that one guy Posted October 29, 2012 Report Share Posted October 29, 2012 So I'm doing a motor swap, and I have a little issue. My old motor seized, and I'm re-using the head off it. The head is an N47, came off an N42 block, gonig back on an N42 block. The problem is that the motor didn't seize at TDC (wouldn't that be nice) and I have no idea how to get it back to TDC. Any help? Quote Link to comment
Ranman72 Posted October 29, 2012 Report Share Posted October 29, 2012 number one piston at the top and marker on the front pulley pointing at 0 Quote Link to comment
Dat Lurka Posted October 29, 2012 Report Share Posted October 29, 2012 Whats it matter? Take the head off. Put "new" engine at halfway past tdc #1 so that the pistons are in line. That was you can turn the cam to "tdc" ( cam lobe positions 11 and 2?, notch lined up with plate)without hitting the pistons with the valves. I had to do it on my engine because I installed the head at tdc #2. Yes I was drunk. Had to turn the cam through cause it was upside down. 1 Quote Link to comment
banzai510(hainz) Posted October 29, 2012 Report Share Posted October 29, 2012 what I do if head is already off is but block so poistons are half way in the middle Bolt the head on there using the 2 center head bolts. Rotate the cam so its at TDC. Youll know watch the vid. Or if sprocket is okk the cam dowl pin will be close to the 12o clock position. then take head off rotate crank till front piston is right at TOP. You can loosely put the front cover back on the ck for TDC marks or mak a ink pen mark for true TDC. Hopefullyou all the big blts were loosen before you took everything apart as its hard to remove the crank bolt of head is already off 1 Quote Link to comment
datzenmike Posted October 29, 2012 Report Share Posted October 29, 2012 Pull siezed motor and remove head. Place new motor in car. Turn new motor to TDC on #1 Lock chain so tensioner won't fall out Remove head. Put old head on new motor. Quote Link to comment
EricJB Posted October 29, 2012 Report Share Posted October 29, 2012 Just a thought. If the old motor siezed from oil starvation, the head is probably toast as well. At least the cam/ towers. Quote Link to comment
that one guy Posted October 29, 2012 Author Report Share Posted October 29, 2012 The head is fine, I had it checked. I have no idea what Ranman and Dat Lurka are talking about. This is the first time I've ever had a motor apart. The video seems helpful, I'll watch it when i"m back from work. Quote Link to comment
Dat Lurka Posted October 30, 2012 Report Share Posted October 30, 2012 What am I talking about?? What are YOU talking about? "My old motor seized, and I'm re-using the head off it. The head is an N47, came off an N42 block, gonig back on an N42 block. The problem is that the motor didn't seize at TDC (wouldn't that be nice) and I have no idea how to get it back to TDC. Any help?" You're saying here that you want to turn the frozen motor to TDC. What I figure you meant to say is you need to turn the HEAD to TDC before installing on "new" engine. I was explaining how to do that. Read what hainz said under his vid, same thing. Semi install the head with engine at halfway tdc, as in pistons in the middle, so you can turn the camshaft to TDC (cams at 11 and 2, notch on gear aligned with plate on cam tower) without hitting the pistons. Then return engine to TDC so you can install the timing kit. Quote Link to comment
Dat Lurka Posted October 30, 2012 Report Share Posted October 30, 2012 It's a 4 cylinder but same concept. I didn't realize you were talking about a Z engine. Here these may help. Stupid pictureless explanations. Basically you want the pistons to look like this when you put the head on to turn the cam. If it is a TDC, you will probably hit the pistons with valves trying to turn it through. Turn the cam to TDC position while the pistons are down. Heres some examples. Look at the middle of pic. See the little triangular notch aligned with the dash on the plate? Cam lobes Then remove the head and turn engine to TDC. #1 piston at the top. Not sure what a Z crank looks like but surely theres a notch and a 0 somewhere. Now you can install your TDC head to TDC engine. Quote Link to comment
I'm BLUE Posted October 30, 2012 Report Share Posted October 30, 2012 Go here ---> http://www.xenons30.com/reference.html Down-load and read the factory service manual (FSM). It will tell you everything you need to know and more. Much faster than we should be able to in interwebs slow time .. (exception is hainz's video) it really does not matter where you engine is/was/were ,,, you will be lining up TDC ... at the same place ... like every other engine will be. Front crank bolt is a 27mm Now is a good time to check timing chain slack/replacement or advancing the sprocket 1 position on the new engine. If new engine is still out .. replace the rear-main seal. You'll love your-self for doing so later on. There should be 2 hollow head alignment dowels sitting in the new block. If not , rob the old engine and swap. You'll see where they are located by looking at the casting in the head/block. Make absolute sure to use a timing chain wedge if you plan to just swap heads period.. homemade or store bought. Does not matter which. To keep your timing chain tensioner from opting out. Quote Link to comment
Mirrorimg Posted October 30, 2012 Report Share Posted October 30, 2012 What am I talking about?? What are YOU talking about? "My old motor seized, and I'm re-using the head off it. The head is an N47, came off an N42 block, gonig back on an N42 block. The problem is that the motor didn't seize at TDC (wouldn't that be nice) and I have no idea how to get it back to TDC. Any help?" You're saying here that you want to turn the frozen motor to TDC. What I figure you meant to say is you need to turn the HEAD to TDC before installing on "new" engine. I was explaining how to do that. Read what hainz said under his vid, same thing. Semi install the head with engine at halfway tdc, as in pistons in the middle, so you can turn the camshaft to TDC (cams at 11 and 2, notch on gear aligned with plate on cam tower) without hitting the pistons. Then return engine to TDC so you can install the timing kit. This is right. No matter what position the seized motor is in, once you remove the head you can set the cams in any position you want. Put your new block at TDC, put the cams at TDC, then put the head onto the block. Simple as that. Quote Link to comment
Dat Lurka Posted October 30, 2012 Report Share Posted October 30, 2012 Make absolute sure to use a timing chain wedge if you plan to just swap heads period.. homemade or store bought. Does not matter which. To keep your timing chain tensioner from opting out. Quote Link to comment
that one guy Posted October 30, 2012 Author Report Share Posted October 30, 2012 What am I talking about?? What are YOU talking about? "My old motor seized, and I'm re-using the head off it. The head is an N47, came off an N42 block, gonig back on an N42 block. The problem is that the motor didn't seize at TDC (wouldn't that be nice) and I have no idea how to get it back to TDC. Any help?" You're saying here that you want to turn the frozen motor to TDC. What I figure you meant to say is you need to turn the HEAD to TDC before installing on "new" engine. I was explaining how to do that. Read what hainz said under his vid, same thing. Semi install the head with engine at halfway tdc, as in pistons in the middle, so you can turn the camshaft to TDC (cams at 11 and 2, notch on gear aligned with plate on cam tower) without hitting the pistons. Then return engine to TDC so you can install the timing kit. This is exactly what I meant, thought I was clear, but internet speak is confusing. I don't know about you guys, but my sprocket has three alignment holes, don't know which one to use, and I sorta guessed the marking on the cam was to set it to TDC. I already replaced the rear main seal, and the aligning sleeves are there. The motor was completely stripped down and everythign gone through/replaced as needed. The chain tensioner I'm not worried about as I have the timing cover off. Thanks for all the help guys, as I have the FSM and I couldn't find this anywhere. I'll throw some pics up in this and my build thread when it's all said and done. :thumbup: Quote Link to comment
Dat Lurka Posted October 30, 2012 Report Share Posted October 30, 2012 Woohoo! Did you get the head surfaced? Valve job? Better now than later. Quote Link to comment
that one guy Posted October 30, 2012 Author Report Share Posted October 30, 2012 No, and I would tend to agree, but I have a second N47 head, which will be surfaced, get a valve job, aggressive port and polish, bigger lash pads, cams,valves and guides, as well as a hot cam shaved to 75 degrees for some awesomeness. And the best part? 700 bucks for the whole sha-bang. Quote Link to comment
I'm BLUE Posted October 30, 2012 Report Share Posted October 30, 2012 No, and I would tend to agree, but I have a second N47 head, which will be surfaced, get a valve job, aggressive port and polish, bigger lash pads, cams,valves and guides, as well as a hot cam shaved to 75 degrees for some awesomeness. And the best part? 700 bucks for the whole sha-bang. Well .. that's not bad deal at all considering what's being done. Are you going for high rpm ? Quote Link to comment
Dat Lurka Posted October 30, 2012 Report Share Posted October 30, 2012 That's for the whole engine right? That's a LOT of money just for a head job. Well, I'm thinking L20 so maybe it's not. Quote Link to comment
banzai510(hainz) Posted October 30, 2012 Report Share Posted October 30, 2012 SPROCKET HAS 2 SETTINGS Yes, #1( O degree) #2(4 deg) and #3 (8 deg) ask a Z car car whats the best setting. most times the sprocket is set to 1 then if chain stretch you can move it to #2 and so on. But if you want power sooner on a new timming set you move the sprocket up 1 number.thats the rule of thumb Quote Link to comment
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