Hi guys, just wanting some input on an estimated HP number for my 272 y block. I will be getting it on a dyno in the next 12 months to get tuned up and get actual numbers but just curious on your thoughts.

It’s in a 59 f100 with t98 4 speed. Only done a couple hundred miles since rebuilt. It feels strong and punchy with the 3.92 gears in the rear

- 272 block bored .020 (275ci)
- Stock 3.30 stroke
- Decked block (pistons level with block)
- CR around 8.5:1

HEADS (ECZ-G)
- SBC 2.02 intake valves
- probably only .005-.010 off the heads to clean them up
- New guide inserts and positive seals
- New valve train 1.54 ratio rockers
- 95lbs valves springs

Cam
- Y270s clay smith from Mummert, 108 LSA, duration 224 IN/EX @.050
- 0.446 IN/EX with 1.54 rockers

Intake/carb
- B intake machined with 2x oval slots
- 2inch 4 hole spacer
- Edelbrock performer 600cfm vac secondary’s

Ignition
- Msd ready to run distributor
- Msd blaster 2 coil
- 8.5mm wires
- New plugs
- All in at 3000 rpm
- Can’t remember the curve but I think I used the light blue and light silver springs and a different stop

Exhaust
- Patriot headers 3inch (not sure about tube size)

Probably left something out.



Thanks, Dennis.

56 F100 - 272 Y Block
NSW, Australia.

Looks like a nice motor.  Back in the day when we street raced Y-Blocks, 272s were some of the best runners.

You picked some good parts  Pretty much what i would have done...

Probably getting close to 1hp/ci with the heads, intake, headers, camshaft, carb.  Engine dyno, or chassis dyno?  Chassis will be a bit less to the wheels.    Joe-JDC

JDC

Is your build hypothetical, or have you actually acquired all of the listed parts for your build? If you are going to use 2.02 intake valves, you may have to notch your cylinders to prevent shrouding/clearance issues. I think the 2.02s would be more suitable for a larger-displacement engine.

Agree , a 1.92 or 1.94 valve will more than supply enough air for a 272

Thanks Phill, that’s good to hear as the whole build I’ve been a bit disappointed that I couldn’t get my hands on a 292. I felt like I’ve been missing out on extra displacement.


RB, thanks. I tried to use the best stuff I could afford. I have other goodies like melling oil pump with heavy duty shaft, tubular push rods, new valve train, ARP rod bolts, ARP main studs, ARP head studs, the pistons are forged (only because they were the only ones they had left).

Joe- thanks, that sounds promising. I think I would like a bit more compression like 9.5:1 but I think I’ll just leave it as it is for now. This is the first engine I have rebuilt and had no idea about compression ratio until I had a lot of the parts already. It will be chassis dyno.
I’m already planning my next Y build. I’m thinking a blown (low boost 5-7 psi) 272 as I already have an old 272 with ecz-a or ecz-c heads. I’m thinking I’ll keep it simple and use the original heads and use oversized exhaust valves, factory cam and just give it a good going through. I just re- read the thread about the twin turbo Y and it got me all excited about boost.


55blacktie- it’s all real. The engine is in my 59 F100 running and driving. The 2.02sbc valves fit good, just had to take .060 off the top of the stem to get them the same length as the factory y valves. Cliff, one of the fellas on here put me onto the 2.02 SBC valves (thanks Cliff). The first machinist did such a bad job that I had no other choice to run over sized intake valves by the time I went to the 2nd shop.


Thanks, Dennis.

56 F100 - 272 Y Block
NSW, Australia.

I’ll venture a guess of 245 HP at the crank. A stock 272 was 182 so a 90 hp gain would be quite an achievement so I’ll say a + 63..not on a chassis dyno. That will be lower.
Don’t let the rear wheel dyno numbers be the know all to end all. Many are disappointed when they see the number. Unless you are building a racing engine, drivability it what its all about and y-blocks have always been very good driving and cruising engines. I can kick mine in the butt and see a true 100 mph but 2200-2500 and the freeway keeps up with any crowd I’m running.

56 Vic, B'Ville 200 MPH Club Member, So Cal.

Good job

I was thinking 250, so we're probably in the ballpark.