Help starting my new rebuilt engine

[Razorbackbronco]

Hey guys I need a little help. I'll make a long story short to get you up to date. I bought a completely rebuilt 302 out of a 68 mustang back in the summer to put in my 76 ranger. I got it installed and got to the point a couple of weeks ago to fire it up. I started it right up and was putting a break in cycle on it when less than 1 minute into it I heard a huge crash. Well, the guy I bought it from had dropped a 5/16x3/4 bolt into the intake and it got sucked into the number 4 cylinder and broke the piston in two and also cracked/caved in the cylinder.

Sooo, about a grand later I have machined my original block, and purchased new piston/rings. I have spent the last week pulling the old engine and changing all the internals that were still good over to the new block. I got it all installed with new rings and gaskets and put in the bronco this week.

I went to start it last night and it won't start. It doesn't turn over near fast enough, nothing like before the rebuild. I have a 69 with a 302 and they are both very similar to each other as far as turning them over with a 15/16 socket on the front pulley.

My first thought was to replace the starter, so I had one laying around and I put it on. It was exactly the same sound and speed as the other. I then pulled all the spark plugs to see if it might have trouble turning over because of high compression, but it was the same. I have checked my ground from battery to body, and ground from battery to engine.

It has a C4 tranny and when I bolted the tranny up it went it very smoothly to the torque coverter and turns without anything binding up.

I plan on taking the starter to O'Reillys tomorrow to check it. I just find it unlikely that two starters would be bad, especially one that was working fine just before I took it off to rebuild the engine.

Anything jump out at you guys? Thanks!

 

[Fairlane514]

Is it grunting like you have too much timing advance? Or just turning very slowly?

 

[jasonb]

When you reassembled the bottom end, are you sure you didn't get any of the main or rod caps mixed up or installed backwards? Are all the rod and piston assemblies installed on the correct side of the engine? If the rods are backwards on the crank, the rod bearing will ride on the fillet or rounded edge of the crank journal and can bind. Also, make sure the cam turns freely. With the plugs out, the engine should turn over quite easily with a ratchet.

 

[broncnaz]

X2 could have to much timing

 

[Razorbackbronco]

Well, I pulled the plugs, wires and dizzy cap and it cranks the same as before, so it can't be timing. When I was assembling the timing chain I lined up the two gears the exact way the book said and the timing marks are lined up perfect.

I was very, very careful to make sure all pistons and rod caps were put facing the correct way.

I can turn the engine over with a 1/2 rachet fairly easily, so I don't think its internal. I am going to get my torque wrench out and compare how many ft/lbs it takes to turn over this engine compared to my 69.

 

[Razorbackbronco]

I'm thinking it could be grounds? I have a ground from the battery to the block, a ground from the battery to the body. Do I need a ground from the body to frame? Or maybe a ground on the tranny?

 

[Ourobos]

What were the clearances on your rod and main bearings? What is the compression ratio?

 

[Viperwolf1]

When's the last time the battery was charged?

 

[Broncobowsher]

When's the last time the battery was charged?

That is what I was thinking as well

 

[bmc69]

I can turn the engine over with a 1/2 rachet fairly easily, so I don't think its internal. .

I agree with that assessment..

All things point to a lack of cranking oomph.

 

[Razorbackbronco]

When's the last time the battery was charged?

I charged it all yesterday, and while it was cranking. I then pulled my battery out of my 69 and tried it but it is still the same.

How many volts should I be looking at the starter terminal while it is cranking?

 

[Broncobowsher]

you should have less then 1 volt drop across the cables and connectors. Put the leads of the volt meter across the battery and read the voltage WHILE CRANKING. I do expect to see that to drop a little while loaded, say 11V. If it goes single digits it is either a weak battery or a huge current draw. Put the leads of the volt meter on the starter (case and starter post) and read voltage. If that is more then a 1V drop then you have bad power and/ground issues. Amazing how a coat of paint insulates, or how 2 pieces of big metal touching each other don't do a good job conducting electricity.

Lets say you do find low voltage at the starter, call it 6V. With a 12V battery there is a 12V drop in the circuit. You accounted for 6V of it in the starter so there is another 6V of drop in the loop that needs to be chased down. Put the volt meter on the starter case and the battery ground post and load the starter again. The higher the voltage reading, the more you found the problem. You can narrow it down by using the meter to bridge narrower gaps, say the battery post to the battery terminal. Yes that can be the issue. Every link of the chain. You don't need to check every link one by one, check one half and if it is good all those links are good, go to the side that is bad. There may be more then one bad link, so after you fix the real bad one it is a good idea to go back and check the whole chain again.

Remember to check both the power and ground.

 

[Razorbackbronco]

you should have less then 1 volt drop across the cables and connectors. Put the leads of the volt meter across the battery and read the voltage WHILE CRANKING. I do expect to see that to drop a little while loaded, say 11V. If it goes single digits it is either a weak battery or a huge current draw. Put the leads of the volt meter on the starter (case and starter post) and read voltage. If that is more then a 1V drop then you have bad power and/ground issues. Amazing how a coat of paint insulates, or how 2 pieces of big metal touching each other don't do a good job conducting electricity.

Lets say you do find low voltage at the starter, call it 6V. With a 12V battery there is a 12V drop in the circuit. You accounted for 6V of it in the starter so there is another 6V of drop in the loop that needs to be chased down. Put the volt meter on the starter case and the battery ground post and load the starter again. The higher the voltage reading, the more you found the problem. You can narrow it down by using the meter to bridge narrower gaps, say the battery post to the battery terminal. Yes that can be the issue. Every link of the chain. You don't need to check every link one by one, check one half and if it is good all those links are good, go to the side that is bad. There may be more then one bad link, so after you fix the real bad one it is a good idea to go back and check the whole chain again.

Remember to check both the power and ground.

Good info, thanks!

 

[Razorbackbronco]

An update:

I took my starter to O'Reilly and had it checked and it passed, which I expected it to do. I bought a multimeter and here are some numbers I have:

-across the battery terminals I have 12.63v
-Also have 12.63v from positive batt terminal to the alternator and to the starter post. All of those readings without cranking with key off.

-Battery drops to 11.05v while cranking.
-While cranking, I get a reading of 10.79v with one end on starter case and the other on starter post.
-While cranking it read .44v when I had it hooked up to the positive battery post and to the starter post.

Do any of these numbers seem right or wrong?

I also got out my torque wrench and turned the engine over with just 55-60ft/lbs which is right about the same as my 69, so I think we can rule out anything internal. I also have a new neutral safety switch that I'm going to put on because the old one was pretty melted and frayed. Could this be it?

Also bought another cable that I was planning on grounding the engine to the frame as I only have 2 grounds right now, 1 from the neg batt post to the block, and the other from the neg batt post to the front part of the body.

 

[Viperwolf1]

I also have a new neutral safety switch that I'm going to put on because the old one was pretty melted and frayed. Could this be it?

No. If the starter solenoid is engaging now it can't engage any better with a new NSS.

How about a video that shows how slow this thing is actually cranking?

 

[broncnaz]

Maybe the engine was built with high compression pistons. That could cause slow cranking. you might need to step up to the newer style gear reduction starters for more omph.

 

[Razorbackbronco]

Ill get a video in the morning viper. I used the same pistons that it had before

 

[Razorbackbronco]

Here is a video. I took the ps and alt belt off earlier to see if that would help to turn it over better, so that's why the fan isn't spinning.

I took the dizzy cap off to give a reference on how fast it's spinning while cranking.

http://m.youtube.com/watch?feature=...ch?v=UmJKOVXzKMI&feature=youtube_gdata_player

 

[Fairlane514]

It sounds like you have no compression. It does turn slow, but still…..I would run the valves again.

Can you feel air escape from a cylinder if you remove a spark plug while cranking?

 

[PaveBronco]

Just a long shot? did you put the 68 heads back on? I just ran into a situation where I scored some ported 68 mustang heads and didn’t realize that they didn’t have positive stop rocker arm studs. So I ended up torqueing them down too much so the valves didn’t ever close...so no compression or start....if you don’t have spark at the plugs, may be that...?