Camel Joe Bronco 78

[Dust]

Original Distributor?
Vacuum Advance connected correctly?
What Pplugs?
What Intake Manifold?

[[HBW]22]

Distributer is a Mallory unilite.
Vacuum advance is hooked up to where Holley says it should on the carb.
I have no clue what plugs but they are stock ones from motorcraft.
And intake is a Edelbrock Performer.

[Dust]

FWIW:
The 351-400M engines have open chamber canted valve heads. Unless the chambers are polished these heads are prone to detonation compared to their contemporary wedge heads. For this reason total timing should be limited to about 34°.
It would be nice to dial in about 14° initial but often that creates a problem with detonation at low RPM/High Load, I have found that 12° works with regular pump fuel. The classic HiPro timing curve was developed in a Wedge Head and again while it would be desirable to have as much initial lead and the remainder of the total all in by 2000-RPM in these 335-series engines it is better to have the full amount by 2500 – 2700 and the curve be a slow initial and an increasing rate. Most tuners don’t understand how to develop that and it is a pain so, limit the total, get the initial and then play with the mechanical advance rate until you get the best compromise.
I am not certain if the Mallory VacAdv is adjustable If it is then disconnect and plug it, set the mechanical first and then bring the Vac back and check how much it is adding and how fast. I’ve seen VacAdv cans bring in 60° which is WAY too much. How much? That takes experimentation and time to find, generally not more then 40° Maximum, you can get away with this because where there is maximum vacuum there is minimum load.

Spark Plugs in the flavor you like, the Motocraft is fine, but change them to one heat range colder. This will help with the engine’s tendency to detonate but not lead to fouling (assuming the Carb is correct).
The 400 and the Holley… First is the EGR there? I’ll guess not.
I found that adding a 1” thick 4-hole Carb spacer makes tuning almost any Carb running this intake easier and makes more power. You say the Carb is one of the truck avengers but without the list number to tell specifically which one …
Generally you should check the power valve if the engine backfires even once.
You should not delete the power valve
You should install a Backfire check valve if this Carb does not have one.
You have to set the idle AF (the needle valves) before any jet changes and recheck after every change the same holds true with the Squirter(s).
Make certain that the Accelerator Pump Check ball is in place and functioning.
Changing the AccelPump Nozzle has the following effect Larger = slightly higher volume, slightly faster and the total time of the shot is shorter. Without question you need some volume but in the 400 you also want the longest shot you can get, so you need the smallest nozzle possible for a given cam.
If the Carb is not new you should inspect the throttle shafts for wear.
A reset back to the Holly Original Build specifications may be a good idea if you picked the Carb up used.
Double check every hose and gasket for vacuum leaks, be careful!
Adding a couple of these (1 if single exhaust 2 if true duals) in a place where they can be seen will make life simpler in the long run: http://www.jegs.com/i/Sunpro/885/CP7011SW/10002/-1
A large face undampened Vacuum gauge is a good thing for tuning also.
So much for my opinion.

[[HBW]22]

Thanks for all that info man! Just trying to learn all this tuning stuff for these old motors. I trying to figure it out cause I find it challenging plus I am 21 so not many kids my age these day work on carburetors. At the Ford dealership I work at no techs know anything about carbs except one! Well I put a new accel pump cam in today with a steep lobe. It seems to have fixed the problem from what I can tell from driving up the street. So I will see if it is all good this weekend at Ocotillo. I am bringing different set ups for the carb to try out so hoping to get it all dialed in.

[[HBW]22]

Ocotillo went pretty good. The new carb set up is a lot better than it was. It needs a little more work and I think it should be fine. Found a good section of whoops for some tuning. Front end needs some valving and bypass tuning but I was happy with it. Went to go get my buddy to video tape for us and than the motor started running horrible. So I hope its not something serious I will be figuring out what's going on with it tomorrow. My buddy got one video of a jump put it was so horrible you can barely see us. So that sucks that again no video of it. Hers some pix.



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[[HBW]22]

Well motor lost all compression in cylinder 3..... Piston looked okay from what I could see. Took the valve cover off and everything seemed good there. Wet tested it with same results. Thinking it burned a valve or something like that. Pulling the head tomorrow to see,

[[HBW]22]

Well pulled the head today and found out the results. As soon as I pulled #3 cylinder rocker arm off the spring fell off. So looks like it dropped a valve and the piston hit it and bent it. Piston damage is minimal and the bore is perfect still. I think it could have been much worse, now time to fix it......




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Piston damage


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[hobbyturnedobsession]

Bent one of those before! Luckily no major damage.

[Rmc]

Looks like you got lucky.

[Ford 4 US]

CJ
What spring rates in the front ??
Thx

[cs_drums]

How hot was it out there?

[[HBW]22]

Yeah I got very lucky that's for sure. I think I can just fix the valve and run it. You guys think that would work with that minimal piston damage? And it was around 85 at night and we left by 10 in the morning and it was 95. It was nice actually, but would have been hot by noon.

[[HBW]22]

CJ
What spring rates in the front ??
Thx

250 over 300 is the spring rates front and back.

[Ford 4 US]

Thx
Have some Fox coil overs 300/750 for the front of my 79
Just wondering how they might work I know there are a ton of variables
Was just going to run the one per side
Have it mocked up right now did you use the stock lower mounts
I should figure out how to post pics

[Rmc]

750 spring rate? That's like 3/4 ton desiel weight I'd imagine, way too heavy for a bronco. As far as I know the biggest spread between a primary and secondary spring should be 100lbs.

[[HBW]22]

Thx
Have some Fox coil overs 300/750 for the front of my 79
Just wondering how they might work I know there are a ton of variables
Was just going to run the one per side
Have it mocked up right now did you use the stock lower mounts
I should figure out how to post pics

750 is way to much for a dual rate. I don't have anything stock left on the front axle now its all custom cause its 3 linked. What are you planning on doing on your front end? Extended radius arms, stock arms? This would help determine shock mounts.

Here are my lower mounts when I was making them.

[Ford 4 US]

Thx for the info...
I'll have to recheck the springs 1 is a King and the other is an elibach (sp)???
I called fox today to ask a few questions but they must have been busy
Going to send them in for svc.. If I can figure out how to put my beer down and post a few pics I will...
Thanks for the input !!!.....

[[HBW]22]

No problem man. I have a couple buddies that work at Fox what where your questions? Also I use Image shack to post pics its easy.

[Rmc]

I just ordered a new set for the front of mine and the guy was saying 250 over 300 up front, I went with lighter initial valving and a bit heavier spring and ordered 300 over 400...I think.

[[HBW]22]

I just ordered a new set for the front of mine and the guy was saying 250 over 300 up front, I went with lighter initial valving and a bit heavier spring and ordered 300 over 400...I think.

Nice man. We tried a couple different set ups on mine, but all of them had a tall ride height. 250 over 300 worked great for ride height with 7 inches of stoke left on the 14inch shocks.