LSX is ready to be dropped in tomorrow (PICS!)
09-12-2008, 02:18 PM
#621
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a compression guage is good to have for sure. you may as well get a new MAP on your way home too. that little diaphragm inside of it is SUPER sensitive, much like the element on a MAF sensor. if your intake did fill up with liquid, sludge, and/or metal debris...there is a 99.9% certainty your MAP is fucked...and being a SD motor, that's a pretty critical sensor.
09-12-2008, 03:52 PM
#622
a compression guage is good to have for sure. you may as well get a new MAP on your way home too. that little diaphragm inside of it is SUPER sensitive, much like the element on a MAF sensor. if your intake did fill up with liquid, sludge, and/or metal debris...there is a 99.9% certainty your MAP is fucked...and being a SD motor, that's a pretty critical sensor.
09-12-2008, 04:28 PM
#623
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I'm betting also that its not getting fire. Sounds just like mine did when cranking it over with the coils unplugged. Good luck with it man, I know how frustrating it can be.
09-12-2008, 04:40 PM
#624
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I'm on board with Fier67 on this one. It sounds alot like a friends vehicle that had a low impedence injector box wired up to the wrong injectors. Double check that crank ring and make sure it's on right or that it's even the right one. Also be careful how much fuel you dump in the cylinders or your gonna get cylinder wash and you rings will never seal.
09-12-2008, 05:56 PM
#625
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The compression test was interesting to say the least. Unless I was doing it wrong, I got a whole 0 lbs of pressure! I put it in the spark plug hole, unplugged the coils, took out the injectors fuses and cranked it over for about 3-5 seconds and got nothing and then tried another 3-5 seconds and still nothing.
I'm going to get a pushrod length checker tomorrow. Is it even possible to have a 7.4 pushrod be that much too long to cause 0 pressure? I took the coils and valve covers off after that. I also took off the two rockers on the cylinder I'm pressure checking. It's real hard to tell by the eye but it looked like the valves may have came up a touch when I loosened the rocker arm. I'll take a pic to show.
Now can I do a pressure check with the rocker arms off to make sure the valves are sealing? It seems like it wouldn't work because there is no where for the air to move so unless that piston is all the way down, it wouldn't be an acurate reading?
On a good note, I got my blower belt in and it's huge and fits great. I'm going to install the tensioner and then post some pics. At least my cog set-up came out awesome, it sould be solid. Now if I only didn't **** up the engine side of it I would be ready for some dyno tuning next week.
I'm going to get a pushrod length checker tomorrow. Is it even possible to have a 7.4 pushrod be that much too long to cause 0 pressure? I took the coils and valve covers off after that. I also took off the two rockers on the cylinder I'm pressure checking. It's real hard to tell by the eye but it looked like the valves may have came up a touch when I loosened the rocker arm. I'll take a pic to show.
Now can I do a pressure check with the rocker arms off to make sure the valves are sealing? It seems like it wouldn't work because there is no where for the air to move so unless that piston is all the way down, it wouldn't be an acurate reading?
On a good note, I got my blower belt in and it's huge and fits great. I'm going to install the tensioner and then post some pics. At least my cog set-up came out awesome, it sould be solid. Now if I only didn't **** up the engine side of it I would be ready for some dyno tuning next week.
09-12-2008, 06:01 PM
#626
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I'm on board with Fier67 on this one. It sounds alot like a friends vehicle that had a low impedence injector box wired up to the wrong injectors. Double check that crank ring and make sure it's on right or that it's even the right one. Also be careful how much fuel you dump in the cylinders or your gonna get cylinder wash and you rings will never seal.
09-12-2008, 06:15 PM
#627
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I'm wondering if maybe my engine builder cleaned up the deck on my block and either I forgot he mentioned it or he didn't mention it? That could make the stock length pushrods too long. Also, here's my cam specs: 246/250 .632/.635 on a 112+4 Not exactly mild.
Here's the pics, hard to tell from pictures but maybe someone with more experience can see more than me?
Here's the pics, hard to tell from pictures but maybe someone with more experience can see more than me?
09-12-2008, 08:11 PM
#630
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ls1 346 to lsx 402 = +.015 per dirty
mls gasket .05 I think to cometic .04 = -.01
232/234 .598/.598 112 cam to 246/250 .632/.635 on a 112+4 cam = ?
Stock lifters to cadilac lifter = ?
Stock rockers to harlan built stock rockers = ?
Same heads
Without knowing the ?s it's hard to say but it doesn't seem like I should need shorter pushrods unless that monster cam has a larger base circle or something. I can't remember if that's what it's called but a cam can make you need a different pushrod if I remember right. It's been a while since I did cam research but that's the only reason I can see.
How else could I get 0 compression other than too long of pushrods?
09-12-2008, 08:16 PM
#631
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Well, whatever the reason, I'm going to make sure my pushrods are perfect now either way. Now I just need to figure out how to find the right length with the push rod checker. I researched it before and it seems like there is a lot of opinions on it, that's actually part of the reason I just went with stock length. Is there a correct way to do it or do I have to guess on who to listen to lol.
09-12-2008, 08:45 PM
#632
compression do the compression test with the rockers off of a cylinder if you got compresson your pushrods are way to long and holding the valves open or your cam timing is way off
pushrods gotta be too long. 
I feel some what accomplished 
09-13-2008, 04:35 AM
#636
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just check your pre-load and let us know what it is. The LSX deck is taller but I'm sure your machinest shaved it down some. Your base circle is probably smaller than stock. Now the caddy lifter i have no idea. Again, just make sure your pre-load is good. Whats the preload spec on the caddy lifters ?
