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By dennis22 - 3 Years Ago
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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.
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By Florida_Phil - 3 Years Ago
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Looks like a nice motor. Back in the day when we street raced Y-Blocks, 272s were some of the best runners.
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By RB - 3 Years Ago
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You picked some good parts Pretty much what i would have done...
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By Joe-JDC - 3 Years Ago
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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
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By 55blacktie - 3 Years Ago
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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.
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By RB - 3 Years Ago
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Agree , a 1.92 or 1.94 valve will more than supply enough air for a 272
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By dennis22 - 3 Years Ago
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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.
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By DryLakesRacer - 3 Years Ago
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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.
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By Cliff - 3 Years Ago
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Good job
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By 55blacktie - 3 Years Ago
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I was thinking 250, so we're probably in the ballpark.
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By dennis22 - 3 Years Ago
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Drylakes, blacktie- thanks for that estimation. I’ll be sure to post the results. I just have to find a tuner with experience tuning carburetors on the dyno, not too many here in Australia unless you’re in the know.
Cliff- thanks mate, so happy with the heads now!
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By dennis22 - 3 Years Ago
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With the engine as is, what would you estimate the safe max rpm? After a bit of reading it seems like 5000-5500rpm max is the limit for safety. What are the limiting factors? Is it the just weight of the rotational mass and the lack of roller rockers, roller cam for the Y block?
What is likely to happen if revved up to 6000rpm frequently? (Don’t worry, I keep it below 5000rpm)
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By Ted - 3 Years Ago
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My two cents worth here.
The bottom end is more than capable of running up to 6500 rpm when all is correct in that area but head/intake flow and valve train will be your limiting factors. Dead stock 2V engines were typically peaked out at 4500 rpm and would eventually go to 5000 rpm if just staying in the throttle before valve float set in. In your case, I suspect that your engine will be peaking at 5400-5500 rpm with the camshaft you have selected along with the other parts. As a general rule, the 2.02 inch intake valves are not as good at producing low end power in those small bores as the 1.92-1.95” valves but can understand using the larger valves when trying to salvage the existing valve seats. Intake valve shrouding tends to be more of a power deterrent than whatever is gained by increasing the actual valve size and especially when dealing with the smaller 272 bore sizes.
While the Carter and Edelbrock carbs can be counted on in cranking up and idling just fine, they can be finicky in getting the tune just right for making those peak power numbers. You will need a collection of jets and metering rods on hand to make adjustments during the dyno session. Keep in mind that those carburetors are fuel pressure sensitive and may require some float adjustments to compensate for your particular fuel pressure. Having a wide band oxygen sensor hooked up will speed up the tune up process versus just reading the spark plugs.
Consider removing some weight from the secondary counter balance weights to allow the secondaries to open a little earlier. I do that using a scale to measure first the overall weight of the counter balance weights and then take the same amount off of each weight. If you have one of the newer Edelbrock AVS carburetors, those do have externally adjustable secondaries and eliminates the need to pull the cover off of the carb to manually modify the secondary opening rate.
My estimate for rear wheel horsepower will be 200-210.
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By dennis22 - 3 Years Ago
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Thanks Ted, that’s some good info!
I’ll keep in mind valve float up around 5500.
The edlebrock carb is a new performer 14063. It seem pretty good but I wouldn’t mind some o2 sensors to get it right. I’ll make sure I’ve got a handful of bits and pieces for tuning. I’ll have a look at the secondary’s weights, thanks for that tip.
It might be a while until dyno day but I’ll post up the results.
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By Gene Purser - 3 Years Ago
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dennis22 (4/7/2021)
With the engine as is, what would you estimate the safe max rpm? After a bit of reading it seems like 5000-5500rpm max is the limit for safety. What are the limiting factors? Is it the just weight of the rotational mass and the lack of roller rockers, roller cam for the Y block? What is likely to happen if revved up to 6000rpm frequently? (Don’t worry, I keep it below 5000rpm)
I built a 312 back in the '80s. A trusted old Ford mechanic told me not to rev it over 5500. He said the HP engines had a different valve keeper and that the standard version were prone to shake loose and drop a valve at higher RPM. I'm not sure if the 2x4 version had the HP keepers, or if it was the F engine. Hopefully, someone can add some info.
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By Hoosier Hurricane - 3 Years Ago
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The dual four engines also had the one piece retainers like the blown engines.
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By PF Arcand - 3 Years Ago
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Just for clarifiction going back on these postings.. A regular stock 272 engine, prior to 1957, was about 167 h.p. not 182 as stated. That was only found in the special 4 Bbl dual exhaust versions..
Further; As this particular engine was only bored 0.020" over, & assuming that a particular 272 block doesn't have a serious core shift in it, what is a safe overbore allowing for say one more 0.20" overbore if needed ?..
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By Ted - 3 Years Ago
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PF Arcand (4/10/2021)
Just for clarification going back on these postings.. A regular stock 272 engine, prior to 1957, was about 167 h.p. not 182 as stated. That was only found in the special 4 Bbl dual exhaust versions..
Further; As this particular engine was only bored 0.020" over, & assuming that a particular 272 block doesn't have a serious core shift in it, what is a safe overbore allowing for say one more 0.20" overbore if needed ?..
Almost all Ford Y engines are good for being ‘safely’ bored to 0.060” over. There are exceptions to this but sonic testing does separate out those blocks that have excessive core shift. While some of those blocks cannot be successfully over bored without offset boring the cylinders, there are those on the other end of the scale that can be bored much more than 0.060” over. I have taken a fair number of 292 blocks that had good sonic test numbers to 0.110” over and made them into high horsepower producers.
There are a large number of 272 engines out there that have been bored 0.125” over to make them into standard bore 292’s. Fred Jones Engines in Oklahoma City (authorized Ford rebuilder) did this to a large number of 272 engines and made them into 292 engines. These engines worked well with stock compression ratios but when measuring them for cylinder wall thickness, they are poor candidates for a performance build.
My ’55 Customline still has the original 272. At 112K miles I was into the engine and bored it to 0.020” over simply because I was in there and wanted it fixed for the long haul. Cylinder wall wear was minimal and could have gotten by with just a re-ring job. I did sonic test that block at the time and it was a candidate for a +060 over 312 bore or more but being as I’m a believer in only boring out the engines only just enough to clean up the cylinders, 0.020” over it was. It was upgraded with the ECZ-B 4V intake and Isky E4 camshaft along with a balance job at the time and still runs good today with over 300K miles on the car now. The crankshaft in that engine is still STD/STD and the oil pressure is still very good at all rpm. While I did not dyno test this engine, I always felt it was in the 200-205 HP range with its original 272 small valved heads
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By BamaBob - 3 Years Ago
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Ted, in regard to what these engines can stand, would a 1955 3-speed Fordomatic be adequate for a mildly upgraded 312(4bbl, mild cam upgrade, G heads, 1.54 rockers)? If not, what would you recommend? Thanks.
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By KULTULZ - 3 Years Ago
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... would a 1955 3-speed Fordomatic be adequate for a mildly upgraded 312(4bbl,
IMO - 
That would all depend on how hard you want to run it. At the least, a 56 coolant cooled trans or if it is going to get serious street use, either an FMX or possibly C4 upgrade. Is the car remaining stock other that the engine upgrade?
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By BamaBob - 3 Years Ago
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It would not be run hard, but would be somewhat of a daily driver. I had thought of a 56 medium case transmission, but I already have the rebuilt 55 and not the 56. Economics comes into play here, but I don't want to make a mistake now that I will regret later if I can prevent it! If I can find a 56 at a reasonable cost, I might still go that route. Otherwise, it will be mostly stock with maybe disc brakes added. Thanks for your reply.
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By RB - 3 Years Ago
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Your 55 trans should be able to handle the torque of the 272 no problem.. Ask all those guys who did reverse to low shifts to get the tires spinning back in the day.. . I probably have a stock 56 that will be removed soon.. Where are u located?
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By KULTULZ - 3 Years Ago
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Otherwise, it will be mostly stock with maybe disc brakes added.
Hey, I understand. They used to call me JUNKYARD DOG.
The trouble with the pre-mid 56 trans is it's air cooled. You have to watch the TRANS TEMP, especially if you clean the carb out occasionally. And the TV linkage has to be adjusted correctly, bands adjusted, yada yada yada..
Hope you have good luck with it.
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By BamaBob - 3 Years Ago
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RB (4/11/2021)
Your 55 trans should be able to handle the torque of the 272 no problem.. Ask all those guys who did reverse to low shifts to get the tires spinning back in the day.. . I probably have a stock 56 that will be removed soon.. Where are u located?
I am located in east central Alabama. Is your 56 transmission a medium case water cooled unit?
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