|05-20-2013 07:45 AM|
|Dougie||Update. I haven't driven it because the front clip is off, but it seems to be running great now. I adjusted valves one by one using the method that puts the lifter on the bottom of the lobe. I also got the timing dialed in at 20 degrees BTDC initial and it all comes by 2500 rpm (36 degrees). Starts right away and it idles with a nice lope at about 900 rpm. I can wait to drive it! Thanks for all the help.|
|05-05-2013 05:40 AM|
Great news, I've been following this thread. I'm sure you were second guessing everything you had done when building this. I've been there myself (I can imagine that most everyone has at some point as well.)
The 1st time I had the same exact problem you had, quite a long time ago, I ended up using a timing light while cranking. I had the same issue, off by one cylinder on distributor installation. Since then, I use a timing light on initial startup. It definitely eliminates all of the guessing of what exactly is happenning.
Good luck with your project!
|05-04-2013 08:23 PM|
YES!!! I got it running. I readjusted the valves using the up and down method on the pushrod and not spinning it. Now that I've done it both ways I can see how the spinning method could be misleading. More importantly, I think the real issue was the timing. I was trying to start it around TDC because that's what many posts said should work to get it going. It started but ran very rough. I immediately advanced it quite a bit and it smoothed out. After warming up, it seemed to like about 12-14 degrees BTDC.
Ran it for 25 minutes between 2000 and 2500 rpm in the garage with a box fan in front of the radiator to break in the cam. The whole time the oil pressure never fell below 45 lbs. and the temp never rose above 200 degrees, so I feel really good about this, and no leaks.
Next change the oil and filter and run a little more before putting the front clip on so I can take it for a spin. Thanks everyone!
|05-02-2013 03:08 PM|
|Too Many Projects||
|05-01-2013 09:19 PM|
|bygddy||And do you have the pn# for the cam handy? Perhaps a stupid question but you didn't end up with a 5-7 swap or anything?A|
|05-01-2013 09:15 PM|
|bygddy||Try dropping a touch of oil down the plug holes and then confirm your dist is right, and start over. I'm wondering, and could be dead wrong, but if you had exsessive cyl wash and have no compression on multiple holes it would run as poor as you described or not at all. You mentioned you had seen fuel, I'm just wondering if it was too much on fresh walls and rings and its not sealing worth a damn.|
|05-01-2013 08:54 PM|
|Dougie||Someone needs to close his gap. (For the record, plug gaps are fine)|
|05-01-2013 07:48 PM|
|bygddy||So am I the only one who found the last 5 posts (nope, not spinn's) more then slightly creepy?|
|04-30-2013 10:30 AM|
|spinn||The engine wont start and you came up with the plug gap closed? Yeah , that will do it but he confirmed spark.|
|04-30-2013 09:25 AM|
|Hot Parts||Check plug gap. Pistons may have come up & closed them. I did this on a high compression motor once $ it does fire & then dies. I also was confused at time until I found it out.Gods love be with you.|
|04-30-2013 08:23 AM|
|496CHEVY3100||You use a priming tool to fill the lifters and prime oil to the bearings so it wont have a dry start and destroy bearings and cam, if you prime it first you can adjust rockers with valves closed until contact with rocker + 1/4-1/2 turn Chevrolet recommends 1 full turn with GM lifters and cam,but there cam is rated a 6 and after market is rated at ,50 so if you use gm recommendation on aftermarket can vales will be to tight it will cause low vacumn or no start .But if lifters are DRY NOT pumped up it takes1-1/4 rounds to bottom a lifter from first point of contact so if you bottom out lifter then back it up 3/4 round you are at 1*2 round down THEN you use a priming tool to fill lifters until oil comes out all rockers ,while priming turn engine 90 degrees to alow oil to all passages this is the most accurate method since there is no guessing or you can use a dial indicator or your method which ever you choose ,I would use the one that you like best ,I was just giving you an option ,but on hundreds of racing engines and mant street engines i have never had but one flat cam,dont think it was due to miss adjusted valves.These are a couple of championship cars the #76 Modified ,#3Limited class,66 a hobby stock rebuild only,77 crashed before season end.|
|04-29-2013 11:16 PM|
|spinn||Yeah if you bottom them out with just a turn back, how will they pump oil up to fill. That plunger acts as a suction pump to pull oil into the lifter.|
|04-29-2013 07:34 PM|
|04-29-2013 07:13 PM|
|richard stewart 3rd||
I'm sorry for not being clear on the subject.
The intake & exhaust on each cylinder your
doing do get adjusted at the same time.
I will be more careful in the future.
|04-29-2013 11:01 AM|
It may be possible for a rookie to have the finger and thumb "feel" necessary to use the "spin the pushrod" method and get the valve adjustment correct, but 99 times out of 100, the valves will end up too tight as related above. Please read through this tutorial and implement its instructions. It's pretty much bulletproof and I have received PM's from many fellows saying so....
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