Will 2.19" valves clear a 428 bore?

[blykins]

Looking at the Edelbrock heads with 2.19" intakes and 1.73" exhausts....will they clear a 4.130" bore without eyebrowing the top of the cylinder?

[Woodz428]

Not without notching the cylinder....and possibly hitting water. As thin as the cylinder walls are it is not advisable. On top off that you would have considerable valve shrouding that would probably negate, or worse, any flow that they might offer.

[SCOBRAC]

I think they will. We are only talking about .050" of difference between the 428 4.130 (std. bore) and the 427's 4.23" bore. Notching the top of the 428 is far less risky than doing a 427...

Remember we're only talking say .050 chamfer off the top corner. However I would keep the lift to .500.

I know the 2.09" valves that come standard on the e-brock heads will work on the 390's 4.05" bore, add the extra .050" valve radius (half of .100) and they would easily work on a .030 over 428 (4.16)... I wouldn't take the block .030 over just to fit the heads, but it would work.

The question is do you really want 2.19" intake valves??? Valve shrowding aside, how will the car be used? If the answer is in WOT conditions above 6,000 rpm the answer is sure do it. Holman and Moody used 2.19" intake valves as a starting point, as do most modern big block's.

If the answer is, because I can... Sure do it... But if the answers to 1-2 are no, I suggest not doing it.

There is a penalty to be paid on the low end for running too much intake valve. Bigger isn't always better. Sometimes it's just cool to say you have them. Of course you are wasting your money if you don't run enough cam to use the flow capabilities of your new heads... What about compression... 2.19" intake valves and 280 degrees of duration scream for 11.8:1 compression and a pair of 660 mechanical secondary Holley's... That is a slippery slope.

Believe me. It's like having kids. You love them for what they are... I love my 4.25" intake valves, 282 degree duration (at .050) cam and 11.8:1 compression and a pair of 660 Holley's. That is until you fill it up with 103 octane fuel a few times because it diesels when you shut it off running 91 octane "premium" (all we can get here in California).

I do love that it sounds like I'm about to light the candle on a top fuel car when I fire it up. I especially love setting off car alarms ilding down the street... Would I do it again... You bet

[Woodz428]

SOBRAC....4.25" Intake valves?....man you must really have some valve shrouding...

[SCOBRAC]

Lol... Maybe... The tunnel port 427's used 2.25" intake valves. It makes max power at 7200 rpm. It is actually a pretty interesting torque curve Pretty linear and docile to 3200 and then up at a 45 to 6700... It works well on the street below 3500 and really well everywhere else to 7,000.

[blykins]

I was planning on 11:1.... but with a .605" lift on the cam.....I was wanting a revvy motor this time around....6500-7000 would be fine with me. :-)

I'm just doing some brainstorming....planning on building an FE and exploring the options.

[trularin]

So, Michael, when the valves open does the hood flex at the air being sucked in with those monster valves???

Good info, sounds like you have been down the road. I am thinking a 427 or 428 as well.

[bmcmillan]

I'm a little late on this thread but I have just been through this. The Edelbrock heads don't flow enough air to justify the big valves. I suggest you run the diffrent configurations through one of the computer dyno programs. I think you'll see that bigger valves give you no more hp and actually hurt the torque.

I would really suggest the Keith Craft ported Edelbrock heads. IMHO, I think you are wasting your money bolting on stock Edelbrock big-valve heads. Also, get the 72cc heads.

Good luck,

Brian

[blykins]

I was going to buy the heads bare and assembling them myself with the correct cups, springs, and retainers.

Wonder what KC would charge to do some work on a set of heads?

[Clois Harlan]

Blykins,

Go ahead and buy them. I have had mine on my 428 and now my 427 and that is one of the few things I haven't had problems with. No problem with the pistons unless you plan on running a higher lift cam than I had (over .613).

Clois

[blykins]

What compression you running Clois?

[bmcmillan]

I can't overemphasize the value of using the computer so you can change one variable at a time to see the effects. Anecdotal information is not enough. An 11:1 428 will run out of breath way before 6,500 RPM with out-of-the-box Edelbrock heads. Don't believe me, believe the numbers.

Brian