406 Build...Advice Please!!

[daytonayellaz]

I was hoping that everyone with experience on these 406 builds would lend a ear and offer some direction.

Im building this for my 67 camaro convertible and I have a viper 6-speed to go behind it...and I do want to use 6th gear, so low end grunt is real important! I want to run on pump gas, with NO fear of detonation. Thats why I pulled the pistons ( see below, they were flat top hypers) The car may see the track just for fun, but will mostly be street driven. I want to drive it to family reunions which are 800 miles round trip.

I bought a fresh built assembled 406 shortblock from a kid in my area who needed some cash and had to sell. I pulled it down to change pistons (which I have for sale on here if you want to see what thay were)

Here is what I have...

509 block with 2-bolt mains. Has not been decked yet.

Eagle 3.750 cast crank that has been changed over to internally balaced

Eagle 5.7 H Beam rods

AFR 195 alluminum heads with 65cc chambers

Elderbrock RPM Airgap intake.

Holly 780 carb

Im going to have deck plugs installed in the large water openings on the deck and have the block decked....say .020?? or maybe zero deck it?

Im thinking of D dished forged slugs, to keep compression down and get my quench right after the block is decked.

I have no idea on the cam yet.....Soooo can you help with pistons and cam shaft...and any other things you may see.

Thanks,
Travis

[TnBlkC230WZ]

Not sure why you want to zero deck the block unless you believe the deck isn't parallel. On a mild engine determine what you want the compression ratio to be, then adjust the quench area and CR with your head gasket.

IMO keep the compression to 10:1 +or- a couple of points. small dish pistions should do this

Cam selection will be very important for your power curve.

Once you know your deck height, pistion volume and head volume; several guys have software that will tell you how thick the head gasket needs to g.

[Lowend]

It's a solid combo
If you run a flattop piston it will put compression at ~10.6 which is perfect. just run a good forged unit

I agree with TnBlkC230WZ No reason to zero deck.

Honestly I would probably just toss in a Hyd roller cam along the lines of Crower 00404. It will make a ton of torque and put redline ~6200. I would probably buy a small base circle to make rod clearance a little easier

EDIT - I totally mixed up my part numbers - fixed now

[daytonayellaz]

10.6 is not to much compression for 92 octane??


I was going to run a .039 felpro gasket and with the piston .005 in the hole that gave ma a .044 quench. Now I have no real experience with this, just refering to stuff I have read on line. Thats why Im asking here before putting anymore money out on parts I dont need.

I was decking the block some just to get a good flat surface, while I was at it someone suggested putting the deck plugs in before decking it. I dont have to zero deck it, in fact I think that is to much with the head gasket I plan to use..I just was asking to see what you all thought. Thanks for the replys guys!

[TnBlkC230WZ]

With the right combination of parts and aluminum heads, you can run 11:1. 10:1 is a little safer

[Lowend]

I ran a 10.61 383 on pump gas for years... it's all in the tuning

[Black67SS]

Timing is the ticket to longevity of the engine.As long as you don't get to aggressive(say 32 degrees total) with the aluminum heads you'll have no issues.

[CarlC]

10.6:1 with a flat-top and 65cc chambers? I don't have the calculator handy, but the previous 406 in the car had a -16cc reverse dome and 62cc chambered Fastburns, zero deck, 0.041" gasket, was 10.3:1 ratio. With a Comp 230/236 HR cam it ran with no detonation with 32* timing.

With a 3.73:1 rear gear and a 0.64 TKO overdrive it was very happy on the highway. If using 6th the next smaller cam would have been a better choice.

[Lowend]

I did the math wrong... its about 10.9 - 1
Still doable on pump gas

[daytonayellaz]

OK guys..Thanks for the help so far!

[daytonayellaz]

10.6:1 with a flat-top and 65cc chambers? I don't have the calculator handy, but the previous 406 in the car had a -16cc reverse dome and 62cc chambered Fastburns, zero deck, 0.041" gasket, was 10.3:1 ratio. With a Comp 230/236 HR cam it ran with no detonation with 32* timing.

With a 3.73:1 rear gear and a 0.64 TKO overdrive it was very happy on the highway. If using 6th the next smaller cam would have been a better choice.

Yes Carl, I do plan on using 6th gear some. I had some one recommend thics cam also http://www.compcams.com/Cam_Specs/Ca...?csid=306&sb=0

Is this to much cam? and will it kill my bottom end torque for using 6th gear?

[Doug G]

My old combo was 10.17:1, steel heads,and ran fine on 91. It had a Comp 280H cam and pulled 2.73's to the tune of 13.5 @ 101 and would take 1st gear to 80mph @ 6000rpm (surprised a few "ricers") traction on the street with regular radials was non-existent and 60's at the track were 2.0's all day. Plenty of low end grunt I would go roller in something close to that due to the $hitty oil out there now.

[daytonayellaz]

My old combo was 10.17:1, steel heads,and ran fine on 91. It had a Comp 280H cam and pulled 2.73's to the tune of 13.5 @ 101 and would take 1st gear to 80mph @ 6000rpm (surprised a few "ricers") traction on the street with regular radials was non-existent and 60's at the track were 2.0's all day. Plenty of low end grunt I would go roller in something close to that due to the $hitty oil out there now.

So you dont think that cam I posted the link for is to big for what I want to do??

How do you like the stinger hood?? I was just telling my wife last night that I want to put that hood on our 67 camaro.

[70camaro406]

I've had hyper flat-tops (4-valve relief), in my 406 for about 7 years now (only about 1500 miles, but over 100 1/4 mile passes). I have my timing set at 36 degrees, and I run pump gas exclusively. I've never had a problem. Now I've never been able to lug it any (4k stall & 4.10's), but it saw 6500-6600 at every pass. It has a Scat 9000 crank, 5.7 Wheeler Sportsman lite rods, AFR 210's, and a Lunati solid roller with 250 (int) 259 (ex) duration at .050 with 630" 637" of lift. The heads has 66cc chambers, and I used Felpro 1014 head gaskets (.039").

[daytonayellaz]

I've had hyper flat-tops (4-valve relief), in my 406 for about 7 years now (only about 1500 miles, but over 100 1/4 mile passes). I have my timing set at 36 degrees, and I run pump gas exclusively. I've never had a problem. Now I've never been able to lug it any (4k stall & 4.10's), but it saw 6500-6600 at every pass. It has a Scat 9000 crank, 5.7 Wheeler Sportsman lite rods, AFR 210's, and a Lunati solid roller with 250 (int) 259 (ex) duration at .050 with 630" 637" of lift. The heads has 66cc chambers, and I used Felpro 1014 head gaskets (.039").

Is your block decked any??

[CarlC]

That cam will not be happy in 6th. Mine was a 230/236 @ 0.050" on a 110 LSA and it was just starting to be happy at 2200 RPM.

A friends 406 T56 with 3.73:1 AFR 210 etc. with a Crower 242/246 @ 0.050" 106 LSA would not support 6th until the car was over 85mph.

[daytonayellaz]

That cam will not be happy in 6th. Mine was a 230/236 @ 0.050" on a 110 LSA and it was just starting to be happy at 2200 RPM.

A friends 406 T56 with 3.73:1 AFR 210 etc. with a Crower 242/246 @ 0.050" 106 LSA would not support 6th until the car was over 85mph.

So what cam would be good with my 406 combo and 6-speed ??

[GetMore]

I can't recommend a cam, but I think you actually want to go a little small when you choose one. Build it for torque, since you want to use sixth gear, and you should actually get some good mileage out of it. Plus, it should be an enjoyable motor to drive.
I do recommend calling AFR to see what they recommend, and I would also go with a roller cam.

[daytonayellaz]

How about this cam guys http://www.compcams.com/Cam_Specs/Ca...?csid=158&sb=2 Is it the duration that changes the rpm range ? Will this work well with my AFR195's and rpm air gap?

[Lowend]

First - I don't love that cam... not enough duration for this.

If you want to learn about cams
http://www.iskycams.com/degreeing.php