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76Tahiti460
10-10-2001, 05:13 AM
I have discovered a broken valve spring (thriple spring) on my BB Chevy motor. Can I replace my springs without removing my cylinder heads? I thought I remembered articles on people placing an air fitting screwed into the sparkplug hole, and pressurizeing the cylinder so the valves will remain closed. Is this safe or feasiable? Also since I am removing the springs, is it recommended to replace the retainers and stem locks as well? Some sound (expierenced, LOL) advice would be most appreciated before I tackle this little project. The motor has no known problems that would have caused this crack. I believe it was just a fluke incident. The pressure test of each cylinder is about 122psi all cylinders being within plus or minus 1psi of each other...

superdave013
10-10-2001, 06:45 AM
Yes you can replace your springs with out removing the heads. I think my tool is made by Manley. Your retainers are most likely ok but some new locks might be a good idea. If you replace your retainers you will need to be sure that the installed height is correct.

76Tahiti460
10-10-2001, 06:52 AM
You mention "your tool"? What tool are you refering to? I have a valve spring removal tool, but I think it is used primarly for removing springs with the cylinder heads removed. Is there a tool, or something that I can improvise to remove these springs. Also since I don't know the manufacture or spring psi, is there a way I can figure out which springs to use for replacement since I don't know the type or grind of camshaft? I know the motor was built professionally. It has rect.ports, tunnel ram with 4150 conv.660 center squirters, I do know the cam is Erson (hence all the Erson Chrome Decor. all over the motor). But like I said earlier, I don't want to make a "big production" out of just wanting to simply replace the spings. What is your best logical, procedural advice for me?

HammerDown
10-10-2001, 06:58 AM
The air trick will work...sometimes.What I do is to hand feed some rope into the sparkplug hole...then by hand turn the motor so that piston comes up in the cylinder...that will stop the valve from droping.Work's fine for me. Manley valve spring compressor tool for all chevys,fords,and pontiacs with studs...part#41830.
[This message has been edited by HammerDown (edited October 10, 2001).]

76Tahiti460
10-10-2001, 07:11 AM
Great...I am taking note of that tool part#. But what about spring tension? Should I just take a collective average of spring tension psi of the current springs, and try to match those to another "New" set, with correct diameters and installed heights, etc?

HammerDown
10-10-2001, 10:55 AM
Ya answered your own question,sometimes a local speed-machine shop can help ya out.

Boater Bill
10-10-2001, 12:15 PM
Hey Tahiti, I'd make a big production out of it. Do you know who built the engine? Check with them to determine correct springs.
If not, do you know the type of cam ie solid, hyd, roller or std, this also determines what spring/spring pressure is needed. You might want to pull the timing cover and cam gear, I think cam mfgr's put a # on the snout which might help you contact the mfgr to get correct springs. You must have a healthy cam to be running triple springs. Also, I don't think checking current spring pressure will give you what you need as pressure will decrease over time due to a number of factors. Matching springs to cam is critical to performance. If you are gonna change springs, do it once and do it right. My $.02

ponponracing
10-10-2001, 07:49 PM
Make sure the piston is at TDC, Moroso has a nice tool to disassemble springs retainers and it works very good. The air in cylinder trick may work decent but if the locks are sticked in place then the valve may open slightly and you loose the air pressure. Be carefull not to drop the valve in such a case.

HammerDown
10-10-2001, 08:00 PM
As Pon. stated,dont drop the valve...that's why I like the rope trick.

lghtnin33
10-11-2001, 08:37 PM
hey 76tahiti460 sounds like you have some serious valve train load(high lift roller?)because triple springs are usually found in 9K rpm drag motors with closed pressures at 250lbs up to 950lbs open.So if you change out the springs your self you need a good QUALITY spring tool like hammerdown suggested.I would encourage checking coil bind you may need to shim. the air tool you asked about can be found at jegs,summit,PAW,etc. and most good speed shops carry them. but most important is to have the cylinder at TDC in case of pressure loss. hope you have good quality valves with fat margins because spring pressures that high can jerk the head off the valve or eventually beat the valve through the seat. good luck!

DANS66STEVENS
10-12-2001, 01:54 AM
Before you put air in the cylinder take a socket or a piece of pipe. Put it over the valve stem. Get one big enough to not contact the stem. Now take a hammer and whack the washer out side of the keeper. When you do this you will loosen the keeper and the air trick will work like a charm. WARNING....Be careful not to dislodge the keepers just a small whack should do it. If you hit it to hard the keepers will fall out and the valve will fall out. I would have it at top dead center just to be safe.GOOD LUCK!!!!!

Tinkerboater
10-28-2001, 07:27 PM
What he probably has are double springs with a flat damper between the inner and outer springs. if you broke one spring others are soon to go. sounds like its time to rebuild at least your heads.