94 Z28, old mans car

1/4 turn would help alot but that cama dn boost will want 175-180 lbs of pressure at 15 psi of boost.

Lloyd

Quote:

---

Originally Posted by NightTrain66

I bet thatw as valve float then.

those lobhes are pretty aggressive and need quite a bit of pressure N/A

Once you add 10 PSI of boost you have 10 psi of pressure on the back of intake valves trying toi hold them open and that will eat up about 25 lbs of seat pressure.

More boost pressure would eat up even more spring pressure.

If the heads and the cam were not set up for a boosted set up (extra seat pressure on springs and slower ramp speed on closing side of intake lobe) floating the valves would be a DEFINITE possobility/probability.

As fara s the blow by causing oil to come thru the guides/seals, it makes sense that this could happen but I ahve never had a car with severe blow by diagnosed and tore down looking for that. Once the blow by was realized (broke piston, etc) the engine was always tore down an completely went thru so i never chased problems like that or looked for culprits.

Was there any oil pushed or dripped thru at oil pan, timing cover, valve cover gaskets, etc?

Lloyd

---

No, nothing pushing out of gaskets, just the breather really badly. It only saw 7 psi. everyone had us scared we broke something since blah blah blah, but in reality, it probably wasn't a big deal. Oh well. I will be using that cam in my impala. Thing is, there could've been float before the boost from what you are saying. What springs am I going to need to handle it na? Those lunati's? Patriots? Etc.

If the heads are LE2 heads and have Lunati 73925 or Patriot dbl springs on them they should have plenty of pressure for N/A. I would have set them up at 155 lbs on th seat when the springs were new but they can lose a lil pressure.

The 228/234 .592/.592 lobes will need 140 lbs of pressure to remain stable with perfect rocker geometry, perfect PR length, perfect lifter preload, etc, The more these things are off, the more pressure needed to remain stable.

Add 7 psi of boost and that will eat up 14-20 lbs of seat pressure causing valve float if the spring doesnt have that extra 14-20 lbs of opressure to lose.

Springs can also lose a lil pressure also.

If the guides and seals were bad it would have had a lil puff of oil smoke out of tail pipe on start up and get pretty gunky in the ports and hedaers pretty quick. If thats not there then i would assume the seals were in good shape for a long time and just recently went bad if they are bad. Maybe the boost/blowby effected the seals if they are now bad. ???

There are videos of "valve float" on Youtube and you can see the valve stem doing crazy things and wear guides pretty quickly depending on how bad it is. Some of those videos are to the extreme and parts would break pretty quickly under that trauma in some of the videos but it does at least show what kinda stuff is going on even though it is to a myuch lesser degree.

Lloyd

email me a pic of the springs and I'll knmow what they are.

just have them checked to see what pressure they currently have and I would put them back at 155 lbs on the seat if they are not there now. that will be fine for that 228/234 .592/.592 cam N/A.

Lloyd

its the patriot duals, nice and shiny. ill probably be sending my heads to you for the impala. gotta get the trans first. so when ill do, ill throw a note in the tote to set them up for that cam

Just dropped the splayed 4 bolt 383 block off to Karl Ellwein, he is gonna work his magic on it. About to drop off the Camaro trans for upgrades and my trans to be built to @Cahall and say hi to the pups.

Great seeing you and Osie today. 1 update and one more Pro Race 4L60E on deck.

Frank

It's official, ERE #59 http://www.ellweinengines.com/ERE59/ERE59.htm

Attachment 32010Attachment 32011

Pretty things. Karl said crank should be back tomorrow from balance, then ASSEMBLY!

Every time I see this thread title I miss the comma....and say to myself..my 94 isn't an old man's car