Engine 85 Fox 5.0 Rebuild Has Less Power

[Justin85fox]

HELP HELP!!
I have just rebuilt my factory roller motor carbed 85 fox 5.0. I put new gt40 heads on with the springs, valves, etc that comp cams recommended. I put factory bore pistons, rings, and new eldebrock 650 carb with eldebrock intake. The cam is a comp cam magnum series 35-440-8. On first fire up the car ran and idled fine. I broke in the motor as recommended.
On first drive it did not have much power and bogged down when given much gas. The car idled down and died. I checked the timing and it was a few degrees off. After advancing the timing a few degrees it is hard to start and lost even more power and the temp raised close to overheading. It is drivable but much less power than stock.. From all I know it sounds like a timing issue, but it shows to be perfect. Compression is within range. What is wrong? Any help is appreciated. Thanks.

 

[Lscam580]

Ok for the sake of just asking did you put new Pistons on the rods? If yes was this task preformed by you or a shop? I'd first try putting the motor at tdc pull the distributor cap and see if it lands before the number one spark tab or after. It could very well be a tooth off. with that cam did it call for a stock length pushrods or a different size? Was the carb tuned properly? And for the first part, of my question reasons being if new Pistons were installed did they put the piston the right way on the rod. is the rod backwards on the crank. Which can give a horrible loss in power, binding at the crankshaft loss of power.

 

[Justin85fox]

I had the shop put new pistons and everything in except for the carb, radiator, alternator, etc. I believe the push rods fThey have assured me all they did is correct and it should "scream" once I tune it correctly.

 

[Justin85fox]

My previous post left a sentence off. I believe the push rods of factory spec were used, but they did all of that. I am just finishing it to save $$$$

 

[84Ttop]

Do you have your old carb? In my past experience the Edelbrock carbs are junk, I would try your orig. carb first if you still have it on hand. This is assuming of course that it ran fine with no issues beforehand

 

[Justin85fox]

I hope it's not junk! It was not cheap.haha. I do have the factory carb, but it leaks. If it comes to it I can put it back on to test. I am not an expert by any means, but I would hope a new eldebrock 650 would give it enough fuel. Do you think the new carb could be bad?

 

[Lscam580]

The cam card shows if using a auto use a stall converter, if stick your good there, so the shop built the long block you just finish it off with a fuel kit intake carb plumbing, then it's back to carb or timing. Make sure you don't have a dead vac leak either. I hate hate hate edelbrock carbs. Bought a brand new edelbrock off the shelf installed it and ran horrible on new motor, same day went out bought a demon slapped it on there and omg that car was a monster that I almost couldn't control. From that point on I spit on junk edelbrock carbs

 

[Lscam580]

For $120 more go buy yourself a quick fuel carb or Holley or a demon carb.

 

[Justin85fox]

The cam card shows if using a auto use a stall converter, if stick your good there, so the shop built the long block you just finish it off with a fuel kit intake carb plumbing, then it's back to carb or timing. Make sure you don't have a dead vac leak either. I hate hate hate edelbrock carbs. Bought a brand new edelbrock off the shelf installed it and ran horrible on new motor, same day went out bought a demon slapped it on there and omg that car was a monster that I almost couldn't control. From that point on I spit on junk edelbrock carbs

Yes, it is a 5 speed manual. and yes the shop built the long block and I have done the rest. I hope is it just a simple carb or timing i can change without taking the motor down. I believe it to be timing, but it shows to be good. I will have to keep tinkering and try to not be frustrated.

 

[Lscam580]

What distributor are you running? When you pulled the distributor cap was the rotor button before or after the #1 cylinder? What is your base timing and total timing?

 

[Lscam580]

This is my email address. Email me and I'll send you over my cell number and I can pretty much walk you through a few things. [email protected]