ChevelleNut wrote: ↑Tue Dec 08, 2020 4:05 pm
I'm building (very slowly) a 489 BBC for my 1/8 mile bracket car. I thought I had it all figured out on what I was going to do, but now, since I've got all the parts, I'm second guessing myself. Here's the specs on my engine....
489 BBC
12.5:1
Mechanical flat tappet
262/265 @ .050
.620/.629 lift
Brodix RR BB2 Plus 312cc rectangle port
Weiands Team G p/n 7522 4500 intake (built in 1" spacer w/ long runner dividers extending into plenum)
1050 Dominator
I'm guessing to be shifting at 6700. With the 270 Oval RR heads flowing the same numbers (a little better) up to .650, did I mess up by going with the 312 rectangle ports? I may be over thinking it. I tend to do that. Lol
You may have made a middle of the road choice of heads. Don't compound it with an incorrectly specced cam.
Post some pics of the heads and the flow numbers and valve sizes and I will spec a cam for you.
DV
David Vizard Small Group Performance Seminars - held about every 2 months. My shop or yours. Contact for seminar deails - davidvizardseminar@gmail.com for details.
David Vizard wrote: ↑Fri Dec 11, 2020 12:56 am
You may have made a middle of the road choice of heads. Don't compound it with an incorrectly specced cam.
Post some pics of the heads and the flow numbers and valve sizes and I will spec a cam for you.
DV
1980RS wrote: ↑Fri Dec 11, 2020 10:32 am
What did you run at the track with the old engine combo and the new setup?
It's getting a whole re work, front to back. I honestly can't remember what it ran. Last engine it had in it that went down the track was a 396. It was my dad's car. He pulled the 396 and installed a 427, but was never able to make it to the track after getting it in there. His health had gotten too bad. After he passed, I was going to get it to the track, but had to pull the engine due to warped heads and non sealing head gaskets. I built the 427 and put in my 68 Chevelle street car and started building this 489 for the race car. It's been a while since it's moved under it's own power.
1980RS wrote: ↑Thu Dec 10, 2020 9:06 pm
You need some more cam with those new heads. You may need like others have said over .700 lift. PM me I have a really nice low use Lunati I am not using and need a smaller one for another project, make you a swap.
I appreciate the offer, but I'm going to keep my cam. I've got a new, bigger Lunati sitting on the shelf, but it's a little too big, IMO. I'll hang on to it too, because I have a plans later on down the road for a 525 build. At the rate I'm going, I might never make it, but hey, a guy's got to have plans anyway.
1980RS wrote: ↑Thu Dec 10, 2020 9:06 pm
You need some more cam with those new heads. You may need like others have said over .700 lift. PM me I have a really nice low use Lunati I am not using and need a smaller one for another project, make you a swap.
I appreciate the offer, but I'm going to keep my cam. I've got a new, bigger Lunati sitting on the shelf, but it's a little too big, IMO. I'll hang on to it too, because I have a plans later on down the road for a 525 build. At the rate I'm going, I might never make it, but hey, a guy's got to have plans anyway.
David Vizard wrote: ↑Fri Dec 11, 2020 12:56 am
You may have made a middle of the road choice of heads. Don't compound it with an incorrectly specced cam.
Post some pics of the heads and the flow numbers and valve sizes and I will spec a cam for you.
DV
both heads have more than enough flow to support the displacement at 100% VE at that rpm. you are probably right about the 312 being a little bigger than you need, but as said above the right cam will make that a non issue, and you will have a head that you can grow with.
"Anyone who thinks the low RPM engine will be faster just does not have as much experience as the rest of us" -The late, great Joe Sherman.
You wont beat anyone if you do everything the same as everyone.
Chevelle, your are fine with heads. We have run bigger heads and not have problems. Is your cam wrong, well it not optimum. But it's what you have have. Gutted car also means not street driven, you your fine with the parts. Your cam and possibly short tire are holding you back some.
Best bet and piece of mind now is TO SELL THE SMALL cam. Get a better suited cam and don't look back. That deal should be able to hit 9's.
Try an RPM Air Gap and a 4150 1000hp on that engine. Buddy ran that on his 505 BBC with Dart 335's and made 802hp and over 700lb of tq. with those two items, dyno guy was shocked. I have had better luck with my 1050 2 circuit than my 8896-1 3 circuit at the track.
The intake is going to hurt you and I hate to say it because I ran team g intakes on small blocks for years and still do on my sbc corvette.I built a bbc for my z/28 I also bought a profiler sniper jr intake when I built this engine it is a 511 on e85.When I first built the engine the intake needed to be milled at the bottom.At the time even though I knew it didnt port match and ran the car.It ran 108.9 mph at 3520 lbs ithe 1/8 mile.I finally got some money together bought a team g to run the car with until I could send the sniper intake to have it milled.The car slowed down to 105 mph.I got the sniper jr back and reinstalled the car now runs 112.6 mph.That is a major difference in horsepower I was suprised at the difference but no other changes were made except the intake.I love team g on my sbc but the sniper is superior on the bbc
I just got to say this.Get rid of the little cam match the cam to the heads at that kind of compression your going to choke that big block for air with less than .700 lift.Big blocks like air.
Here's the specs on my engine....
