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By bergmanj - 9 Years Ago
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Folks,
Does anyone know or has tried to open-up the ECG-D intake valve openings / seats to accept the 1.92" intake valves. These two heads (ECZ-G & ECG-D) appear to have very similarly sized combustion chanbers when looking at them on the bench, only major difference appearing to be intake valve sizes. Ted? Anyone else?
Regards, JLB
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By charliemccraney - 9 Years Ago
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They are not even close. ECG-D is 7.6:1 on a 272. ECZ-G is 8.6:1 on a 272. That requires about 10cc difference.
What usually limits valve sizing is the relation of the spark plug, and the other valve. The difference between the valves is .140" so that is about 1/16" increase of the radius of the valve. Does that look like it will fit?
http://ford-y-block.com/cylinderheadchart.htm
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By Ted - 9 Years Ago
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Having an abundance of big valve Y heads in which to work with, I don’t have much experience modifying the smaller intake valved heads to accommodate the 1.92” or larger valves. As Charlie brings up, it would be prudent to first perform some combustion chamber volume checks on both heads and confirm the actual cc’s. I did look at my notes and the perimeter measurements of the ECZ-G and ECG-D combustion chambers are very similar but it will still take a cc measurement to confirm that the chamber volumes themselves are similar.
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By bergmanj - 9 Years Ago
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Charlie,
Side-by-side, with loose valves, the 1.92" valves almost completely seat "as-is" into the smaller-valved heads; there also seems to be plenty of clearance between exhaust and intake with the larger valves. So, I don't know what to make of your opposite opinions between you and Ted. And spark-plug clearances look good too, even with the bigger valves.
Maybe my question should be: Is there plenty of casting material around the intake valves to even consider the increase in seat sizing?
Ted, I do not have shop equipment to check conbustion chamber CC's; any other ideas for how to check the differences?
Regards, JLB
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By charliemccraney - 9 Years Ago
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We don't seem to have opposite opinions. Both of our comments boil down to we're not absolutely sure and you will need to check.
If you have fitted a valve and can see that there will be no issues with the dimensions, then it will work in that regard. I don't know about material for cutting seats.
To compare combustion chamber size, you simply need to devise some way to compare the volume of one head to another. The easy and most accurate way, most machine shops offer ccing service. Take both heads and a set of good valves for each, pay a small fee, and they will measure and tell you.
A cheaper, less accurate way, get a measuring cup with the smallest graduations you can find and see how much water you can fill into each chamber.
An even less accurate way, set the head up on a bench, fill the chamber with water, open a valve and let it drain into a glass. Mark the level with a marker. Empty the glass, do the same with the other head. With this method, you get a direct comparison, but no idea of the actual volume.
No idea if these will actually work, haven't tried it.
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By bergmanj - 9 Years Ago
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Charlie,
Thanks for the reply. I'll wait for a while to see if Ted or others chime-in too.
Regards, JLB
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By PF Arcand - 9 Years Ago
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You didn't say what engine you have in mind for the heads, but if you already have "G" heads, why not just use them and save the time & expense. Also, the ports in the 55-272 heads are likely smaller, ok at lower RPMs but not in the higher ranges. And, if you grind & fit the 1.92" valves you will likely need to port just behind the seats to get any net benefit.. It's your call..
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By Ted - 9 Years Ago
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Performing cc measurements on the combustion chambers is a basic blueprint activity. The most basic cc measurements will be accurate within 2/10ths of a cc. A cc buret is the standard measuring device and almost any liquid can be used for the measurement. Be aware that the cc measurement needs to be performed with the same heat range spark plug you plan on running for accuracy purposes.
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By bergmanj - 9 Years Ago
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Folks,
ECZ-G heads are badly rusted in some intake & exhaust ports, ECG-D heads are in good shape; just trying to take advantage of "best of both worlds", so to speak, & thought it might be interesting to try.
Application is 272 or 292 block previously bored to its present 297 CID size.
Am slowly building a replacement engine for the poor / existing 272 in my 55 Crown. Just thought that I'd try to "heat it up" a little bit by increasing flow, compression, & using '57 312 cam.
Look, I'm a "home wrencher" with just enough knowledge on the y-block to sometimes be "dangerous" to self and parts (have re-built 5 of them of various sizes including a stock 312 over the years) - which is why I'm soliciting advice here from you experts. Am retired, on fixed income, not wealthy by any means, and can't afford to make any major, costly mistakes; yet; want to "play" a bit. Besides, I really like the sound of a slightly hot y-block: No better sound than the 1-3-4-8-6-3-7-2 lope.
Thanks for the present and any future suggestions.
Any more advice will be taken gratefully.
Regards, JLB
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By charliemccraney - 9 Years Ago
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Which heads are currently, or most recently have been, on the 297?
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By bergmanj - 9 Years Ago
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Charlie,
The ECG-D heads were on that 297 engine. It was a truck engine that had been "professionally" rebuilt (very poorly! - unmatched replacement pistons, varying piston heights, problems with rod bearings, etc.). Got it "cheap" because owner couldn't make it run right (barely at all). The 1957 312 with ECZ-G heads & factory "hot" cam was a 4-decades-old+ rebuild of mine which (unfortunately), through several employment moves (very long story), was left uncared-for. I intend to ressurect that one too, "in the future".
Regards, JLB
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By charliemccraney - 9 Years Ago
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That's good. That means you can squeeze out more power than you had with either set of heads.
Are the ECZ-G heads so bad that they simply cannot be used? They are the way to go if they are salvageable.
Domed pistons can be used to increase compression for the ECG-D heads. While they are more expensive, the difference versus a set of flat tops may be less than purchasing another set of heads.
If you have a die grinder, or even a dremel, you can do a gasket match and port / bowl cleanup at home.
Regarding the valves, as Paul pointed out, even if you fit the larger valves, they are still smaller port heads and even with the bigger valve, you may not realize the benefit of a bigger valve. Other issues arise when fitting bigger valves as well. For instance, even though there may be room to fit the valve, the proximity to the chamber wall and spark plug can restrict flow, possibly making it worse than it was with the smaller valve.
This is an area where it would be wise to take the heads to someone local with professional porting experience, and give them some cash for advice. While no one can predict exactly what will happen without actual R&D, someone with decades of experience porting can look at it and give you a pretty good idea what will happen with a bigger valve and maybe even tell you what you need to do for the best chance that it will work.
To show you what I mean in terms of valve size, the results of cylinder head testing is in the following link. Two pair of C0AE heads were tested, one set with stock valves and lower compression and the other with larger valves and higher compression. The lower compression, stock valve set produced more power.
One of each configuration is not statistically significant so it does not guarantee that larger valves equals less power with those castings. However, it does illustrate that for whatever reason, bigger valves are not always better.
http://forums.y-blocksforever.com/Topic61587.aspx
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By bergmanj - 9 Years Ago
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Charlie,
I've been to that link before when at the local Library; but, I have a very difficult time following links here at home on a very slow (14.4K???), unreliable dial-up internet connection: It can take me up to 1/2 hr. just to get logged-on!! I really appreciate the responses, but, unfortunately, need to keep them limited to text only, if at all possible. I've been on here for almost an hour now just reading your last post, and responding. Very frustrating at this end.
ECZ-G heads are still servicable; but, not in the budget right now. ECG-D heads are in good shape; but, need some valve work: Hence my question about increasing valve size: that's in the budget, and do-able right now; IF there's enough mateial around the seats, and of some credible benefit.
We don't have anyone around here with Y-block head-porting experience. Yes, I've looked at John Mummerts site for some of his porting information.
Budget for different pistons is being saved for the eventual 312 rebuild.
This (now) 297 block had two weight mismatched replacement pistons which were not even intalled at opposite strokes for balancing purposes. I have balanced all wrist pins, pistons, rod tops & bottoms to within 1/10 gram of each other, and had the block decked to zero (to maintain proper quench with the newer composite gaskets at 0.045" crush). The crank is now overbalanced; but, as Ted's info. on his website indicates "its better to be overbalanced, than underbalanced".
Any other comments?? I may just elect to use the ECG-D heads "as-is"; but, my insatiable curiosity still really want to try enlarging the intake valves.
Regards, JLB
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By charliemccraney - 9 Years Ago
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Regarding porting advice, you don't need anyone with Y-Block experience. You only need to be sure that you are getting the advice from someone who has done porting for years. It doesn't matter what the head is. They just need to be able to see it to understand exactly what you are working with. It can't hurt, if there is anyone near you with any kind of professional porting experience, it will be worth the time and a few greenbacks for their advice.
Without knowing or without recommendation by a pro and with limited funds, I would just leave the valves stock and do basic port clean up, gasket matching and bowl work. Easy to do yourself, at home.
This is a copy and paste of the chart in that thread. Cylinder Head | Peak HP | Peak Torque | Comp Ratio | Ported | Mummert Aluminum | 377 | 368 | 9.8:1 | Yes | Mummert Aluminum | 354 | 356 | 9.8:1 | No | 113 | 333 | 350 | 9.2:1 | Yes | G | 328 | 350 | 9.4:1 | Yes | G | 324 | 349 | 10.6:1 | Yes | G | 304 | 337 | 9.6:1 | Yes | G | 302 | 337 | 9.2:1 | Yes | G - stock | 290 | 344 | 9.2:1 | No | 471 | 296 | 332 | 8.3:1 | Yes | ECZ-C – stock | 288 | 336 | 9.0:1 | No | ECZ-C – stock | 280 | 335 | 8.6:1 | No | ECZ-C – stock | 273 | 330 | 8.1:1 | No | ECZ-C after milling | 295 | 339 | 9.0:1 | Yes | ECZ-C before milling | 290 | 334 | 8.4:1 | Yes | C1TE-D after milling | 297 | 337 | 9.0:1 | Yes | C1TE-D before milling | 295 | 335 | 8.4:1 | Yes | COAE-A - stock | 283 | 332 | 8.7:1 | No | COAE-A w/larger valves | 273 | 328 | 8.9:1 | No |
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By CK - 9 Years Ago
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Just increase the lift a little more than what you would with 1.92"
Apparently the Y block will allow .500" lift with a zero decked block.
Bigger lift cam and high ratio rockers. There are calculators which tell you flow for valve size and lift and it might work out for the revs you want.
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By bergmanj - 9 Years Ago
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Folks, I finally got a chance to "cc" the ECG-D head; didn't have a calibrated syringe, but measured the water mass equivalent as being 73 grams. Seeing as 1 gram of water at Standard Temperature and Pressure IS 1cc, my conclusion is that I measured 73cc's. However, in checking the 1.000 factory machining reference bosses at 0.985", it shows that this head has been cut by 0.015", already. I'm not sure what the equivalent cc's are for this size cut; so, not sure what to add for cc's for standard chamber size. Perhaps that could be extrapolated from Ted's head gasket equivalency cc table. I don't have time to do that right now; but, at least there is the basis for chamber siaes on this ECG-D - design head for us as a future reference.
Regards, JLB
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By Ted - 9 Years Ago
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bergmanj (11/1/2016)
Folks, I finally got a chance to "cc" the ECG-D head; didn't have a calibrated syringe, but measured the water mass equivalent as being 73 grams. Seeing as 1 gram of water at Standard Temperature and Pressure IS 1cc, my conclusion is that I measured 73cc's. However, in checking the 1.000 factory machining reference bosses at 0.985", it shows that this head has been cut by 0.015", already. I'm not sure what the equivalent cc's are for this size cut; so, not sure what to add for cc's for standard chamber size. Perhaps that could be extrapolated from Ted's head gasket equivalency cc table. I don't have time to do that right now; but, at least there is the basis for chamber siaes on this ECG-D - design head for us as a future reference.
The ECG-D heads have a combustion chamber perimeter measurement of 10.98” which breaks down as a 0.0064” cut required for each single cc reduction. Assuming the heads have been cut 0.015”, then that reduced the chamber volume ~2.3cc’s.
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By bergmanj - 9 Years Ago
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Ted, Thanks for the additional info. It should be useful in the future. For now, I'm still "considering" my proposal; but, this thread is now on my "back-burner".
Regards, JLB
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By 30 coupe - 9 Years Ago
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for the rusty heads, have them shot -peened , or shot "blasted" at a machine shop. cost is not that bad and they come back looking like new, unless badly pitted from rust. either way they will look like a new casting
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