Stock valve springs on a big block....

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dkbug

dkbug

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Please correct me if I am wrong, but stock valve springs weren't painted the same color as the clock were they? Not just the painted line saying they were checked, but the whole valve spring was painted. Just curious if what I have are stock springs or not.

Thanks in advance from the pro's at FABO,

Dakota
 
Hmmmmmmmmm then I don't have stock springs. I'm gonna run these babies to the machine shop tomorrow to have them check spring pressure tomorrow!! Hopefully these guys are ready to be bolted on and ran!!


Dakota
 
Might see if they can tell you the bind height as well, may come in handy.
 
All factory High Performance big block, 383 and 440, and small block, 340 and 360, valvesprings were painted red all over, except for the damper. Never coil bind a spring, you will weaken it.
 

.........do ur pistons have valve reliefs in them.......usually need to cut the guide down with lifts over .510............kim........
 
No valve relief on the pistons. Would it hurt to mill down the guides regardless if it needs it or not? I wouldn't imagine but I figured I would ask.

Dakota
 
I would ck the valve to piston clearance with some clay. I ck without a gasket and want .080 on the intake and .090-.100 on he exhaust. Once you get your figures you can add the compressed head gasket to the figures you get and know how much clearance you do have.
Retainer to guide clearance should be .090.
 
SGBARRACUDA said:
I would ck the valve to piston clearance with some clay. I ck without a gasket and want .080 on the intake and .090-.100 on he exhaust. Once you get your figures you can add the compressed head gasket to the figures you get and know how much clearance you do have.
Retainer to guide clearance should be .090.
Click to expand...

Ok I checked clearance. I got .104 on the intake side with a head gasket. Didn't hit the clay on the exhaust. Now I am zero decked with stock valves so I have to take that into play.. I didn't get time to check retainer to guide height. Will be checking tomorrow. Tips on measuring this?

Any tips on measuring spring tension?

What I am planning on doing is I am going to hook up my rockers and get everything ready to measure when I go to check spring binding. I'm going to go down the line and make sure that I have .050" between coils on the spring at fully compressed height. Installed height is all correct according to the diagram I got with the springs, so I am good there.

Thanks for the help in advance,

Dakota
 
Also, school me on floating valves. I was told by an edelbrock tech that with my setup and a .526 cam, I would be in danger of floating a valve at 5k+ rpm. (Offered to sell me different springs, so maybe he was just trying to sell me something?) I am running a dual plane intake so I am hoping to be more in the middle as far as peak torque and horsepower go, so this motor won't ever see 6k, I hope.

Thoughts and opinions?

Keep in mind, I am on a very tight budget on this build and have everything I need to put the motor in the car minus a bellhousing and A-body 4 speed linkages IF I can run these springs.


Dakota
 
They will have very low seat pressure at installed height. Specs are 120lbs at 1.73". Seems light for a MP .526 cam. Lots of lift for short duration on that mech cam. Float will happen if you don't run a spring with enough pressure to control valve movement.
 
Well the right way to ck retainer to guide clearance is with a solid lifter. Install the rockers on at least one cylinder, adjust the rockers to zero clearance then turn the engine over to max lift/valve open, check clearance between bottom of the retainer and the top of the guide. If you have plenty of clearance, then when you adjust the valves to the recommended clearance you will have that much more clearance. Your looking for at least .090.
 
Here are the specs from the edelbrock website.

383-400-413-440 V8 '69-79

part # 5992

120 lbs

1.390" OD/1.020" ID

1.730" Installed height.

So lets get this straight, the cam was advertised at .508/292 and ACTUAL lift is .328. Duration i'm not sure of.

The paper the springs came with said that .050" was a good measurement between springs coils when compressed. (thoughts?) More or less?

Any pros good at figuring out what RPM I will have to hit to risk floating a valve? I am taking some high level engineering classes but haven't quite hit the level to have the knowledge to figure that one out.

Definitely one of the most fun things I have ever done is tackle building this motor myself WITHOUT a machine shop/

Thanks, Dakota
 
Installed height on a BB is 1.86". Higher if you've had valve work done. This means your seat pressure will be even lower than the advertised 120#. Do you know the spring rate or open pressure? Is yor cam the 528 mechanical purple shaft? 284/284 duration?

Basically that spring is recommended for a hydraulic cam with Chevy lift rates. If you were running a hydraulic purple shaft I'd say it would be ok. Unless that is what you have as the original cam was stated as 528, your last post states 508/292. So do you actually have the hydraulic .509 cam with 292 duration?
 
I do not know the spring rate or open pressure. I was asking in an earlier post if there was a way of measuring it without taking it to a machine shop.

It's definitely a flat tappet cam. The actual lift on the cam is .328 at the lobe and I am running stock rockers, so whether or not it's the .508 or .528, it's beyond me seeing as how I am not the one who purchased or installed the cam. The guy I bought the motor from states that it's the .508.

The valves are stock. The only spring Edelbrock offers that is 1.86" is the same spring as mine but a non-rotator.
 
If actual measured lift at the lobe is .328, multiply it by 1.5 to get lift at the valve. So .492 lift at valve. Is there, or has there been a .492 lift purple shaft? I honestly do not know. But if you do have a MP Hydraulic flat tappet cam, with a lift between 492 and 509, i would think that in a pinch those springs would work. Maybe even work great. Just not enough information available here. If it is a mechanical flat tappet I wouldn't. If it is an comp XE, voodoo, or hughes hydraulic, I wouldn't.
 
Well tomorrow I am going to attempt to get out in the garage and do some more clearance measurements. I am failing to see how I am going to measure between the retainer and guide though, especially when compressed. I was thinking about painting the valve shaft or something like that so when compressed at full lift, it would rub the paint off and I could measure the valve out of the head? Possibly an easier way?

Can't thank you guys enough for helping out a newbie. Gotta love a young'n lovin' the best cars out there though!!!

Dakota
 
SGBARRACUDA said:
Well the right way to ck retainer to guide clearance is with a solid lifter. Install the rockers on at least one cylinder, adjust the rockers to zero clearance then turn the engine over to max lift/valve open, check clearance between bottom of the retainer and the top of the guide. If you have plenty of clearance, then when you adjust the valves to the recommended clearance you will have that much more clearance. Your looking for at least .090.
Click to expand...

Alright you got the cogs in my head turnin'. HOW ABOUT THIS?.... If I have .104" clearance from the valve to the piston at max lift and TDC, can't I find out my retainer to guide clearance that way? I'm sure a pencil, good eraser along with a calculator and a piece of paper could figure this one out with enough bare measurements.

Dakota
 
Oh duh. Good point. Well ill try to put some kind of paint on the valve shaft and let it run off going intl the guide and ill measure what's left for clearance. I think that would be easiest right?
 
Fully compressed I have less than .060" between the coils on my springs. What to do now.. Go with different springs, or have a machine shop machine the plate where the spring sits on the head..?
 
Do it right. Get the right springs. What cam is it?
 
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