Cam install troubles.

[jerrad]

Guys,
I installed a roller cam a while back and the car ran like crap and popped under load. I pulled the pushrods out and they were 8.050. I called the person I got the cam from and they said I should have 8.200's in there. I bought the 8.200's and installed them about 30 minutes ago and now the car wont start. It sounds like the valves are staying open 100% of the time.

When I crank the car it spins very fast and thats it. Does it seem like my pushrods are now too long and not letting the valves close fully?
Thanks for any help.

 

[turbo nasty]

Did you use a adj pushrod on initial setup for proper valve tip geom and lifter preload to get the proper size pushrod?

Every car is different due to machining, gaskets, gasket squish, decking ,etc.

 

[bison]

Guys,
I installed a roller cam a while back and the car ran like crap and popped under load. I pulled the pushrods out and they were 8.050. I called the person I got the cam from and they said I should have 8.200's in there. I bought the 8.200's and installed them about 30 minutes ago and now the car wont start. It sounds like the valves are staying open 100% of the time.

When I crank the car it spins very fast and thats it. Does it seem like my pushrods are now too long and not letting the valves close fully?
Thanks for any help.

Why would you buy anything without checking to get the correct length?

 

[Mad_Trbo]

Guys,
I installed a roller cam a while back and the car ran like crap and popped under load. I pulled the pushrods out and they were 8.050. I called the person I got the cam from and they said I should have 8.200's in there. I bought the 8.200's and installed them about 30 minutes ago and now the car wont start. It sounds like the valves are staying open 100% of the time.

When I crank the car it spins very fast and thats it. Does it seem like my pushrods are now too long and not letting the valves close fully?
Thanks for any help.

You can answer your own question if you like and do a leakdown test. But like the other members said you should definitely check for proper geometry with an adjustable pushrod tool. It does sound kind of like things are hanging open. I would be careful this is one thing you want to avoid as piston to valve contact can be troublesome.

Good luck

 

[bison]

You can answer your own question if you like and do a leakdown test. But like the other members said you should definitely check for proper geometry with an adjustable pushrod tool. It does sound kind of like things are hanging open. I would be careful this is one thing you want to avoid as piston to valve contact can be troublesome.

Good luck

Using a pushrod checker will not correct a geometry problem. If the geomety is off he will need to raise or lower the rocker arms.

 

[87buickracer]

Guys,
I installed a roller cam a while back and the car ran like crap and popped under load. I pulled the pushrods out and they were 8.050. I called the person I got the cam from and they said I should have 8.200's in there. I bought the 8.200's and installed them about 30 minutes ago and now the car wont start. It sounds like the valves are staying open 100% of the time.

When I crank the car it spins very fast and thats it. Does it seem like my pushrods are now too long and not letting the valves close fully?
Thanks for any help.

make sure your degree the cam.If the cam is 180* out it will pop under load and run like crap..and valves won't open and close properly.you won't have compression in some of the cylinders and that's what it will sound like..

 

[bison]

make sure your degree the cam.If the cam is 180* out it will pop under load and run like crap..and valves won't open and close properly.you won't have compression in some of the cylinders and that's what it will sound like..

Lol. It will fire through the intake

 

[87buickracer]

Lol. It will fire through the intake

BIG BACKFIRE----BOOM!!!:biggrin:

 

[jerrad]

Thanks for all the help guys. Looks like I'll get a checker and figure out the proper length. Does the motor need to be a tdc when I do this or can it be anywhere?
Thanks

 

[machinegun]

Checking pushrod length is a time consuming proposition.

When ever I build a customers engine, I always measure every intake and exhaust. It ensures that you get the proper preload on all lifters.

I recommend doing the intake and exhaust on all cylinders.

 

[jerrad]

Thanks for the tip. Do you notice alot of varience?

 

[DR BOOST]

make sure your degree the cam.If the cam is 180* out it will pop under load and run like crap..and valves won't open and close properly.you won't have compression in some of the cylinders and that's what it will sound like..

how do you put a cam 180 deg out?

 

[yullose]

I assume you don't have an adjustable valvetrain...

Adjustable roller rockers are worth their weight in gold.

 

[jerrad]

I'd like to get some but I don't want to throw money at it and it not fix anything.

Does anyone know if having the wrong length pushrod would cause the popping?

 

[bison]

I'd like to get some but I don't want to throw money at it and it not fix anything.

Does anyone know if having the wrong length pushrod would cause the popping?

yes

 

[HouseofSpeed]

how do you put a cam 180 deg out?

Pretty easy to do...always a good idea to put a wheel on one and verify TDC compression in relation to sprocket position.

 

[jerrad]

Thank you sir. I'm going to dive into it tomorrow am and see if I can fix this turd.

 

[jerrad]

I'm about to measure the pushrod length and have a quick question. Does intake/exhaust valve need to be in any particular spot before I measure or does it matter?
Thanks

 

[DailyDrifter]

I believe it should be on base circle.

 

[jerrad]

How do you get there? I turned the motor until the intake valve just started to open and measured at that point.

Also, the pushrods that I installed first have about 15 miles on them and the ends are already bare metal. Does that sound like they're too long?