|
|
|
|
Original Message
|
| Ed heads get different restrictors. |
| By Dave Shoe - 10/12/2003 11:30:35 PM; IP 216.243.176.34 |
Ed drills the oil feed passage larger than factory FE heads, so the standard Holley jet doesn't work.
Orifice diameter typically ranges from .090" to .060", depending on pump, cam, stuff like that. Solid lifter cams allow more oil to flow upstairs, since the rocker is unloaded for part of the cycle, whereas hydraulic cams always load the rocker, keeping the oil feed hole snug against the rocker. some aftermarket rockers create a whole different kind of flow dynamic upstairs, so you've gotta hypothesize, experiment, and speak to folk about your particular setup, being careful to not follow bad advice that is so often offered.
A factor not often spoken of is the length of the restrictor. Whether the orifice is about 1/16" deep (typical carb jet), or 1" or so deep (drilled rod), the flow can vary greatly just by the length and chamfering.
The port to restrict on each head is readily available with the rockershafts removed. It's the port that travels up through the head to the drip tray. Since I don't know exactly what restrictor is preferreed for Edelbrocks, I'd recommend being creative and experiment a little. Hopefully someone else can clarify. If no one does, the orifice diameter will likely be close to .070", and the weight of your truck will hopefully prevent it from accelerating so hard that oil will tend to slosh out of the poan to the rear of the engine.
I lived through this issue for a couple years, rapidly wearing out bearings and hearing hydraulic lifter clatter on hard turns with an 80PSI/HV pump. When I installed a performance pan, the oiling problems went away and bearings lasted a long time. Still, I'd get the occasional smoke bursts after a hard romp, and eventually moved on to restricting the heads to resolve that.
I've still got a new 100PSI blueprinted pump from FPP which I had the guts to buy 15 years ago but never had the guts to install. I now know how to install one properly, but don't presently have any applications that need these specs. Maybe someday.
I've seen a few FE motors blow, and know of others that have blown because they followed the "written word" on upgrading an FE oiling system. The only good documents on how to upgrade an FE oiling system will start by discussing the oil pan. When you've found one of these articles, thn you are on the right track. Invariably, any article that starts off with "the FE top oiling system is bad", is NOT a good article, as top oiling has always provided great performance on the track. The sideoiler came about because of the Cammer's unique oiling requirements, not because there was a noted deficiency in the FE's top oiling system. The topoiling FE is a great racing oiling system, and has proven itself for decades, despite what many writers will have you believe.
You don't need to run drip trays. Just get a good balance to your oiling system, and start thinking of what type of pan and pump you will install next convenient chance you get.
Do a forum search for the terms "sucking air" or "starvation" or "bad writing" (use quotes) to maybe find some detailed threads on the topic.
JMO,
Shoe. |
|
|
This thread, so far...
|
|
|
|
Post A Response
|
|
|
|
|
|