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| jaa1992 | Help LTx 383 build cam issue | ||
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Guru
 
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Putting the 383 together
Put the cam in befor the crank and rods cam turned freely, I guess I turned that sucker 20 times. Put the bottom end together and installed the gear on the crank. put the water pump gear on and the cam gear Could only rotate the cam gear about 350* in either direction. tried another waterpump gear - same thing What the heck is going on??? took the water pump gear out and sure enough the cam only rotates and then STOPS what the heck did I do wrong? It shouldn't touch the rods so that can't be interfering - can they? Help!! |
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Posted on: 2012/5/6 22:35
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| 92Polo | Re: Help LTx 383 build cam issue | ||
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Actually YES the cam can hit the rods depending on your cam and rod choice. You may have to get what is called a small base circle cam. Rotate the cam until it stops and mark it's position. Then rotate the crank slightly and see if it changes how far you can turn the cam. Bet it does.
BTW it's possible that if the cam and bottom end are turning together that it won't hit. Just have to put the timing chain on it and slowly turn it over and see what you get. |
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Posted on: 2012/5/6 23:22
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| bogus | Re: Help LTx 383 build cam issue | ||
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hence forth, timing.
If the timing is on, all should be ok, if off... I don't think grinding on the cam is advisable. |
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Posted on: 2012/5/6 23:27
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The single biggest problem with communication is the illusion that it has taken place. - George Bernard Shaw Education is the best tool to overcome irrational fear. - me |
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| Calm | Re: Help LTx 383 build cam issue | ||
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Polo's right. Looks like you'll need a 'small base circle' cam, providing the timing chain was installed correct. It's not unusual, I'm told, that most stroker small blocks need the extra clearance. Mine did.
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Posted on: 2012/5/7 0:16
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1995 Forged 385 ZF6 227/234 1.6 FIC30# MSD BBK SS SLP Bullets X-Pipe DynoMax |
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| jaa1992 | Re: Help LTx 383 build cam issue | ||
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Its an LT4 hotcam, which IIRC is a small base circle.
so I'll try rotating the crank a little and see if the interference changes. Off to put an old hub on and a bolt to turn the crank. Thanks for the update. |
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Posted on: 2012/5/7 0:49
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| 92Polo | Re: Help LTx 383 build cam issue | ||
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I'll be curious to see what type of power you make with that cam on a 383. I love the cam on my 350 although it does give up a little bit of low end, it's still pulling hard to 6500. The stroker should gain back the low end, if the cam / heads can flow enough up top it should be awesome.
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Posted on: 2012/5/7 13:50
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| rklessdriver | Re: Help LTx 383 build cam issue | ||
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I would line up the timing marks and install the chain. The flip the engine upside down and watch (from the bottom) the lobes for contact with the rods as you turn it over slowly.
If one hits pull that rod and grind on the shoulder until it clears.... It's not a big deal, depening on what rods you have... People building 3.75 stroke engines have been doing it forver. Will |
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Posted on: 2012/5/7 19:32
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1984 Corvette. 434 SBC with a Powerglide. Best pass - 8.48@160MPH 1.23 60ft on MT 275/60R15 Radials. 1972 Corvette. LS5 454 BBC with M20 4 speed. Best Pass - Doing good to just pass a gas station. |
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| EngineDoctor | Re: Help LTx 383 build cam issue | ||
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Here is where I believe u may have gone wrong,you did not Pre-Assemble!!!
This is how I do it... 1. Install cam check the fit etc. 2. Install the crank,rotate & check crank counter weights to block & oil pump clearances. 3.Install timing set / degree cam in. 4. Take and install ONE (with out rings)piston & rod assy and install it in cylinder bore, with crank facing you, look for,rod to block clearance,piston to crank counter weight clearance, rod to CAM clearance. ETC Use can use the same piston and rod assy to check all 8 cylinders. Clearance as needed, when all done, take back apart and then you can procede to Final assembly. BTW only use engine oil for pre-assy , No assy lube. Depending on parts combo, lots of clearancing may need to be done. The pre-assy stage saves lots of potential problems....Good luck.... , jus my 2 cents  ALSO CHECK FOR CRANK COUNTER WEIGHTS TO OIL PAN FOR CLEARANCE....there I dont think I left anything out |
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Posted on: 2012/5/7 22:05
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| jaa1992 | Re: Help LTx 383 build cam issue | ||
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Carp - why isn't this in the books and articles I read a hundred times
 Any concerns with balance if I grind the rods for clearance? Crank was balanced to the current rods and pistons. Any concerns with the piston going up and down in the cylinder without rings? Guess its time to pull it all apart again Block is clearanced and the crank weights and rod ends have lots of room. Thanks again to ALL!!!! |
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Posted on: 2012/5/7 22:28
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| jaa1992 | Re: Help LTx 383 build cam issue | ||
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OBTW - I'm class limited on HP which is why I went with the lt4 hotcam. I'll have to look, but IIRC its 350rwhp
Now if I wind up over that and can't detune I'll be looking for a wilder cam to run in the next class up. |
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Posted on: 2012/5/7 22:32
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| rklessdriver | Re: Help LTx 383 build cam issue | ||
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Not a problem with the piston having no rings for mock up.
You won't take enough off the rod to make a difference in the balance. Will |
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Posted on: 2012/5/7 23:42
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1984 Corvette. 434 SBC with a Powerglide. Best pass - 8.48@160MPH 1.23 60ft on MT 275/60R15 Radials. 1972 Corvette. LS5 454 BBC with M20 4 speed. Best Pass - Doing good to just pass a gas station. |
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| EngineDoctor | Re: Help LTx 383 build cam issue | ||
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Quote:
YOU did nothing wrong Look at it this way, to build any engine properly you need to Assemble it at least twice, even if stock ! The reason for the Pre-assy is to establish proper oil clearances, parts clearancing,cc'ing for desired compression ratio,and checking valve train geometry etc. It assures a bullet proof final assembly, and yes it takes alot more work but it pays of at the end! As far as NOT installing the rings , that is done for a smoother feel as you rotate assy over, no reason to have rings dragging in there at this time, and secondly you won't have to be rebalancing anything if you need to clearance the rods for the cam and so dont worry about that. It is best to do all your pre-assembly build first and when all is good, THEN have your parts balanced.. you'll b ok.Attach file:  jeans.jpg (56.88 KB) |
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Posted on: 2012/5/8 0:03
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| jaa1992 | Re: Help LTx 383 build cam issue | ||
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ok, pistos/rods are out
Timing set is on - I can't beleive I got the marks lined up perfectly the first time! Chain is a little loose, but I can adjust it later with some help. I couldn't get the bolts tight, chain tight at the same time. Tomorrow night I'll do one piston in each hole and rotate a couple times to make sure there is no rod interference. Mark the rod if there is and hit it with the grinder - reminds me I'll pick up an electric grinder tomorrow cause I don't think the dremel will cut it and my compressor won't put out enough air to make the one I have run for more than a couple seconds |
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Posted on: 2012/5/8 1:56
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| Churchkey | Re: Help LTx 383 build cam issue | ||
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Suggest a length of .030 or .035 MIG welding wire to gauge clearance.
GL |
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Posted on: 2012/5/8 16:11
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| rklessdriver | Re: Help LTx 383 build cam issue | ||
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I use a bench grinder or belt sander to clearance rods.... Your only grinding on the rod shoulder or bolt head (depending on what kind of rod you have).... Here are a few pics I grabbed off the web of different types of rods and the amount of grinding done... as you can see, it's not a whole alot. [img width=300]http://t3.gstatic.com/images?q=tbn:ANd9GcSvQWhS1AAF1gxcQ3d9w9gQyQdYsoyae2t18R2F[/img]    BTW Number 1 and Number 5 are the most common rods to hit the cam. Will |
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Posted on: 2012/5/8 16:59
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1984 Corvette. 434 SBC with a Powerglide. Best pass - 8.48@160MPH 1.23 60ft on MT 275/60R15 Radials. 1972 Corvette. LS5 454 BBC with M20 4 speed. Best Pass - Doing good to just pass a gas station. |
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| EngineDoctor | Re: Help LTx 383 build cam issue | ||
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X2 on the # 1 and # 5 rods .
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Posted on: 2012/5/8 17:31
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| flyboy | Re: Help LTx 383 build cam issue | ||
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Could you clarify this for me? First you wrote that it's OK to grind on the rods and not rebalance anything, afterward you stated to finish the "pre-assembly" and then balance the parts. Thanks |
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Posted on: 2012/5/8 19:55
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| EngineDoctor | Re: Help LTx 383 build cam issue | ||
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Glad to.. In this case it appears that all he needs to do is clearance the rods to clear the cam lobes, that should be a minimal amount of material to remove, and probably on just a couple of rods.He should be okay. The way it should have been done is to pre-assemble clearance everything, take back apart and then procede with the balancing of the rotaing and reciprocating assy. |
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Posted on: 2012/5/8 22:20
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| jaa1992 | Re: Help LTx 383 build cam issue | ||
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Well, aparently the rods are clearanced enough from the original build. I think I forgot to mention this is a rebuild of a 383 that decided to thow a lifter into the cam grea and carnage ensued.
Been trying to get enough time to assemble this for a couple of months. Been spending an hour here and there. Anyone reading this in the future - follow engineholic's method of checking the clearance! Putting the timing gear together is PERFECT! Now I have a stinking rod bolt that fell into the cam area when I was removing it from #2 piston. I've tried different magnets and other tools to try and get it out. Looks like I'm going to need to remove the timing, cam gear, cam retaining plate, and pull the cam to get it |
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Posted on: 2012/5/8 23:46
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| EngineDoctor | Re: Help LTx 383 build cam issue | ||
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I'm sorry for any confusion I may have caused, just trying to help without you getting into more expense, and thank you for your kind remark Jaa1992! Question for ya though ... Have you got pressed on pistons or floating/bushed rods with locks ?? |
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Posted on: 2012/5/9 0:48
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| jaa1992 | Re: Help LTx 383 build cam issue | ||
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Floating pistons with locks.
didn't take the piston off the rod, well my machinist that balanced the crank did and put them back together. |
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Posted on: 2012/5/9 0:56
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| EngineDoctor | Re: Help LTx 383 build cam issue | ||
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OKAY GOOD THAT U HAVE FLOATING, WHEN U R DONE CLEARANCING, TAKE UR ASSY BACK TO UR MACHINEST TO CHECK OUT THE BALANCING .. I was worried u had pressed on pistons and they can be damaged when pressing back off. I am sure after clearancing, you will not be more than a couple grams off, if even that |
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Posted on: 2012/5/9 2:00
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| jaa1992 | Re: Help LTx 383 build cam issue | ||
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The good news is with the timing gear and chain there was no interference so I didn't have to clearance the rods or rod bolts anymore.
Tomorrow night its pull the camshaft and recover the bolt and start putting it together for final assembly. It ain't gonna be in the car on Saturday so I gotta figure out plan C for the weekend I'm instructing at Atlanta Motorsports Park |
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Posted on: 2012/5/9 2:39
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| Calm | Re: Help LTx 383 build cam issue | ||
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Quote:
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That's great news! Sorry about the lost bolt. Perhaps use your magnet while rocking the cam a little back and forth? Best of luck! |
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Posted on: 2012/5/9 3:27
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_________________
1995 Forged 385 ZF6 227/234 1.6 FIC30# MSD BBK SS SLP Bullets X-Pipe DynoMax |
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| 1Fast04Vert | Re: Help LTx 383 build cam issue | ||
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Elite Guru
 
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Jim, I just sent you a private message about AMP.
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Posted on: 2012/5/9 12:37
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2004 Vert. 475hp. Built by Vengeance Racing |
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| jaa1992 | Re: Help LTx 383 build cam issue | ||
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Tried that, I've got three diferent "magnet on a stick" tools and none of them helped. Hoping just pulling the cam out a little will do the trick. |
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Posted on: 2012/5/9 22:28
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| jaa1992 | Re: Help LTx 383 build cam issue | ||
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Gotcha covered. They are going to let Instructors hit the track Friday so I'll get a little time then. I've got to get this engine together - tonight is get the nut out, put timing set back on and maybe pistons - we'll see. |
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Posted on: 2012/5/9 22:31
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| jaa1992 | Re: Help LTx 383 build cam issue | ||
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Had to pull the cam all the way out to get that stinking nut So cam gear and chain off, cam retainer off, cam out, bolt recovered, cam lubed, cam in, cam retainer on, cam gear and timing chain on. 6 pistons in and snug on the rod bolts. Tomorrow night is last two pistons and torque rod bolts. Then oil pump and hardware. Make sure it spins freely. then I'll test fit the champ pan and pickup. That will be all until Monday night cause I'll be wore slam out keeping my student from killing me at the track |
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Posted on: 2012/5/10 2:04
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| 1Fast04Vert | Re: Help LTx 383 build cam issue | ||
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Have fun at AMP tomorrow. I got to run some fun laps out there last week after working on getting the track ready. I was the only car on the track and got to 'learn' a bit about driving it. Coming off the straight by the pits downhill into a 270* turn is going to be challenging for some. |
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Posted on: 2012/5/10 14:51
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2004 Vert. 475hp. Built by Vengeance Racing |
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