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Discussion Starter #1
Hi,
After last winter when I swapped my cam and matching COMP springs, I've run into a little problem. When driving high speeds or hard launch and over 4000 rpm, exhaust starts to smoke. I removed the valve covers and noticed that valve seals were no longer in their seats. At some point they've got stuck to the damper springs. I tried to research on Comp Cams pages, but found nothing as their site seems to give me a "Fatal Error".

Any suggestions for a proper stem seal?

Thanks,

Markus
 

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A lot of FE (390-428) builders restrict the flow to the heads. Especially if a high volume oil pump is being used.
The port restriction is typically 2mm to 2.3mm.
To gain access you remove the rocker assemblies. The port is at an angle joining the passage that feeds the rockers along the rocker stand bolt.
 

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I generally do not restrict any more, but you need to make sure the returns flow free, some heads need a little work around the head bolts to get good return flow.

In addition, I run positively located Viton seals, there a number of options I have on the shelf, but you can find what you need yourself. Measure the outside of the valve guide and ID of the spring.

Here is a place that sells them in small packages and has all the dimensions

VALVE SEALS 3/8" - Alex's Parts Sales

I have been using the fixed body style mostly, but some dual spring with damper combos sometimes need the guide machined for the small seal

These two are common for stock heads, but do NOT buy until you measure your guide and the ID of your spring

3/8" X .625" VALVE SEALS, VITON, FIXED BODY, 16 pieces - Alex's Parts Sales

3/8" X .625"-.660", VALVE SEALS, VITON, FLEX BODY TYPE, BBC, FE FORD - Alex's Parts Sales

Either design is far better than stock, but the second design takes up a lot of room
 

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Discussion Starter #8
I'm using Melling high volume pump in my motor. It sounds easier to restrict the flow than improve flow back to pan. Am I right or wrong? If I use a carb Jet as restrictor, how to keep chips out of galley when tapping it? I really don't like the idea of pulling the heads.

Stang, thanks for the links to Alex's. They seem to have exactly what I need.
 

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If you run iron heads, you don't tap it, you just stick the jet in the hole, it stays put, can't go up because of the rocker bolt and the passage turns a corner beneath it keeping it from going down.

If you run alum heads, you need to tap it and run a drilled set screw. In that case, chips aren't really an issue as there aren't many and they come up where they wont do any damage anyway, but if possible it's best to do off the vehicle

As far as limiting it to the heads, in general, there is nothing wrong with doing it, and MANY guys do, however, some people get flooding and blame it on the pump, when its really loose rocker clearances.

By the time they limit it enough to stop flooding, the outer rockers run dry. Seen it probably 50 times, long cruise and a guy smokes an end rocker

Oil on a valve spring is good, and if the returns work well, you get the benefit of additional valve spring cooling. Not that a mild cam needs it, but some of us run .600+ lift and keeping springs cool is good.

Remember, the oil is ALREADY restricted to about a .100 hole by the head gasket, once you get a good positive Viton seal (not white Teflon and not an umbrella) they can live with oil flying around under there
 

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Also things to check....


Are you using the drain back tins?

Did any of the the valve stem seals or any other trash clog up the oil drain backs on the side?
 

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Discussion Starter #12
Also things to check....


Are you using the drain back tins?

Did any of the the valve stem seals or any other trash clog up the oil drain backs on the side?
Yup, tins are there. Heads are iron. No clogs. Seals are stuck at the top of the valve stem.
Since I did not have this problem before cam and spring swap, I'm going to replace the seals with good quality vitons with small OD as My427Stang suggested. If that won't help, maybe then restrict the oil feed.
 
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