401 sbc ready for the Dyno

[HQM383]

Been building a 401 sbc for the past 12 months. All buttoned up now and should be on the dyno by the end of next week. For the time being let’s have a bit of fun and guess the hp and tq. The intention of this engine build is to go into my 1972 HQ Holden 2 door (similar size of 68-69 Camaro) with TH350, 5k converter and 4.11:1 gears and go weekend cruising, car meets etc and the occasional run down the strip with high 10’s the goal but wouldn’t be disappointed with low 11’s. Engine spec is as follows:

Dart 1 pce rms SHP 4.125” bore
Scat 3.75” crank
Scat Pro Series 6” rods, 7/16” cap screw
Wiseco ProTru Street forged pistons
Hastings premium ductile 1/16” - 1/16” - 3/16”
Mahle Clevite H series bearings
ARP main studs
Melling Shark Tooth oil pump +10% volume

11.57:1 static compression ratio

Trickflow Twisted wedge G1 (13 degree intake valve angle) 2.02” / 1.6” valves. Ported.
MCSA at pinch 2.0”. Burr finish
Intake @ 28”
0.100” - 74.2 cfm
0.200” - 145.5 cfm
0.300” - 196.0
0.400” - 235.2 cfm
0.450” - 252.4 cfm
0.500” - 255.4 cfm
0.550” - 256.6 cfm
0.600” - 257.0 cfm
0.650” - 255.0 cfm
0.700” - 256.6 cfm

Exh @ 28” (no pipe)
0.100” - 67.4 cfm
0.200” - 112.3 cfm
0.300” - 147.6 cfm
0.400” - 176.5 cfm
0.450” - 187.0 cfm
0.500” - 195.8 cfm
0.550” - 202.8 cfm
0.600” - 208.6 cfm
0.650” - 213.5 cfm
0.700” - 223.0 cfm

PAC 1237 springs 1.750” installed height
Titanium retainers with 10* locks

Comp Cams mechanical roller
Intake lobe #12558. 284* @ .020” / 256* @ .050” / 181* @ .200” / .410” lobe lift / 0.640” net lift at valve with 1.6:1 rockers
Exhaust lobe #4221. 308* @ .015” / 262* @ .050” / 176* @ .200” / .383” lobe lift / 0.583” net valve lift with 1.52:1 rockers
108 lsa. 3* advance.

World Motown single plane intake, burr finish matched to 1205. Outer runner entry 3.041”sq, inner runner entry 2.93”sq
Race Demon 975cfm (gold sleeve) with Braswell downleg boosters
Holley 130gph 6 valve Competition mechanical fuel pump

Progression Ignition distributor, Moroso Ultra 40 leads and ngk 7 plugs

1-3/4” 4 into 1 headers 3” collector

Mezier electric water pump

What have I forgotten?

HP?
TQ?

My guesstimate 560hp @ 6100rpm and 530ft/lb @ 5000rpm.

*yes, heads are the big cork in the system. Budget build and I came across these heads already ported and brand new never bolted on an engine before condition with valves for AU$800. Previous engine had same heads so I was already kitted up for some of the unique required parts.

[bob460]

Ok as a Ford man i'll go..........

525hp @5900rpm

520tq @4500rpm

Good luck and who's dyno?

[HQM383]

Ok as a Ford man i'll go..........

525hp @5900rpm

520tq @4500rpm

Good luck and who's dyno?

Thanks. I’d be happy with that too.

The guys at Octane Alley, North Geelong. Drop off this Friday, they will set it up next week. Because they have no more dyno work booked in after me after the run-in they will leave it on there and I can come in when I can to do the tuning and changes I have planned. They will operate of course. So a week or so set up on the dyno. At this point have four carbs to play with and Progression Ignition timing table to dial in.

[HQM383]

Cam card and valve events as dialled in. Installed with 0* crank keyway the cam was 4.7 degrees advanced.

[Tom68]

520 TQ 590 HP
Hope you're taking some exhaust rockers (1.6 or 1.65 ) to see if it adds above the HP peak and maybe doesn't hurt elsewhere.

[HQM383]

520 TQ 590 HP
Hope you're taking some exhaust rockers (1.6 or 1.65 ) to see if it adds above the HP peak and maybe doesn't hurt elsewhere.

I do have 1.6 rockers but only for 3/8" studs. Simulation showed the 1.52:1 exhaust rocker gave up a little below peak tq for a little more above peak tq and carry further. I will be interested if it carries the hp as sim predicts. 557.8hp @ 6000hp and 557.97hp @ 6500rpm.

[DCal]

Very close to mine. You have 20 degrees more on the cam but smaller heads and you have an electric water pump so I'm gonna guess it's close to a push: 562hp . 534tq. I don't have a sim so this will let me see how mine compares.

[Tom68]

520 TQ 590 HP
Hope you're taking some exhaust rockers (1.6 or 1.65 ) to see if it adds above the HP peak and maybe doesn't hurt elsewhere.

I do have 1.6 rockers but only for 3/8" studs. Simulation showed the 1.52:1 exhaust rocker gave up a little below peak tq for a little more above peak tq and carry further. I will be interested if it carries the hp as sim predicts. 557.8hp @ 6000hp and 557.97hp @ 6500rpm.

It'd make a good sim v real world test.

[Steve K]

I've got a smaller cam, bigger heads and I made 540 hp and 525 tq so I'll say 250 hp and 300 tq...but the dyno probably wont register that low lol, so 550hp and 525tq

[HQM383]

520 TQ 590 HP
Hope you're taking some exhaust rockers (1.6 or 1.65 ) to see if it adds above the HP peak and maybe doesn't hurt elsewhere.

I do have 1.6 rockers but only for 3/8" studs. Simulation showed the 1.52:1 exhaust rocker gave up a little below peak tq for a little more above peak tq and carry further. I will be interested if it carries the hp as sim predicts. 557.8hp @ 6000hp and 557.97hp @ 6500rpm.

It'd make a good sim v real world test.

To be honest the sim showed the difference would almost be margin of error on the dyno so I went for what's easier on the valve train, and considering converter, usable.

[HQM383]

Very close to mine. You have 20 degrees more on the cam but smaller heads and you have an electric water pump so I'm gonna guess it's close to a push: 562hp . 534tq. I don't have a sim so this will let me see how mine compares.

The heads interest me as whoever ported them knew how to prevent them backing up after .500". I have another pair that does just that, 10cfm higher peak but goes the other way after half inch lift. The guy who flowed these newer ones said they were quiet. My assumption is it will like this intake lobe @ 256° due to the time exposed to the low yet consistent flow.

[HQM383]

I've got a smaller cam, bigger heads and I made 540 hp and 525 tq so I'll say 250 hp and 300 tq...but the dyno probably wont register that low lol, so 550hp and 525tq

Thanks. And again, I'll be happy if I get those results

[skinny z]

Progression Ignition distributor,

Not to derail but this caught my attention. Is this the programmable model that's been in discussion here?

As for HP and TQ?
I like this guess...
"560hp @ 6100rpm and 530ft/lb @ 5000rpm".

Good luck.

[xanadu]

Ill guess 580HP@6200 / 530Tq@5100
Really interested to see the results.
All the best.

[408 Nova]

I don't have a guess on power and torque, but I have a set of those original Twisted Wedge 13/23 degree heads that I ran a cartridge roll through back 25 years ago. We left the big ledge in the bowl which I'm assuming the fellow who ported your heads did also.

They were on a factory block Lunati 408 kit engine, with dish pistons to clear the intake valve, and with a stock Edelbrock 2925 and a stock 750 double pumper carb (4779-9).

The cam was a Lunati 40146 solid flat tappet ground on a 102 LCA and installed on a 98 degree ICL. The rockers were and still are the matching Summit Racing 1.5/1.5 rockers intake/exhaust. These heads have a pushrod tube, and the 1.6 Harland Sharps I wanted to try on the intakes moved the pushrod cup toward the rocker stud too far and ran into that tube. So they weren't tried of course.

The rest of it was a Performance Distributor's HEI, 1 3/4" Hooker Super Comps with no collector extensions and no exhaust, TCI Streetfighter Turbo 350, a Streetfighter 10" 3800 converter, 4.56 gears, and 26x10 MT slicks in a 3200 lb race weight 72 Nova street machine.

It ran 6.90's at 98+ mph in the eighth with 36 degrees total timing and stock jetting when it was 100 degrees and one million percent humidity back in 2001 at Jackson Dragway in Jackson, Tennessee.

Anyhow, I said all that to say this: you should run 10.90's quite easily with your setup.