Looking to make some more power, welcoming ideas/advice

[GRTfast]

Yeah I realize the motor is pretty mismatched. I’ve considered different heads to get the compression up a bit, and a different cam.

What is a safe compression number for Florida heat and pump gas? 10:1, 10.5:1?

With the right hydraulic roller, what could I expect to make HP wise if I kept the rest of my combo the same? What about if I picked “better” suited heads?

the heads are fine. you would be better off spending the 3k on stroking it and throwing a 3.55 gear at it. you want power, build it bigger or spin it more. why lug the engine and expect performance.

I like my gearing because it makes it decent for highway cruising. I guess ultimately this car is a big compromise. Just looking to make some more power without breaking the bank. Ideally a cam swap without changing anything else would be good, just not sure how much I can expect to gain by doing that.

[mag2555]

I have made 508 hp with bowl ported peanut port BBC heads !
Your rectangular port heads and that Cam are a terrible mismatch!

[Little Mouse]

You dont have one of those monster size bore engine. Cant see any reason with aluminum head you cant run 10.5 compression. Far as I know the thumper cams have silly amount of exhaust duration split. Were me I would get rid of the HEI dist, most overrated thing since teenage nuki.. Up the compression and put a better cam with all the lift you can throw at it with those big heads. Ya if you can spend the money a good set of aftermarket oval port heads like AFR would certainly be better for what your trying to do.

have you ever owned a pair of AFR heads or are you just one of the bandwagon types?

why would he buy a new set of heads, when his exact combo with stock heads would yield the same power?

whats wrong with an HEI? Why is it so overrated?

even stroking it wont help the top end part because of the intake manifold. put a single plane on it. Or rework the Dual plane.

If you find a better head in an oval port under 300 in size for a bbc anyone could afford let me and others know about it. I did not say you absolutely must change the heads just suggesting for the size engine he already has. You have a hard on against afr heads talk to them about it. Anything I have seen in a fully CNC brodix head sbc or bbc is half again the cost of the AFR heads.

[bobmc]

your gearing seems like fun to drive, if there is no reason to make wholesale changes just change the cam and see how you like it, I would use the lesser of Mike's cams

[GRTfast]

your gearing seems like fun to drive, if there is no reason to make wholesale changes just change the cam and see how you like it, I would use the lesser of Mike's cams

Yeah that’s what I’m leaning towards. Looks like (from talking to him) I can use my lifters and springs, and my p/v clearance should be as good or better. It would be a simple swap and sounds like a decent bump in performance.

[GRTfast]

It’s settled. Mike’s getting some of my covid-19 cash... I went with the slightly milder option so I can use my springs and lifters.

[FC-Pilot]

It’s settled. Mike’s getting some of my covid-19 cash... I went with the slightly milder option so I can use my springs and lifters.

Good call, I would have done the same. Let Us know how it works out.

Paul

[GRTfast]

Considering my specs and the cam I chose from Mike (see below), I am wondering about my intake choice. I see a lot of dyno tests comparing dual plane to single plane, mostly my RPM air gap to a victor Jr.

Seems the air gap is better to 5500, then the V jr is better beyond that, but all the comparisons I see are for a small block with small-ish heads.

Mike says this cam is going to make the peak HP happen at 6000 RPM, and I'd guess it won't fall off as hard as my current cam does due to the wider LSA, which makes me think will will prolly pull decently to 6500 or so.

I'm kicking around trying a single plane, as It seems it will match up to my "big" heads better. Maybe I will loose some bottom end, but when I am really "getting on it" I am spinning it up anyway, and maybe I stand to gain a lot up top with a manifold that matches me heads better.

I guess the main worry is that I would lose some of the good low speed mannerisms that the fully divided dual plane gives me, and really kill the bottom/midrange badly.

Thoughts?

0.030 over 454. 2 bolt main
forged crank, H beam rods
Federal Mogul forged pistons
9.5:1
Brodix bb2 race rite rectangular port heads
RPM air gap with divider filled in
1 7/8 headers into 3.5 collectors, primary tubes ~28 inches (kinda short, necessary for my space constraints)
HEI, 22 initial, 40 all in at 2800, 10 degrees vacuum advance

Cam# BBC, HR73353-75348-110
233/240 @.050"
.353"/.348" Lobe Lift
.600"/.591" Valve Lift
110 LSA

[Dave Koehler]

I'm not going to pick one but I think you will be fine with a single plane and probably even improve things.
At least that has been my experience in the past.
You have enough cubic inch that your reservations about losing low end are needless.
I believe Joe Sherman proved this out more than once on even smaller engines.

I like the heads. Any idea if your compression ratio is measured or assumed from catalog specs?

[GRTfast]

I'm not going to pick one but I think you will be fine with a single plane and probably even improve things.
At least that has been my experience in the past.
You have enough cubic inch that your reservations about losing low end are needless.
I believe Joe Sherman proved this out more than once on even smaller engines.

I like the heads. Any idea if your compression ratio is measured or assumed from catalog specs?

Compression ratio was measured, my dad and I built the engine. Also. and just as a confirmation, the cranking compression pressure matches the Wallace racing cranking pressure calculator number really closely (it takes cylinder geometry, rod length,static compression ratio, and intake valve closing timing into consideration).

It says the cranking psi should be about 160psi, and I get between 165 and 170 on all cylinders.

Would you use the victor Jr if you went to a single plane?

[CamKing]

We've done a lot of testing between single and duel plane manifolds, but none with an engine that has heads that are too big for the application.
Normally, I would say to go with a small plenum single plane, but I don't know how it will be effected by those BB2 ports.

[BILL-C]

I replaced the Brodix supplied springs and retainers on a set of rec port race rites with a set of Comp cams conical springs and retainers and picked up another 300 rpm before we lost controll of the valvetrain on a similar hydraulic roller application. The Brodix dual springs and steel retainers are very heavy and end the party way too soon.

[GRTfast]

I replaced the Brodix supplied springs and retainers on a set of rec port race rites with a set of Comp cams conical springs and retainers and picked up another 300 rpm before we lost controll of the valvetrain on a similar hydraulic roller application. The Brodix dual springs and steel retainers are very heavy and end the party way too soon.

What kind of RPM limit were you finding with the brodix springs and retainers?

[mt-engines]

You dont have one of those monster size bore engine. Cant see any reason with aluminum head you cant run 10.5 compression. Far as I know the thumper cams have silly amount of exhaust duration split. Were me I would get rid of the HEI dist, most overrated thing since teenage nuki.. Up the compression and put a better cam with all the lift you can throw at it with those big heads. Ya if you can spend the money a good set of aftermarket oval port heads like AFR would certainly be better for what your trying to do.

have you ever owned a pair of AFR heads or are you just one of the bandwagon types?

why would he buy a new set of heads, when his exact combo with stock heads would yield the same power?

whats wrong with an HEI? Why is it so overrated?

even stroking it wont help the top end part because of the intake manifold. put a single plane on it. Or rework the Dual plane.

If you find a better head in an oval port under 300 in size for a bbc anyone could afford let me and others know about it. I did not say you absolutely must change the heads just suggesting for the size engine he already has. You have a hard on against afr heads talk to them about it. Anything I have seen in a fully CNC brodix head sbc or bbc is half again the cost of the AFR heads.

The trickflow oval ports are very nice castings, big seat ring and have lots of material. I think they were 280cc. Made just under 700hp on a 496 with them with a basic bowl blend and VJ.

Edelbrock has a few different lines of heads that are great... His heads arent a problem.. Im not suggesting him change his heads, because he won't gain anything by switching.

The BB2 heads are only 300cc 30cc smaller than a 990 casting. And flow 60 CFM more. The air speed is a lot better than the old rectangle ports.

His intake and cam are the restriction. He has addressed that. I would suggest a victor o if he wants to keep the velocity for street driving over a victor r.


I dont have a hard on against AFR.. They are just the most overrated cylinder head known to man. I love them, because I pick up huge power after I port them.

[GRTfast]

have you ever owned a pair of AFR heads or are you just one of the bandwagon types?

why would he buy a new set of heads, when his exact combo with stock heads would yield the same power?

whats wrong with an HEI? Why is it so overrated?

even stroking it wont help the top end part because of the intake manifold. put a single plane on it. Or rework the Dual plane.

If you find a better head in an oval port under 300 in size for a bbc anyone could afford let me and others know about it. I did not say you absolutely must change the heads just suggesting for the size engine he already has. You have a hard on against afr heads talk to them about it. Anything I have seen in a fully CNC brodix head sbc or bbc is half again the cost of the AFR heads.

The trickflow oval ports are very nice castings, big seat ring and have lots of material. I think they were 280cc. Made just under 700hp on a 496 with them with a basic bowl blend and VJ.

Edelbrock has a few different lines of heads that are great... His heads arent a problem.. Im not suggesting him change his heads, because he won't gain anything by switching.

The BB2 heads are only 300cc 30cc smaller than a 990 casting. And flow 60 CFM more. The air speed is a lot better than the old rectangle ports.

His intake and cam are the restriction. He has addressed that. I would suggest a victor o if he wants to keep the velocity for street driving over a victor r.


I dont have a hard on against AFR.. They are just the most overrated cylinder head known to man. I love them, because I pick up huge power after I port them.

You'd run an oval port intake on rectangular port heads? Interesting. Tell me more. Do you blend the oval ports in the intake to match the rectangular port gaskets, or just bolt it up and let it eat?