Heads info
Thread Starter
|
New User
Joined: Mar 2007
Posts: 13
Likes: 0
Heads info
I haven't posted in a while because all my tools were in storage with Atlas Van Lines.
I bought a home and my goods will be delivered on the 21st.
I am very excited to get back to work on my truck.
Questions;
I can get a set of 1990 heads off a 302 engine, will they interchange on my 1970 302 cid?
How about the exhaust manifolds.
All this is off a 1990 Bronco which I can get for free. The engine is 'supposedly' good, just the transfer case is toast. The guy towed it with the case in gear.
Reason I ask is I have a 'miss' I am guessing is a burnt valve. I replaced the carb and dist and wires and I have an inconsistent 'pop' about every 15 seconds at idle. Idle is rough, but at 15 mph it clears up and runs great.
The engine has not used any oil yet so I figure it is worth a lil work to get it right.
Thanks for listening; Dave
I bought a home and my goods will be delivered on the 21st.
I am very excited to get back to work on my truck.
Questions;
I can get a set of 1990 heads off a 302 engine, will they interchange on my 1970 302 cid?
How about the exhaust manifolds.
All this is off a 1990 Bronco which I can get for free. The engine is 'supposedly' good, just the transfer case is toast. The guy towed it with the case in gear.
Reason I ask is I have a 'miss' I am guessing is a burnt valve. I replaced the carb and dist and wires and I have an inconsistent 'pop' about every 15 seconds at idle. Idle is rough, but at 15 mph it clears up and runs great.
The engine has not used any oil yet so I figure it is worth a lil work to get it right.
Thanks for listening; Dave
Hotshot
Joined: May 2004
Posts: 12,170
Likes: 5
From: The hills of No. Calif.
Dave, the later heads will bolt right up and either head/manifold comb will interchange, as there were virtually no significant changes made to exhaust manifold bolt patterns over the years.
That said, I'm not sure I agree with your diagnosis. A burnt valve will cause a loss of compression in that cylinder (and therefore a miss) that won't improve. I'd do a compression check, and have a look at the plugs while you're at it. It almost sounds like a partially fouled plug.
That said, I'm not sure I agree with your diagnosis. A burnt valve will cause a loss of compression in that cylinder (and therefore a miss) that won't improve. I'd do a compression check, and have a look at the plugs while you're at it. It almost sounds like a partially fouled plug.
Thread Starter
|
New User
Joined: Mar 2007
Posts: 13
Likes: 0
Plugs?
Thanks, I am going nuts on this thing!
New Carb and new point distributor, Just changed the plugs today and all 8 of the old ones looked GREAT. Using AC 25 peanut plugs, same as came out. All 8 plugs were a little on the white side but not too much.
Is it possible that the fuel filter on the pump is clogged? I thought not since it runs great after 15 mph. I was thinking if I starved the carb at idle it would get worse on acceleration? I have not changed it yet and it looks OLD.
Timing is strange though, If I advance all the way til it hits the Water outlet it runs best. But, It never 'bumps' the starter (as in too far advanced).
Do you think I could be one tooth off on the dist gear?
Thanks! Dave
New Carb and new point distributor, Just changed the plugs today and all 8 of the old ones looked GREAT. Using AC 25 peanut plugs, same as came out. All 8 plugs were a little on the white side but not too much.
Is it possible that the fuel filter on the pump is clogged? I thought not since it runs great after 15 mph. I was thinking if I starved the carb at idle it would get worse on acceleration? I have not changed it yet and it looks OLD.
Timing is strange though, If I advance all the way til it hits the Water outlet it runs best. But, It never 'bumps' the starter (as in too far advanced).
Do you think I could be one tooth off on the dist gear?
Thanks! Dave
Hotshot
Joined: May 2004
Posts: 12,170
Likes: 5
From: The hills of No. Calif.
That could very well be. Sure seems like it if you can't get any more advance than that. And I'd still change the filter if it's old, but you're correct, a plugged filter would make the engine run worse as RPMs increase and it starves for fuel.
How about the points in that new distributor, are they set correctly? Checked for vacuum leaks around the base of that new carb?
If you have a vacuum gage, hook it up and check the readings and then compare them with the sample readings on this page:
http://www.users.bigpond.com/ergoff/vac1.htm
Another trick is wait till it's pitch dark outside and then start the engine and look under the hood with it idling to see if there's any crossfiring in the plug wires. If there is, you can tell instantly from the pretty light show.
How about the points in that new distributor, are they set correctly? Checked for vacuum leaks around the base of that new carb?
If you have a vacuum gage, hook it up and check the readings and then compare them with the sample readings on this page:
http://www.users.bigpond.com/ergoff/vac1.htm
Another trick is wait till it's pitch dark outside and then start the engine and look under the hood with it idling to see if there's any crossfiring in the plug wires. If there is, you can tell instantly from the pretty light show.
Last edited by TigerDan; May 13, 2007 at 09:22 PM.
Thread Starter
|
New User
Joined: Mar 2007
Posts: 13
Likes: 0
Miss
You know I never thought about the points. The distributor was put in new and the cap and rotor also by a Shop. I did not re-check the point gap. Should be about .017 if memory serves me. I will do that before I move the dist around.
I checked for vac leaks, the plug wires are new too.
I learned along time ago "make one change at a time" and check to make sure it still runs.
I'll keep ya posted after I work on it a bit this weekend.
Thank you!
I checked for vac leaks, the plug wires are new too.
I learned along time ago "make one change at a time" and check to make sure it still runs.
I'll keep ya posted after I work on it a bit this weekend.
Thank you!
Thread
Thread Starter
Forum
Replies
Last Post
Bullitt390
6.0L Power Stroke Diesel
17
Mar 11, 2014 01:45 AM
chewedtoothpick
6.0L Power Stroke Diesel
53
Aug 17, 2013 07:41 PM
TheDesertRat
1973 - 1979 F-100 & Larger F-Series Trucks
9
Oct 22, 2009 10:55 PM
