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Hello, first of all I am working on a sbc 350 with vortec heads, dished four valve relief pistons. Comp xe268 cam .477 .480 lift, 1.5 roller tip rockers on intake and 1.6 on exhaust. After I put the motor together and installed it in my car I tried to start it. After a few minuets of messing with timing, trying to get it to start I noticed gas pouring out my exhaust. After that, I discovered that I needed a fuel pressure regulator. After I installed one I tried to start it again. With no luck I pulled the valve covers and found most of my push rods bent. I'm trying to figure out how they bent and how to prevent it from happening again. Bty the motor never ran. It was just the starter turning the motor. Is it possible I have a bent valve. Could have my piston slapped a valve?
 

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A long for the ride on this one to see what did it...

Cam installed incorrectly?

CNC Blocks, I thought the exhaust was inefficient that is why 1.6 on exhaust side as a common practice.

Coil bind because the Vortex heads have a poor coil spring for more than stock cams? 477/480 lift don't sound like much...

And I'll be the first to admit that I have a lot to learn with engine building...

Mark
 

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Could be any one of the situations mentioned, from coil bind to push rod length. But I too have to ask, didn't you roll the engine over after building it and/or prior to firing it up??? :confused:

Sometimes the simplest things save you the most time, aggravation and money.
 

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IMHO!

First, were the Vortec head valve guides modified for a more lift?

If not!

First, you could have had the lifter pre-load incorrectly adjusted, meaning too tight.

This would cause (not coil bind) but guide/retainer intrusion, Limiting lift.

Were the bent push rods only on the exhaust side? The standard formula is Vortec heads the lift limit without modification to the guides, is limited to .500 (some have found heads that are limited to .460) with your 1.6 rockers your lift now on the exhaust side is over that limit. At 1.5 the lift is .480 at 1.6 the lift is .512

THE VALVE GUIDE/RETAINER INTRUSION MUST BE CHECKED!


A compression check will tell if you bent a valve. I honestly believe you have not and your problem is Valve guide/ retainer intrusion.

Al

 

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A long for the ride on this one to see what did it...

Cam installed incorrectly?

CNC Blocks, I thought the exhaust was inefficient that is why 1.6 on exhaust side as a common practice.

Coil bind because the Vortex heads have a poor coil spring for more than stock cams? 477/480 lift don't sound like much...

And I'll be the first to admit that I have a lot to learn with engine building...

Mark
On the dyno I have not seen much of a gain if any just by adding 1.6 to the exhaust now on the intake I have seen a gain.
 

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A compression test won't be very accurate with bent pushrods. I would do a leak down test to see if the motor is still sound. What was the fuel pressure at. With fuel running out the exhaust ports you may have hydro locked this motor. Is the cam timing correct? RICK
 

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I'm with Big Al on this one!!

Sounds to me like either you found coil bind or a retainer found the valve stem seal.:yes:

It's a fairly common issue with Vortec heads. The guides need to be cut down and either the spring pockets cut or longer valves used to increase your "Installed Height".

THEN and only THEN can you run over .500" lift without worrying about interference issues.
 

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A compression test won't be very accurate with bent pushrods. I would do a leak down test to see if the motor is still sound. What was the fuel pressure at. With fuel running out the exhaust ports you may have hydro locked this motor. Is the cam timing correct? RICK
You remove the push-rods and do compression check. Leak down would be the preferred test.

Al
 

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IMHO!

First, were the Vortec head valve guides modified for a more lift?

If not!

First, you could have had the lifter pre-load incorrectly adjusted, meaning too tight.

This would cause (not coil bind) but guide/retainer intrusion, Limiting lift.

Were the bent push rods only on the exhaust side? The standard formula is Vortec heads the lift limit without modification to the guides, is limited to .500 (some have found heads that are limited to .460) with your 1.6 rockers your lift now on the exhaust side is over that limit. At 1.5 the lift is .480 at 1.6 the lift is .512

THE VALVE GUIDE/RETAINER INTRUSION MUST BE CHECKED!


A compression check will tell if you bent a valve. I honestly believe you have not and your problem is Valve guide/ retainer intrusion.

Al

Nailed it!!!!!!!!!:yes::yes::yes:
 

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You remove the push-rods and do compression check. Leak down would be the preferred test.

Al
I sure would like to know what the fuel pressure was. FUEL RUNNING OUT THE EXHAUST PORTS BOTHERS ME AS TO HOW MUCH DAMAGED WAS CAUSED. I HAVE NEVER BUILT A MOTOR THAT WASN'T TURNED OVER BY HAND BEFORE I RAN IT. IT'S GOING TO BE A VERY EXPENSIVE LESSON LEARED. RICK
 

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I sure would like to know what the fuel pressure was. FUEL RUNNING OUT THE EXHAUST PORTS BOTHERS ME AS TO HOW MUCH DAMAGED WAS CAUSED. I HAVE NEVER BUILT A MOTOR THAT WASN'T TURNED OVER BY HAND BEFORE I RAN IT. IT'S GOING TO BE A VERY EXPENSIVE LESSON LEARED. RICK
On a hyd. cam shaft engine that will tell you to much as the lifter will not be pumped up. Once the engine is running its a different story.

With that small of cam P/V clearance should not be an issue unless the cam was not installed correctly.
 

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On a hyd. cam shaft engine that will tell you to much as the lifter will not be pumped up. Once the engine is running its a different story.

With that small of cam P/V clearance should not be an issue unless the cam was not installed correctly.
You're right. I guess for me turning the engine is just habit. I used to do alot of diesel and multi overhead cam motors. Getting to old to change now. You know what they say you can't teach a old dog new tricks. RICK
 

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Don't forget to change that oil or you will be replacing rod bearings, mains, and rings.:yes:
 
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