427 SOHC street cruiser HP estimates

[e philpott]

so if you purposely built a low compression mild cam Cammer with small carbs , just what kind of HP would someone expect to make with a combo like that ??.... we're talking street cruiser , will never go to the track or run hard type build , just cool factor and cruising reliabilty not trying to get the most and maybe even the least

reason for question .... my brother has been sending me pict of a black 63 galaxy all aluminum cammer for months now , I ask him what kind of cammer is it ??... who's block , who's heads , ect ect but know one know's any info on the car except its a 427 cammer there for a dyno session and tune the carbs for street cruising ..... any how , the shop finally gets it on the dyno and tunes the air fuel ratio and was very surprised it only made 380 rear wheel HP with this massive engine , it ran good and smooth but if looks could kill this thing made 750 HP ..... so is 380 rear wheel HP on par for a mild cammer build ??

thanks , Eric

[Hemi Joel]

Seems about right to me. 380 RWHP could be about 500 at the flywheel, which isn't too bad if it is only 427 cubes and low compression.

Bye for now.

[jayb]

Rear wheel HP will depend a lot on the dyno, and also on the transmission in the car.  Was it a stick or an automatic?  I've been told that an automatic will usually show poorly on a chassis dyno.

Here's a recipe for a weak SOHC engine:  stock cams, replacement valves that are much heavier than the original hollow stem valves along with the stock spec valve springs, 9.5:1 compression, and stock cubic inches.  An engine like that might only make 475 HP, because it can't rev up into the power band it needs to to make power, and the compression ratio is very low for the seat to seat cam duration.  I saw one SOHC build kind of like this in a magazine once that only made 425 HP, so I think even with a stick 380 RWHP is within the bounds of reason.

[WConley]

Years ago I saw a late 60's Ranchero at J. Bittle's place.  He freshened the all-Ford iron cammer and put the car on the chassis dyno.  350 RWHP was all it could muster!

The transmission was a stock C-6, which is a known power-sucker.  The engine never spun up to any real rpm either.

Still, that's pretty weak!

[e philpott]

its a 482 EFI with stick and thats as much as I know about it ... the guy was clear about it was just for cruising ... it must have some serious torque down low

[Barry_R]

Did one up for a local Detroit are gent a couple years ago.  He drives it everywhere - car shows, grocery store, cruises, ice cream...lots of miles.  It was a factory 427 block, factory cast iron heads, LSM stock replacement cams, factory 2x4 intake.  Had a 428 crank for 454 cubes and 10.5: compression for pump gas.  Made 614 on the dyno.

http://www.youtube.com/watch?v=uS-DTSljDqw

[Heo]

Hmmm interesting So what you say Barry is
that its possible to build a SOHC thats streetable
and reliable?
How are the new Pond SOHC heads can you
build a reliable streetfriendly "dailydriver"
with them running unleaded 98 thats not
dead on low rpm. that you can take for a
2000 miles trip without trunk full of spareparts
and tools?
I gues you could get the same results cheaper
with regular heads  but a SOHC is a SOHC

[e philpott]

apparently there are a few guy's that can build a street cammer

[Barry_R]

I have not seen Pond's heads in person yet, so I cannot give you any kind of valid opinion.  The pictures look interesting.
There is no real reason (beyond expense) that a Cammer cannot be a reliable street engine.

[bmalone]

I would like to give my impressions on running a street-driven SOHC car for more than three years:

Specs are 452 inches, venolia pistons and carrillo rods, CR is ~12:1, ignition is electronic, an 850 DP on the single 4V intake, and Crower cams.

Engine is in a CSX4000 Series Cobra and it has been street-driven - for a lot of enjoyment.

I believe the most important factor that has contributed to streetability is the electronic ignition.  Distributor is a Mallory magnetic-triggered unit with an MSD 6AL box behind it.  And likely choosing 3.5" power valves for the DP.  Car will never load up, same plugs in it the whole time.  I had a whopping 4.5" of manifold vacuum.

And I believe the single most important factor in contributing to healthy power levels was choosing to keep the CR close to what a stock crate motor had.  Used just slightly thicker head gaskets than stock.  Yes, I run a 50/50 mix of 110 and 91, but never in a million years would I denigrate what the Ford engineers came up with originally.  I guess my point is you can run a relatively high CR on such a motor and street drive it - provided you are willing to run a mixture of race gas.

Bill, I know that Ranchero you speak of and yes it only nade 380 HP - low CR.

I ran this car on a Mustang chassis dyno early on when I was troubleshooting a break-up at 3000 RPM.  At the time it had a Mallory Unilite and switching to the magentic-triggered unit instead solved that problem.  Off idle, it made 490 ft. lbs.  Wasn't really interested in flogging the motor at this stage, so just a quick observation of power level.

I would say I have every bit of 600 HP and the amount of torque is just staggering.  Yes, it's a light car, but you can drive off any corner in 4th gear - from 1000 RPM with nary a stumble.  And that is would I would call streetable.

As I said, the car doesn't overheat, doesn't load up - I had a tunnel-port that was less streetable than this combination.  In fact, car runs exactly the same way each time I drive it.  Idles at 1000 rpm, doesn't run-on - I have not had to adjust anything really in over three years.  Adjusted the valves once and took some slack out of the chain once.

[jayb]

Awesome car.  I agree that keeping the compression ratio up there is important for these engines to make power.  I would even go a little farther, and say that if you move to an EFI system and control fuel and spark more precisely, you can run 12:1 on 92 octane pump gas.  It will depend on the cams of course, but I've been running my SOHC Galaxie on the street with 12.5:1 or higher since 2008, all the time on premium fuel with 10% ethanol right out of the pump in Minnesota.  At the track I throw in 110 octane race fuel and move to a different fuel and timing map in the EFI system to take advantage of more octane, but on the street, where the car is the majority of time, a straight shot of 92 octane is what it gets.

I also agree with Barry that there is absolutely no reason these engines can't be reliable on the street.  At 800-900 HP, my engines are pretty extreme, but they are no trouble on the street provided, of course, that they are built with reliable components.

[bmalone]

Thanks for the comments Jay.  That is interesting to consider; what you propose with the EFI and mapping.  Hmmmm.

I didn't really introduce myself and that was my first post.

I'm Bill Malone from San Diego, also know as bmalone on the FE Engine forum.

[jayb]

Welcome Bill, nice to have you on the board!

[Heo]

Well i have never worked on a SOHC
never actualy seen one live .But there
have been a couple around here even
though i live in midle of nowere.One
in a boat and one in a 68 shelby.
Possibly the same engine in both.
Around how much will a streetabel
SOHC with god quality parts cost
carb to oilpan

[jayb]

Probably figure $25K - $35K, depending on how you build the engine.   This is assuming, of course, that you acquire the parts and assemble the engine yourself.