69vetteny

I recently completed a 406 build using the following:


Dart SHP 406
Eagle Crankshaft 3.750 ESP-440037505700
Eagle 6” H Beam Rods 6000B3D
Compression 10:2:1
AFR 195 Street Eliminator Heads 75cc AFR-1038
Comp Cam S/S/ Rockers 1.6
Edelbrock Performer RPM Air Gap EDL-7501
Holley 780 Vacuum Secondary
Lunati Bootlegger XXX08224HRLK
Hyd Roller
Duration 276/300
Duration @ .50” lift224 int / 236 exh
Lift 554/554
Lobe Separation 108


I am satisfied with the dyno results of 537 TRQ & 500 HP, however I was hoping they would have been slightly higher. Any suggestions to increase HP/TRQ would be appreciated. The motor is being used strictly for street use with a Tremec TKO600 5 speed.

96 lt-4

A little more duration and less split perhaps?I will wait for those smarter than me to chime in.

cooper9811

AFR heads tend to respond well to little to no split. I've run AFRs on my last 3 engine builds - If you want to get a little more, this could help.

69vetteny

During the build I was considering installing a cam similar to what you are referring to Comp Cam 286HR


Duration 286 / 286
Duration @ 0.50" Lift 230/230
Valve Lift 0.56 / 0.56
Separation 110

gkull

When you have a 5 speed you can enjoy bigger duration numbers than automatics.

I have a considerably larger cam in my daily driver 383 with the tko 600

It's the third roller cam. Before I got it right my advice is to never take advice from anyone that doesn't have the same kind of build. If they don't have a roller cam and a bigger ci.sbc they just don't understand the other thing as ci goes up so does the need for duration

It is not just the head that determines the duration split. It is the whole exhaust system and back pressure. I have afr 210 heads with hooker sc and 3 inch dual exhaust 236/242 112. It is fun to drive. My old 427 sbc had. 227 cc heads and 250/256. 110. You are right in the middle on ci. So you would need @242/248. To have the same manners as my builds

It would be mild with a 236 242 112, but you would really go up on the Hp

cv67

Id drive it first before changing anything thats an awful lot of torque for the st. Lots of tq in a useable range. What were you expecting?

76strokervette

gkull

I was looking at your dyno sheet and your motor is very efficient on BSFC.

I was trying to figure out why your motor didn't have detonation problems with such a low intake duration. The reason is the 108 LSA bleeds of or has reversion at lower rpm. TQ is a function of ci and compression ... going to bigger cam would increase hp and the TQ would kind of stay the same.

As to driving a 500/500 vette. Not a big deal and you will be wanting more in 6 months

diehrd

Personally I would not have used 195 heads on a 406 . 220 would be my choice and my 'Opinion" for what it is worth tells me you're HP would be up about 25 to 35 and tq be about the same.

As fa as Gkull saying 500 will have you wanting more he is possible right but that happens at 600 to lol

ajrothm

Very good numbers for such a mild cam.. I'd drive and enjoy it, it should have excellent manners.. However I could see a cam swap netting you another 30-40hp.

As mentioned the heads are a little small for 406" and a quest for more peak HP...you could have them worked and probably gain 20-30hp from that, however it's probably not worth the trouble/cost.

Honestly I'd put it in and drive/enjoy it.....you're not really gonna feel 20-30hp on the street anyway. You have a really nice, well matched street combo, it will have great driveability and probably even be decent on fuel economy. Can't ask for more then that.

NewbVetteGuy

Doesn't AFR have a CNC profile already sitting loaded in their CNC machine that takes AFR Eliminators and makes them AFR Comps? (obviously the CNCing wouldn't upgrade the springs or valves) --If so, you might even find out how much it would cost to mail them back to AFR and have them CNC port them to a comp profile and checkout the air flow increases and intake port increase. I remember some monsterous numbers from the AFR Comps... (Although a bigger cam would probably be considerably cheaper...)


Adam

69vetteny

I do believe the HP & Trq for this build are ideal for the street. The motor will not be installed in my Vette for several months due to a frame-off resto I am about to undertake. Since I have the extra time I thought it would be a good idea to explore some alternate cam options that may increase hp & trq while keeping the 195 heads and good street manners. Gkull thanks for the advise on the cam specs. What sort of manners would I expect with the 248/248?

gkull

Your compression ratio and H-roller max rpm would become a liability if you exceed about 242 degrees. Generally I would tend to limit a h-roller to 6500 rpm rev limiter. Something like a 248/248 might put your power at a very high rpm.

I would not worry about afr 195 heads on a 406. These new heads flow as much as the older AFR 210s. Also bigger than about 195's the rpm air gap exit port would be smaller than the head port and then you have to jump up to some single plane intake.

Just look at it this way. your 224 is low duration adding 20 degrees is a massive change and it might be beyond the limits of your intakes ability of flow, compression ratio, and requiring 1 7/8th headers.

As I understand it and I don't have scientific factual data to back it up, But you tend to only find single pattern cams in drag cars that have open header exhausts.

I have custom billet steel sleeved dizzy gear cams in both of my present motors. I went to the Comp Cams lobe charts and got racing lobe profiles and had the valve timing events set to my specs. they use the idea of Crane cams where they are 4 degrees retarded compared to the equivalent comp cams extreme line of cams. so mine have less reversion and more fuel efficiency. My 434 cam also has the altered firing order 2/7 swap. I'm a solid roller person.

MotorHead

As others have said, your cam is a little on weenie side, you should be looking at 245-250dur @ .050"

You will pick up a substantial amount of HP and Tq will be a little higher across the RPM range it will not go lower.

OMF

It all depends where you want your power. Using a 245-250 as MotorHead suggests will give you best power in the upper RPM range, while using your cam gives power in the lower range.
For a strictly street 406 engine I'd use something in the 232-234 @ .050 range. with less split in the intake and exhaust duration.
I'm building the same basic engine as you (including the heads), and was concerned about my cam duration split. I was advised to keep the split with these heads at about 3-4 degrees more on the exhaust.

These heads with a roller cam don't need huge duration to get good streetable power.

Kubs

Not to beat a dead horse, but yes that cam is on the smaller side for maximum HP. For a fun street engine you have enough to be happy in my opinion. Those smaller port heads will keep air velocity up at lower RPM and part of the reason you are making good torque numbers. I would leave it alone if I were you and enjoy it. Also, that setup is very gentle on the components so it should be very reliable as well.

cv67

we dont know what rearend gear he has, driving style or manners hes after what he built may be ideal at this point no need for steep gears for most fun street driving why change anything at this point may be ideal for him.
Some of us can tolerate less low end tq big cams etc others find they dont like it at all. There is no free lunch with this stuff even the efi guys

Big dyno #s flow #s etc arent they only way to make a fun street car esp thats getting driven a lot

Jebbysan

240+ duration@.050 cam, and a High flow single plane intake.....
the air-gap is a cork above 500hp on a small block.......
I run a ported Team G on mine..and a cam with 244/244@.050....something like that or the Dart single plane works well.......Brodix HV1 intake also works well........
AFR's Titan is the end all do all of intakes but you need a lot of clearance and a lot of $$$$$$$
That combo should make another 30hp IMHO.

Jebby

76strokervette

Another thing to consider is the differential and gearing. I believe the current power level is already near the limits of the stock differential.
If aggressive driving and sticky tires are used the stock unit may not survive with the power he already has.

Jebbysan

Install good motor mounts too.......my first 1-2 powershift with the Nittos popped a brand new GM mount apart........

Jebby