Should I be worried?

[ryoungbronco]

When I went to break in the engine they recommended that I take the valve inner springs out. Now I'm getting ready to put them back in. I bought a tool that goes into the spark plug hole and allows you to put pressure in the cylinder to make sure the valves don't fall when doing the spring change. I have cylinder one at the point right when the intake valve has just closed, so theoretically both intake and exhaust are on the backside of the cam lobe. When I added air pressure the engine turned just a bit, I'm assuming that it has just moved the piston all the way down. I loosened the rocker arms to make sure there is no pressure on the valves but I hear a hissing sound and the #1 cylinder is not holding pressure. Should I be worried? Did I kill the valves during break in. I'm afraid to pull the springs and have a valve drop into the cylinder.

 

[Viperwolf1]

I would move the piston all the way up to TDC. That way if the valve drops it won't fall all the way into the cylinder. It's normal to have some blowby past the rings.

 

[ryoungbronco]

When I bring it to TDC won't the pressure from the air push the piston down?

 

[Justafordguy]

When I bring it to TDC won't the pressure from the air push the piston down?

I would think that it would.

 

[Justafordguy]

Can you tell where the pressure is leaking from? If it is intake or exhaust you probably have a valve problem. If it's in the crankcase I say don't worry and pull the springs.

 

[Viperwolf1]

When I bring it to TDC won't the pressure from the air push the piston down?

Not if it is all the way up. Crank journal would be inline with the centerline of the crank and there would be no rotational force.

 

[ryoungbronco]

Not if it is all the way up. Crank journal would be inline with the centerline of the crank and there would be no rotational force.

Gotcha. What about doing the valve lash? With it the way I have now I should be able to take each intake and exhaust valve out and then do the valve lash adjustment and keep going while following the firing order. I don't have the intake off to be able to see where the lifters are at.

 

[ryoungbronco]

Well here we go, keeping my fingers crossed that the valves stay in.

 

[Viperwolf1]

Gotcha. What about doing the valve lash? With it the way I have now I should be able to take each intake and exhaust valve out and then do the valve lash adjustment and keep going while following the firing order. I don't have the intake off to be able to see where the lifters are at.

Doesn't matter. At TDC after the compression stroke both valves are closed and rockers could be adjusted. It's a lot easier if your balancer is marked every 90 degrees so you know where to park the crankshaft to have the piston at the top.

 

[Oatmeal]

Old timer trick: Take some rope and feed it into the cylinder through the spark plug hole, bring that cylinder up to TDC, squashing the rope up there and keeping the valves from dropping down, bring the piston down and pull the rope out when you're done. Slow but, works good if you don't have an air compressor/air fitting dealio;D.......the thought of dropping a valve always scared me too --------Hans

 

[ryoungbronco]

Made it through two cylinders and had to stop for the day. It took me more time to get the fitting into the spark plug hole and then hook up the air compressor line than it did to pull each spring off and put it back on. Damn, headers!

 

[Skiddy]

When I went to break in the engine they recommended that I take the valve inner springs out.

never heard of this before can someone explain?:?

 

[JWMcCrary]

never heard of this before can someone explain?:?

That's because you are a "Bronco Newbie" ;D

X2, I haven't heard before now either.

 

[Skiddy]

That's because you are a "Bronco Newbie" ;D

X2, I haven't heard before now either.

dangit that's what i thought, but i can see yer welds;D

 

[Hauq]

Most procedures recommend that you take out the inner springs when breaking in the cam. I thought it was unnecessary and destroyed a cam. I won’t do that again. Education always costs.

 

[pcf_mark]

Yeah what he said. Ground up a perfectly good cam that way too.

It is odd however to have a cam with dual springs in a Bronco. You usually need that for higher rpm work.

Your hands get tired cranking on the valve spring compressor but I sweat more worried about a valve dropping too!

 

[ryoungbronco]

Many people told me not to pull the inner springs but I read many posts of how people wiped the lobes on there cam during break inbecause they didn't listen to the manufacturers directions. I didn't want metal shards destroying the motor. Most manufacturers recommend the removal of the inner spring for hydraulic lifters like mine.

The heads are AFR's and came with the dual spring setup.

 

[Nightstick]

I thought you had a roller? The way I understand it is you don't have to worry so much about spring pressure with the rollers, just the flat-tappet. Have you checked the spring pressure on those springs that came with the AFRs as opposed what the cam recommendations are? My TFS sprigs were upwards of 420lb open so I swapped them to a MUCH lighter spring.

 

[ryoungbronco]

I thought you had a roller? The way I understand it is you don't have to worry so much about spring pressure with the rollers, just the flat-tappet. Have you checked the spring pressure on those springs that came with the AFRs as opposed what the cam recommendations are? My TFS sprigs were upwards of 420lb open so I swapped them to a MUCH lighter spring.

No it is a hydraulic flat tappet. That is why I took the extra time to take out the inner springs. They are rated at 360. Too high? I can't find any info for the cam and what spring rate they recommend.

 

[Nightstick]

Hmm, what cam are you using? Compcams has all their info available. It doesn't say "we recommend this spring pressure", instead is as suggested parts which includes springs. The highest mine recommended was in the area of 300 so that's what I went with.

I also emailed compcams back and forth a few times asking their tech guys what to use.