropped in a Walbro 255, put the timing back where it was (the clean spot on the CAS looked like that's where it's been for its whole life), and she ran like a scalded dog this morning. I did some spirited highway and surface road driving (redline in 2nd and 3rd, brisk acceleration, etc) and came home and parked it. While I was sitting in the car, I started hearing hissing (though I might have picked up a nail or something), but when I got out, I smelled hot antifreeze. I popped the hood hoping to see the radiator cap venting, but instead (after some serious searching) I found the steam escaping between the block and head between the #1 and 2 cylinder. With that said, I want to make sure I have a few things straight: First, if a straight edge shows no gaps, I can get away without having the surfaces resurfaced, yes? Second, my plan (broke as I am) is a cosworth MLM 1.1 mm gasket with ARP head studs; I have found them on EBAY new at $130 for the studs and about $175 shipped for the gasket. Is there either a cheaper place to get them or a better value? I'm running the stock T25 @ 11 or 12 PSI on an otherwise stock engine, I'm sure that matters. Third, Does copper spray == Indian head Liquid copper gasket shelac? I only ask because I have a bottle of Indian Head. Forth, I can't tell from the tear downs I've seen, Can I get by with just pulling the manifolds, or will I have to completely tear them down (I.E. pull the whole turbo and the fuel rail)? Fifth, I've read in some of the other HG threads that you use the FSM for the tightening pattern, but not the torque when using an aftermarket HG, true? Finally, is there a breakin period for head gaskets? Sorry for what are surely some stupid questions, but I'm only a shadetree mechanic due to the fact that I can't afford to pay someone else. I've not done a HG on ANYTHING in this first 30 years of my life, so I'm a little leery.