I just recieved my heads today and they are a thing of beauty. My only complaints if they would have cleaned the heads of all the metal shaving before shipping, but that to easy to fix. ;)
Now I finally got the correct valve spring specification and need some opinion before I install the heads.
My cam is the UDHarold 280/284F10
247/251@.050, .525/530 Lift 110 LSA 106 center.
Here is the specs on AFR Springs:
Part# 8016
Size: 1.550 OD
.750 ID
Pressure 140# @ 1.930
365# @ 1.380
Coil Bind: 1.140

Rate: 410
Lift 600

Will these spring work without damaging my Solid Cam.
Since Lunati grind the cam with 4* and Harold recommend that you install it with 4-6 degree's will it be fair to say that on my timing set (Cloyes 3100) I can move it 2* advance to get the extra low end torque. :confused:
In hindsight I might not need the extra torque down low with this SBC 400 and probable be better retarding the cam 2* for the top end. graemlins/thumbsup.gif What do ya'll think about this for a 95% street cruiser.
Thanks in Advance
David

I went and flipped my freshly dusted, multi-angle valve job alum head over to put on the block for some checking, glitter man, all sorts of glitter, in my fresh mill. Piece by piece it came out back out. redface.gif

At least you caught it first!

OK, just wanted to say don't mess with the cam phasing unless you run into p/v/ clearance issues ( other than the glitter I got when I checked mine!)stab it in + 6 if thats what the cam card says to do. You won't miss ANY high end - trust me. And also be sure to run the cam in on outers only. Those pressures sound quite high.

DEEBOO,

Make SURE you break the cam in with outer ONLY. No small block Chevy needs to be broken in with 365 lbs open. I don't even like 330 lbs open.

Do not retard the cam for more top-end. You will lose top-end, mid-range, and bottom-end. Running it 4 to 6 degrees advanced will give you the best overall power band, including top-end. I have had a number of cams make their best top-end 7° advanced, including some rollers I did for Pontiac Motor Company.

UDHarold

Originally posted by UDHarold:
DEEBOO,
Make SURE you break the cam in with outer ONLY. No small block Chevy needs to be broken in with 365 lbs open. I don't even like 330 lbs open.
UDHarold Would you recommend that I change the springs out for something lighter than what AFR put on the heads. I really dont want to wipe a lobe or cause undue stress that the cam don't need. I would rather fix it now rather than later.

I hope Harold chimes back in, but yes, that seems heavy to me, not something you'd want to spend any time idling with, and it is a street car, right? I'd surf www.competitionproducts.com (http://www.competitionproducts.com) and see what they have, alot of GM take out stuff cheap. EG, the zz350 take outs seat at 110, with around 315 on the nose. Spot on street spring.

Personally, I've seen a lot of springs be WAY off from advertised specs, usually they are HIGHER. I will never run springs again in any engine unless I check at least one but I'll personally check all.

I would have someone check the rate on 1 spring before I'd make a decision. Should take 2 minutes if someone has a std spring tester.

As said, they seem too high for a flat tappet cam and you are smart to want to avoid problems.

If you go with a different spring, I would like to buy your old ones.

this is a great topic. I also have a set of AFR210cc heads waiting to go on my blown SB355. I'm currently awaiting my UD276/284F12 solid cam. I think I have the same springs as you do. So, if you do decide to change them out I would also like to look into doing the same as to avoid problems in the future. Thanks

I will not commit to installing these springs until I'm 100% sure they will not wipe my cam.
The heads look awesome and the cnc and polishing is great, but im not to fond on the spring pressure.

Originally posted by STEVO-70:
this is a great topic. I also have a set of AFR210cc heads waiting to go on my blown SB355. I'm currently awaiting my UD276/284F12 solid cam. I think I have the same springs as you do. So, if you do decide to change them out I would also like to look into doing the same as to avoid problems in the future. Thanks STEVO
Here is what I plan to do after brainstorming all weekend long with the AFR spring and the possible long term effect it will have on my cam and lifters. I went to Lunati home page and found the springs that they recommend for that cam, which is 125 open and 325 seat. So I do not like idea of premature wear of the cam using the AFR springs. I feel that it's best to change the spring to match the manfacture recommendation. Yes it will cost you more now, but the long time results of less valve train wear will offset this initial cost.
Cody, you might want to look into this also....
Here is the Lunati Springs for your cam:
Lunati Springs Part # 73100
OD: 1.45
ID: 0.73
Seat Load: Height= 1.85 Load= 125
Open Load: Height= 1.25 Load= 325
Coil Bind: 1.11
Max Lift: 0.68
Rate: 333
Retainer part# 75702

The Lunati's springs end up with about 295 pounds of open pressure, which is perfect for longer cam life. Our cam will survive with high quality oil and the AFR springs (you could even remove some shims to lower the seat and open pressures, maybe as low as 340 open) however your cam and lifter life will be greatly shortened compared to the spring weights intended for that cam, even with proper break in procedures.
I will spend the money to buy the correct springs.
Springs $87.00
Retainer $48.00
Total:$135.00
Deeboo graemlins/hurray.gif

DEEBOO, with your cam you have about .510 net lift. .530 - .020 lash. The open pressure of your current springs at 1.93 installed is 349 lbs. If you can install them at 1.95, you will have 132/341 seat/open pressure with your cam. I don't think there is any need for you to change springs. You can install them higher if you have room. Don't remove all the shims, you need one hardened shim between the spring and the aluminum head.

The 365# is if your cam has .550 lift or about .570 advertised lift. 1.93-1.38= .550

If he has 1.55 springs now, shouldn't he stay with 1.55? If you go to a smaller spring ~1.45, I think you would need a spring locater or spring cup. Then you will have clearance problems.

JMO.

Lonnie

Found the solution, talked to Harold today and he recommended that I used these spring for longevity and best reliabilty: Yes I could have used the AFR Spring but I just did not have a warm and fuzzy about the extra pressure and the long term effect that it would have had on the valve train. Once again it was a pleasure talking to Harold, the man is a total gentleman.
Here are my specs just in case someone can use this info for further reference: I'm using these spring with the .100 longer AFR Valves.

Install Height: 1.880"
Installed Pressure: 128 lbs.
Pressure@1.75= 140 lbs.
Pressure@1.25= 330 lbs.
Coil Bind Height 1.150"
Outside Diameter 1.500
Parts# 73124 $87.00

Yup you need that warm and fuzzy feeling...

and ...

SOLD to bigjimzlll.... smile.gif