1679 First Startup Issues

[NewTechnicIan]

Hi all, been reading about the some similar cases but I figure I should put mine out there. I'm rebuilding my old dp 1600 case and upping it to 1679. You can check my engine build thread in my signature for a lot of details there, but I got it all put together for a first start last night and it was having trouble turning over

Electrical:, I think we're in good shape. Fresh battery (495 Cold Cranking Amps), fresh starter that was bench tested at advance auto ahead of time and looked great. I looked at the starter bushing ahead of installing the starter and it didn't look pounded out into an oval or anything so I don't THINK it's the starter getting a bad crank on the flywheel. Oh, also I'm just using an alligator clip from the starter to the coil rather than a thicker gauge wire and a spade connection if that is a factor for people.

Bearings: When I put the case together, I was SUPER CAREFUL to make sure the bearings were well seated, since I pinched a bearing during mockup earlier in the year. When I plastigaged my mains and cam bearings, they all came back as the low side of spec but within spec (Main bearings .002", cam bearings .002-.0025").

Assembly: When I put the case together, the crank spun smoothly, although with a little effort. It was easy with the pulley or flywheel but just turning the nose by hand took a little effort.

Then I put the whole thing together. Obviously it got a bit tighter when I put the cylinders on, and I need a wrench on the pulley to spin it now. It takes about 20 ft-lbs without the spark plugs to rotate the assembly and it takes up to 35 ft-lbs when building pressure with the plugs in.

I was reading some other articles that also made it sound like the engine should be loose enough that rotating the alternator pulley when it's adjusted correctly should rotate the engine. Is this a good measure? If so, it doesn't work for me.

I spun it up last night to see if I could get it going, and I got some sputtering but it didn't seem like it was spinning everything fast enough to really get going. The plugs were pretty dry even after trying to get it going for a while.

This being my first rebuild, maybe I missed something or maybe this is normal. Advice from all you fine folks would be great!

So do some engines on their first start just need to get going so they can seat everything and loosen up or is there more to worry about here?

Should I just hook up a big battery or a hard start relay to the starter to get it over that hump?

Thanks!
Ian
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My 73 Standard build - It's painted! It drives under its own power! Time to get it wired and upholstered!

My 1679 Engine build.

[67rustavenger]

Follow this word for word to get your engine started.
http://www.speedyjim.net/htm/eng_strt.htm
Good Luck.
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[NewTechnicIan]

67rustavenger, thanks for the link. I haven't checked compression so I should do that. Otherwise though, is it OK that the thing seems to be stiffer than i've seen other engines before and that it should break in nicely once it's been test-run?

Thanks!
_________________
My 73 Standard build - It's painted! It drives under its own power! Time to get it wired and upholstered!

My 1679 Engine build.

[bugguy1967]

As long as you checked all the clearances, you should be fine. It'll loosen up after start-up.

[mark tucker]

what did you do to the pistons&cylinders?
allso if it's spudering you may need to addvance the timing a tad. you should always spin the engine with sparking bolts out befor trying to start it the first time to get good oil pressure everywhere. and remember not all parts are pressure fed so asembly oil/lube is very importaint. be sure carb is good.dont wory about dry plugs.

[stan_tichomirov]

If plugs are dry you obviously aren't getting enough fuel. Mechanical pump? Nice thing about electrical pumps is they'll deliver fuel without having to spin the engine. Spray some starting fluid in the carb(s). May have to tweak the distributor orientation. Also, check the plug wires for being in correct order, I crossed 1/2 wires last week -- still make those mistakes sometimes.

Stan
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[toomanytoys]

Whats your endplay set at?

[NewTechnicIan]

I didn't double check after final assembly, so that might be worth checking out, but when I mocked the engine up ahead of time it was within spec at .003".
_________________
My 73 Standard build - It's painted! It drives under its own power! Time to get it wired and upholstered!

My 1679 Engine build.

[NewTechnicIan]

Ok, just tested compression.
#1-115 psi
#2-120 psi
#3-125 psi
#4-120 psi

So that looks good! I also just realized I've been using 89 octane and it's apparently ok to go higher with that. I always thought that's how you get detonation/power strok too early. Should I switch to a higher octane fuel in case it helps?
_________________
My 73 Standard build - It's painted! It drives under its own power! Time to get it wired and upholstered!

My 1679 Engine build.

[NewTechnicIan]

Holy cow, she started!!!!


In order to test compression, I ganged my car's battery and the new battery for the bug together to give the starter some more juice and I put some WD 40 in the cylinders to make sure they were travelling on some lubricant. That all started rotating so well as I was testing compression that I figured I should try starting her up again, just for grins.

There were some hiccups, like I accidentally had the fuel pump hoses reversed the first time it started so it only ran for 30 seconds or so, but once I got that figured out, she started up and ran!! With just the header and no muffler it sounded like a dirtbike

Unfortunately I had to hold the throttle way open to keep her running which I was worried by, and I saw the headers were getting really hot and I could even see some orange down the pipe on my header. This is a bugpack hideaway exhaust, btw, but I left the muffler off for the test run, so it was just the header. Anyway, I let up on it around 7 minutes in and it died, and now I'm not sure what to do next.

So what do I do now? I always heard to run it for 20 minutes, change the oil and adjust the valves and you were golden. I'm pretty sure it was my carb throwing me off with the mixture screws so I'd like to get those squared away and run it in correctly. Is it best to run it with the oil it has now or should I change the oil before that? Any tips for adjusting the carb or anything else I should know at this point?
_________________
My 73 Standard build - It's painted! It drives under its own power! Time to get it wired and upholstered!

My 1679 Engine build.

[mark tucker]

could be leen, could be vac leek ,could be ignition tyming. could be you need to find out.

[NewTechnicIan]

Mark, I'll definitely find out, I just want to make sure while I'm finding it all out that I'm being safe on the engine.

Since it's run for about 7 minutes at this point should I change the oil and filter or do I just keep the oil where it is until I have the thing tuned well enough for a fast-idle run in?

I want to make sure that during this fragile stage in its life my delicate lobes and lifters and cylinders, etc are well cared for
Thanks!
_________________
My 73 Standard build - It's painted! It drives under its own power! Time to get it wired and upholstered!

My 1679 Engine build.