FE Power Forums
FE Power Forums => FE Technical Forum => Topic started by: fallguy72 on June 07, 2015, 09:31:38 AM
-
445 stroker using a comp cams 280h cam 230/230 @ .50, lobe lift .306, valve lift .530, comp cams recommended springs 926-16 used on 66gt heads transmission shifts @ 5000RPM in drive and i can feel it valve floating just before shift point. any ideas, shorter push rods or something easy would be nice. has anyone changed valve springs in the car? if i push it it might get to 5400 RPM. my 390 last year with the same cam pulled hard all the way to the rev limiter @ 5800, this sucks.
-
Can you measure installed height?
.530 lift will give you 220 lbs of pressure added to the closed pressure. At 1.81 installed, the spring will be be about 100 plus the 220, which should be decent assuming you aren't running two piece retainers
However, if you have a 1.90 installed height or greater, you could have some bounce issues more than float.
You may not even have the springs you thing too, I have seen mis-packaged springs before
Don't push it until you figure it out, it just beats up parts. You can change them in the car, but you need to determine installed height and pressures
-
....and i can feel it valve floating just before shift point. any ideas, shorter push rods or something easy would be nice. 390 last year with the same cam pulled hard all the way to the rev limiter @ 5800, this sucks.
I wonder if you have another issue that only makes it seem you're at valve float. A 445 versus a 390 needs more of just about everything. While I'd also measure your installed height and maybe yank a few springs to check open spring pressure and height, I'd also check to see that it's not running out of gas or suffering another malady. What is your fuel pressure, how do the plugs look after a 5,000 rpm run and a clean shutoff? Are the valve tips and/or rocker pads getting hammered due to insufficient spring pressure?
-
Same rpm every time might rule out running out of gas, checked ready to run distributor for a possible rev limit in there and didn't seem to make any gains. the old springs had some shims on some but not all and worked better than this. i will have to learn how to measure these things as i go.
-
Pull a valve cover, find a spring that has no pressure on it and measure the height of the spring as accurately as you can from the bottom of the spring to the top where it touches the retainer. That is the first step
Stock FE height is 1.81-ish, you want to be precise, although that is tough with standard ruler, it is closer to 1 3/4 than 2 inches. If it is closer to 2 inches than 1 3/4, then you may have an installed height problem.
Lowes sells some small metal rulers that can help you
-
If you are planning on pulling the valve springs off in the car try this. http://www.ebay.com/itm/Valve-Spring-Compressor-Ford-FE-390-427-428-Cobra-Jet-Mach-1-Shelby-/261919298424?hash=item3cfb9b5378&item=261919298424&vxp=mtr I just used this on my car a few weeks ago and couldn't be happier with it. Just fyi, I had absolutely zero luck using the supplied rope with the kit, instead I just used a traditional air valve holder and worked great. I also added a 1/4"NPT shutoff valve after the air fitting to make things much easier instead of cranking the regulator knob constantly and wasting much more air. This doubles for use on 3/8" stud mount rockers also, so it works on several Ford motors. ;) Also, while air pressure was applied, I used a 9/16"-3/8" drive socket and a hammer to break the keepers loose from the retainers before trying to remove. If not, you may be fighting these for a while.
-
Stock FE height is 1.81-ish, you want to be precise, although that is tough with standard ruler,...
I'd say it'd be a little more than tough to get an accurate measurement with this method...especially if the engine is still in the car.
If you have some sort of drafting compass or something similar like the image I posted, that makes it much easier to get a semi-accurate measurement. Especially if you have a caliper to measure it with. I've got a few of these I've kept over the years just for measuring in tight spaces.
I wouldn't rule out fuel either. It can act the same way.
-
Stock FE height is 1.81-ish, you want to be precise, although that is tough with standard ruler,...
I'd say it'd be a little more than tough to get an accurate measurement with this method...especially if the engine is still in the car.
If you have some sort of drafting compass or something similar like the image I posted, that makes it much easier to get a semi-accurate measurement. Especially if you have a caliper to measure it with. I've got a few of these I've kept over the years just for measuring in tight spaces.
I wouldn't rule out fuel either. It can act the same way.
It isn't that tough, granted it wont tell you 1.81 vs 1.82, but you can get pretty close to see if he wants to pull it further down. Can't use your 1st grade teacher's wooden knuckle basher, but a little pocket ruler does just fine
-
The 926-16 ain't enough spring. Might have been marginal when brand new, but will "go away" after some use. Its a single & only 109 pounds on the seat at 1.800" installed, and 317 open at 1.300", with a 415 pound rate. Slipping a .060 shim under it will pick you up +/-25 pounds and will help things as long as you can still retain a little bit of the locator area in the head still poking up through the middle. Cannot allow the spring to wander around on the head...
-
thanks Barry, machoneman, cjshaker and my427stang for all your help I have put in a new fuel pump and .060 shims hopefully this will cure my problem. will post 1/4 mile times as soon as i get them this weekend.
-
Looking forward to the results, good luck!
What was your installed height before you put the shim in?
-
Close to 2"
-
Well if your measurements are accurate, that .060 won't be enough to solve the issue.
Was that a measurement from the head (or top of an existing shim) to the bottom of the retainer? In other words, the height of the spring only, not the thickness of the retainer
Barry's recommendation was based on a 1.80 installed height being "too loose" if you were at 1.90 or 2.00, it would make the starting point even worse, requiring more shim or even different keepers to gain more, or new springs.
I hate to delay racing, but it's pretty rough on parts when the valve train is uncontrolled. May want to consider getting an accurate installed height to accurately close up the space the spring sits in.
If you did go with .050 keepers and your .060 shim, that would be .110 total and worth about 45 lbs seat pressure. Depending where your height is now, that could do it on the cheap
-
New fuel pump and .060 shims the car runs great all the way to 5500 ish 12.87@103 in a 3600 lbs Fairlane with 3.89 gears
Very happy
-
Glad to hear, thanks for circling back and updating
-
2X for the update.
-
New fuel pump and .060 shims the car runs great all the way to 5500 ish 12.87@103 in a 3600 lbs Fairlane with 3.89 gears
Very happy
Amazing what just a 1/16" of extra squeeze will do for you :) Good info for people to use as research!!
-
Amazing what just a 1/16" of extra squeeze will do for you :) Good info for people to use as research!!
What's probably happening is that he's getting closer to coil bind at full lift. My work years ago on the SOHC valvetrain showed how this quiets down the surging motion of the spring coils at high rpm. I found that setting up for around 0.050" from coil bind at full lift gives you the full benefit while staying safe. The NASCAR guys run about 0.003" from coil bind :o :o
-
What's probably happening is that he's getting closer to coil bind at full lift. My work years ago on the SOHC valvetrain showed how this quiets down the surging motion of the spring coils at high rpm. I found that setting up for around 0.050" from coil bind at full lift gives you the full benefit while staying safe. The NASCAR guys run about 0.003" from coil bind :o :o
That was a pretty cool test series. I think we all learned/confirmed a lot.
-
Hey Barry---
What we've just seen in this thread is one of the reasons why this site is unique.
Jay, and all the rest of you, we're doing a good thing here.
KS
-
Hey, Bill! Can you repost a few of your SOHC spring vids again? They were so cool and with the passage of time, I'll venture newer members never saw them.
-
So if the 60 thousandths shim is not enough and it made it ok for now is there more power to be had by doing it properly??
-
Hey, Bill! Can you repost a few of your SOHC spring vids again? They were so cool and with the passage of time, I'll venture newer members never saw them.
Sure! Give me a couple of days to get some family out of town and then dig the videos up.
-
i saw this issue on a dyno pull the other day.everyone thought it was valve float by the way it sounded,but it turned out to be a loose distributor wire.
-
Hey, Bill! Can you repost a few of your SOHC spring vids again? They were so cool and with the passage of time, I'll venture newer members never saw them.
Sure! Give me a couple of days to get some family out of town and then dig the videos up.
Great! I'm sure many will enjoy!