Setting spring height? What the #&@$ is that all about?

2FastLX · 03-30-2001, 12:08 PM

I have been screwing around with this guy at the machine shop trying to get my heads back for 2 weeks now. All he has left to do is lap the valves (I thought), but he said he also has to set the spring height. What is that all about?

I have adjustable rockers and Crane springs setup for an F303.

What is he talking about and how do you do it if I actually need to have it done because I am getting the heads back tonight so I can get my car back together. He's not going to have the damn things done until Monday and I can't wait that long.

I have indicators, calipers, mics, and any other precision tool you can think of so if this guy can do it so can I. Please, help me out guys. The car's going back together tomorrow I hope.

------------------
ICQ# 42269241
Indiana Stangers Association
Buy your parts here

2FastLX · 03-30-2001, 12:35 PM

Nevermind. I guess he is going to have that part of the job done tonight for me. Whew!

I'm still kinda curious though as tho how you do this.

------------------
ICQ# 42269241
Indiana Stangers Association
Buy your parts here

Jeff Chambers · 03-30-2001, 01:09 PM

Setting the spring height is the MOST critical portion of setting the valves up IMHO. You need a certain seat load with the springs and a certain 'open' load. Too much open load and you're wasting HP. Too little and the valve won't have enough load in it to keep the lifter following the lobe. Same with the seat load, too little and the valve may bounce off the seat; too much and you may damage the valve seat. Most cams come with a recommended spring load. Since the springs you've bought will fit many different heads, the springs have to be shimmed to achieve the spring loads recommended for the cam.

Have patience. It'll be worth it in the end.

BTW: The Comp Cams catalog has a wealth of information dealing with all aspects of the valve train. Real good reading. I'd suggest that everyone have a copy.

------------------
Jeff Chambers
Trophy Stock #3
11.86 Seconds / 113.8 MPH
Chambers Racing Team

2FastLX · 03-30-2001, 02:04 PM

Anyone happen to know the recommended spring pressure for an F303? It didn't say anything about that on the spec card or anywhere on the box. Or maybe a phone number for Ford Racing?

I've tried to get on Ford Racing's web site but it keeps locking my pc up =(

------------------
ICQ# 42269241
Indiana Stangers Association
Buy your parts here

Chevyguy · 03-30-2001, 02:04 PM

Another critical issue with installed height is the total lift available. If you use the wrong installed height the valves may not be able to open as much as the cam manufacturer intended. This can cause coil bind, and broken valve springs, bent pushrods etc. Part of your spring specs will list a maximum lift value. Make sure you dont exceed this value especially when going from 1.6 to 1.7 ratio rockers. A cam at 0.50" lift at 1.6:1 rocker ratio will have 0.5313" lift with 1.7" rockers. If the springs only had 0.525" max lift you will have problems.

------------------
Frank W
90 5.0 LX coupe Daily driver. Silencer removed, K&N filter. Flexalite fan, 3 core radiator. FMS flywheel and Clutch Finally rebuilt T-5.

74 Chevy Laguna Type S-3 305 apart in garage, getting a 454 to put next to it
www.chevellepages.com/folingo

2FastLX · 03-31-2001, 12:18 AM

I'm almost ready to cry or go kill someone (slight exaggeration here) because now I guess my springs aren't coming out at the right height.

The machine shop dude said that the stock springs use a rotater (?) and the Crane springs do not. This is causing problems and the exhaust springs are .060 too short and the intake springs are .180 too tall! Am I being fed a line of chit or what? You would think that if you bought a set of springs for a set of stock heads they would work with stock valves.

Can someone please tell me this guy is jerking me off and I need to take these heads to another shop! I'll have to wait another week now and I'm pulling my hair out now as it is.

I should have just bought a new engine and been done with it all.

Sob.

------------------
ICQ# 42269241
Indiana Stangers Association
Buy your parts here

Oldschoolpony · 03-31-2001, 02:22 AM

^2fastlx^ : ) you need to contact the spring and cam manufacturer and ask them these qustions. Its quite possible that you need some extra hardware to set up these springs. Also, your machinist should be able to solve this problem without a problem.

2FastLX · 03-31-2001, 02:43 AM

It turns out I was sent the wrong springs and retainers. The shop guy's gonna love this one.

That's the first time I've ordered anything for my car without asking here first if I was making a good decision. I was told these were the correct springs so it's not totally my fault, but I should have researched this a bit more. If I had, I'd be driving my Stang by Sunday =(

I miss my car so much, and I think it's going to be so mean after all these parts get installed and I can't wait to take it on a hell run. It's driving me nuts!

------------------
ICQ# 42269241
Indiana Stangers Association
Buy your parts here

03-30-2001, 12:08 PM	#1
2FastLX The Photoshop Guru Join Date: Feb 2001 Location: Mecca, Indiana Posts: 1,419	Setting spring height? What the #&@$ is that all about? I have been screwing around with this guy at the machine shop trying to get my heads back for 2 weeks now. All he has left to do is lap the valves (I thought), but he said he also has to set the spring height. What is that all about? I have adjustable rockers and Crane springs setup for an F303. What is he talking about and how do you do it if I actually need to have it done because I am getting the heads back tonight so I can get my car back together. He's not going to have the damn things done until Monday and I can't wait that long. I have indicators, calipers, mics, and any other precision tool you can think of so if this guy can do it so can I. Please, help me out guys. The car's going back together tomorrow I hope. ------------------ ICQ# 42269241 Indiana Stangers Association Buy your parts here

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03-30-2001, 12:35 PM	#2
2FastLX The Photoshop Guru Join Date: Feb 2001 Location: Mecca, Indiana Posts: 1,419	Nevermind. I guess he is going to have that part of the job done tonight for me. Whew! I'm still kinda curious though as tho how you do this. ------------------ ICQ# 42269241 Indiana Stangers Association Buy your parts here

03-30-2001, 01:09 PM	#3
Jeff Chambers Moderator Join Date: Aug 2000 Location: Milan, OH Posts: 2,699	Setting the spring height is the MOST critical portion of setting the valves up IMHO. You need a certain seat load with the springs and a certain 'open' load. Too much open load and you're wasting HP. Too little and the valve won't have enough load in it to keep the lifter following the lobe. Same with the seat load, too little and the valve may bounce off the seat; too much and you may damage the valve seat. Most cams come with a recommended spring load. Since the springs you've bought will fit many different heads, the springs have to be shimmed to achieve the spring loads recommended for the cam. Have patience. It'll be worth it in the end. BTW: The Comp Cams catalog has a wealth of information dealing with all aspects of the valve train. Real good reading. I'd suggest that everyone have a copy. ------------------ Jeff Chambers Trophy Stock #3 11.86 Seconds / 113.8 MPH Chambers Racing Team

03-30-2001, 02:04 PM	#4
2FastLX The Photoshop Guru Join Date: Feb 2001 Location: Mecca, Indiana Posts: 1,419	Anyone happen to know the recommended spring pressure for an F303? It didn't say anything about that on the spec card or anywhere on the box. Or maybe a phone number for Ford Racing? I've tried to get on Ford Racing's web site but it keeps locking my pc up =( ------------------ ICQ# 42269241 Indiana Stangers Association Buy your parts here

03-30-2001, 02:04 PM	#5
Chevyguy Backyard Mechanic/Chemist Join Date: Feb 2001 Location: Acton MA USA Posts: 435	Another critical issue with installed height is the total lift available. If you use the wrong installed height the valves may not be able to open as much as the cam manufacturer intended. This can cause coil bind, and broken valve springs, bent pushrods etc. Part of your spring specs will list a maximum lift value. Make sure you dont exceed this value especially when going from 1.6 to 1.7 ratio rockers. A cam at 0.50" lift at 1.6:1 rocker ratio will have 0.5313" lift with 1.7" rockers. If the springs only had 0.525" max lift you will have problems. ------------------ Frank W 90 5.0 LX coupe Daily driver. Silencer removed, K&N filter. Flexalite fan, 3 core radiator. FMS flywheel and Clutch Finally rebuilt T-5. 74 Chevy Laguna Type S-3 305 apart in garage, getting a 454 to put next to it www.chevellepages.com/folingo

03-31-2001, 12:18 AM	#6
2FastLX The Photoshop Guru Join Date: Feb 2001 Location: Mecca, Indiana Posts: 1,419	I'm almost ready to cry or go kill someone (slight exaggeration here) because now I guess my springs aren't coming out at the right height. The machine shop dude said that the stock springs use a rotater (?) and the Crane springs do not. This is causing problems and the exhaust springs are .060 too short and the intake springs are .180 too tall! Am I being fed a line of chit or what? You would think that if you bought a set of springs for a set of stock heads they would work with stock valves. Can someone please tell me this guy is jerking me off and I need to take these heads to another shop! I'll have to wait another week now and I'm pulling my hair out now as it is. I should have just bought a new engine and been done with it all. Sob. ------------------ ICQ# 42269241 Indiana Stangers Association Buy your parts here

03-31-2001, 02:22 AM	#7
Oldschoolpony Registered Member Join Date: Mar 2001 Location: Gainsville,Fl Posts: 229	^2fastlx^ : ) you need to contact the spring and cam manufacturer and ask them these qustions. Its quite possible that you need some extra hardware to set up these springs. Also, your machinist should be able to solve this problem without a problem.

03-31-2001, 02:43 AM	#8
2FastLX The Photoshop Guru Join Date: Feb 2001 Location: Mecca, Indiana Posts: 1,419	It turns out I was sent the wrong springs and retainers. The shop guy's gonna love this one. That's the first time I've ordered anything for my car without asking here first if I was making a good decision. I was told these were the correct springs so it's not totally my fault, but I should have researched this a bit more. If I had, I'd be driving my Stang by Sunday =( I miss my car so much, and I think it's going to be so mean after all these parts get installed and I can't wait to take it on a hell run. It's driving me nuts! ------------------ ICQ# 42269241 Indiana Stangers Association Buy your parts here