Ford Y-block cylinder head flow.

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MichaelThompson
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Ford Y-block cylinder head flow.

Post by MichaelThompson »

So gang how do they “stack up”? Yes pun intended. But really let’s discuss how ridiculous the tangent Ford engineers went off at the dawn of their OHV V8 era. Or was it ridiculous? If you listen to pop culture the Y-block is the Rodney Dangerfield of the 50’s Detroit V8’s. It don’t get no respect. But was or is that opinion unfounded? I certainly can look back through old modified sportsman pictures and see plenty of Y-blocks called to action on the short tracks and bull rings all across this fruited plain.

So my question is.....does a sideways intake port make sense? My opinion? Yes but only based only on my own theory. The major port dimension is parallel with the valve seat. I think that probably improves the ability of the port to flow over the valve head especially the short side radius.

I realize in the Y-block has a head bolt in the flow path and maybe the over under makes it hard to balance flow between the two.

Anyhow I’ve always wanted to have this conversation. I have no experience with Y-blocks other than building just one stocker for a ‘55 T-bird.

What are your thoughts?
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Re: Ford Y-block cylinder head flow.

Post by PackardV8 »

That no other engine used it, not even other FoMoCos, is often the best proof of a bad idea.
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MichaelThompson
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Re: Ford Y-block cylinder head flow.

Post by MichaelThompson »

Point taken but what if they built a symmetrical port Y-block head with the intake ports still laying on the major dimension?

Take for example a Cleveland head. Racers used to fill the intake port floors. After that process you sort of have a really wide intake port almost mimicking a Y-block albeit still with a much greater volume and in a raised position.
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Re: Ford Y-block cylinder head flow.

Post by liqu »

I have a set of Y Block Ford heads that flow (intake, high port) 245 @ .550 2.02 valve @ 28"
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Re: Ford Y-block cylinder head flow.

Post by Joe-71 »

The biggest problem with the Y block head is not the over and under ports, but a large portion of the combustion chamber is outside the cylinder bore, and the turbulence involved in flow. The intake valve size is limited or the lift is limited by the cylinder edge. The stock heads have several variations and valve sizes, which were common of the time period, but the later heads with the 1.920/1.510 valves do flow as well as the SBC heads of the era. A stock 113, 471, -G head will flow ~185-189 cfm as cast @.500" lift. I have ported dozens of the different variations of those heads, and 260-265 cfm seems to be about all possible with the upper port, and 258-260 cfm for the lower port. To get to these flow levels, a brass tube may be necessary in the pushrod holes, and a 2.00-2.020" intake valve. The exhausts can be opened up to 1.600", but actually work just as well with 1.550" valve, and flow usually comes in at ~180-190cfm without an exhaust tube. Without breaking into the pushrod tube holes, port flow usually ends up in the 240-260 cfm for the upper ports, and 225-232cfm for the lower ports. That is what I have observed on my flow bench from at least 3 different cylinder head porters from around the USA. My best heads flow 262/260 with a 2.000/1.550" valve. Joe-71
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Re: Ford Y-block cylinder head flow.

Post by MichaelThompson »

Okay guys thanks for your great input and sharing your hands on experiences. So the question still begs. What was Ford thinking here? Their earlier Lincoln V8 circa 1952 had conventional paired intake ports with “stood up” valves and a very interesting combustion chamber which looks to be turbulently active and well researched.

I have read that the “stacked” ports were used to get the largest possible port for a given space. Very curious priority for a sub 300” V8 engine. In fact the very first 239 Y—block had tiny intake ports. On top of that the cylinder head bolt intrudes on the intake port and creates a dog leg situation.

No I don’t know if I agree with the bigger port theory. I think Ford was experimenting with getting flow all the way around the valve not just more to one side as some of the more traditional designs with greater valve angle tend to do. Think of a Chrysler hemi or 23 degree Chevy head. The greater the valve lift the more those ports want to dump on the short side of the intake port while the roof of the port slows down.

In a Y-block I suspect with the 18 degree valve angle and the position of the port that maybe an effort was made to get the intake charge to flow as I mentioned before all the way around the valve thereby increasing low and mid vale lift efficiency.

OR I could be completely full of crap and those early designers were just winging it. Interesting to note though that on a 3 or 4 valve modern head the intake port is usually a modified rectangle laid on it’s side and the flow approaches the valves the same way. I realize that some of that port shape is dictated by the valves being side by side but it seems to me if a vertical rectangular or round intake port worked better they’d have headed in that direction.

Sorry guys just ramblings I know but it’s fun to revisit some of these quirky old ideas like the Heron head etc.

Thanks!
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Re: Ford Y-block cylinder head flow.

Post by BCjohnny »

I have read that the “stacked” ports were used to get the largest possible port for a given space.
I very much doubt it ...... besides it makes little sense

Looking back, in reverse so to speak, it's easy to forget the 'Y' Ford was the replacement for the 'Flathead V8'

The FV8 was engineered within reason to be the cheapest possible way for Ford to put a V8 into it's cars

As it breathed so badly virtually any reasonable ohv design that replaced it would be night and day better, at the least possible premium

As we're guessing as to motive for the 'Y' intake port arrangement I'd aver perceived coring and casting costs for the head, and manifold, were at least as important as anything else ...... and ultimately proved incorrect
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Re: Ford Y-block cylinder head flow.

Post by MichaelThompson »

Thanks fellas, your input is much appreciated.

One further point I’d like to make is I personally never thought of the Ford Y-block as being the cheapest way of getting OHV’s to the market.

The cheapest way would have been a revised Flathead style block that was unskirted and bolted to the current array of transmissions Ford was using at the time.

I believe the lead engineer of the whole Y-block genre’ was a fellow who built his reputation in the heavy truck category.

To me the Y-block cylinder block looks like the forerunner to many later super blocks like the hi-po FE’s the 426 hemi, and the current crop of engines from Detroit. Gen 3, LS/LT, Mod/Coyote.
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Re: Ford Y-block cylinder head flow.

Post by Truckedup »

Ford's first OHV V8 was the 52 Lincoln engine, also used in trucks. I believe it had a deep skirted block but heads with the more common side by side intake ports..?
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Re: Ford Y-block cylinder head flow.

Post by MichaelThompson »

Truckedup wrote: Thu Sep 03, 2020 10:53 am Ford's first OHV V8 was the 52 Lincoln engine, also used in trucks. I believe it had a deep skirted block but heads with the more common side by side intake ports..?
Yes exactly. I have a ‘54 317” truck V8. Tall deck, same bore center as an FE. Similar bell housing pattern that can be modified to work with FE bell housings.

Heads have generous intake ports and raised exhausts.
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Re: Ford Y-block cylinder head flow.

Post by Dan Timberlake »

The 1954 SAE paper has this explanation of the intake port choice.
y-block intake SAE.PNG
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Re: Ford Y-block cylinder head flow.

Post by PackardV8 »

Dan Timberlake wrote: Thu Sep 03, 2020 8:17 pmThe 1954 SAE paper has this explanation of the intake port choice.
Yes, Dan, that's their explanation. I've done a bit of technical writing in which the assignment was to convince readers there were really sound reasons for this bad decision.
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Re: Ford Y-block cylinder head flow.

Post by pdq67 »

Would somebody please post up a picture of the, "better", Y-Block head combustion chamber vs the regular run of the mill production one.

I think it was the '57 supercharged chamber, if not mistaken?

Please post up both of them if you can so we can compare them.

Thanks in advance.

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Re: Ford Y-block cylinder head flow.

Post by Truckedup »

My first car at 16 years old in 1964 was a 56 Ford 292 three speed. Pulled the heads for milling and a valve job. 3/4 Wolverine cam, three 97's and a 57 mechanical advance distributor. I had help doing the work.....It ran good but the 220/283's were hard to beat...
Back then reading in HotRod magazine, a guy was maximum milling Y block heads for more compression. There was a possibility the combustion chamber could distort, probably the quench area.So he drill holes ,tapped, ran in studs to jam against the other side of the water jacket...
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Re: Ford Y-block cylinder head flow.

Post by MichaelThompson »

Here’s a great Y-block story. Many of you may be familiar with Karol Miller.

http://yblockguy.com/articles/KarolMillerStory.html
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