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By DiLL - 6 Years Ago
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Has anyone used an EBU 3.10" stroke crank in a 292 Block? Would this crankshaft combined with a 3.875" bore and ported 113 heads with 2.02" I and 1.6" E valves be a good candidate for a road race application? The block would still be 292 cubic inches just more "over square."
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By LordMrFord - 6 Years Ago
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Weaker Crank vs steel, heavier Connecting rods, heavier pistons, thin cylinder walls and 113's wont breath.
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By DiLL - 6 Years Ago
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Not all 292 cranks are steel. C1TE is, ECZ / EBU is not. I’ve read (forum below) about cast being lighter and able to rev faster than steel cranks. Steel is only needed for blown apps?? I plan on lightening The entire rotating assembly as well. https://www.jalopyjournal.com/forum/threads/292-y-block-steel-crank.419454/
Tim McMaster offset ground an EBU crank to a 3.3 and had 1.888” Honda sized con rods (lighter/less friction). He also has said that y blocks can easily be built to 7000+ rpm (sustainable rpm for a road course type application😁 I’d love to find out!)
Guys are porting 113’s and making 230+ cfm 350hp+ potential. especially when used with the JM aluminum intake.
I understand that the bore size and wall thickness is limited. However, this block has been sonic checked and is good for the overbore.
I’ve done a ton of reading and haven’t come across much about combos with these 3.10” crankshafts? I want to strictly race this car on a road course style application. I know these engines can make tq #’s high into the rev range. Would sacrificing some tq with a shorter stroke enable a higher rpm and high hp capable y block? Could this be the better combo for a road course style engine?
I want to use as many decade correct parts as possible but would like it to be able to withstand the abuse.
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By 1960fordf350 - 6 Years Ago
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I'm just wondering which pistons your using. Aren't you lowering the compression ratio by de-stroking? Or are you using oversize 256 pistons? Compression height is different than the 272/ 292 pistons.
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By PF Arcand - 6 Years Ago
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I seem to recall that there was an engine like that done by someone on this site, but I believe it was done to make class in Dry Lake racing.. And not sure why you would want to lose making torque at a more reasonable rpm? Properly cammed and so on, Y-Blocks can make good torque. Apparently for one thing, there's some evidence that the over & under intake port design leans itself to a good torque curve, probably due to the intake manifold runners being more equal in length than other conventional V-8 engines. Engines built by John Mummert Machine & Ted Eaton Balancing have shown excellent torque ratings.. I suggest for example, linking to Mummert's site from here & look up his Dyno test of a 337" streetable engine..
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By LordMrFord - 6 Years Ago
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Highest rpm what we made is 9178 when I forgot turn on the limiter.
Steel crank, 292+030, light rods+ pistons.
Light weight piston pins might damaged then but we are not sure was it high rpm or high boost.
Usually rpm's kills engine faster than anything else.
I doubt you can compensate missing cubic inches with higher rpm's but who knows.
Fast revving Y-Block sure sounds nice. 
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By miker - 6 Years Ago
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I’d suggest you do a little research under “Doane Spencer Thunderbird”. The original engine/clone car ended up in SoCal a few years back, and there was even a posting on here about the (then) new owner modifying a set of Mummert’s aluminum heads to look like the stock heads. This was the clone of the original, using the engine suspension, etc. in a different body. Spencer’s original car had all this removed, and new suspension and drivetrain fitted. It’s a much more complicated story than this.
I don’t recall which castings were in that car, but I recall hearing the exhaust valves had been relocated. Kirk White had a good run down on it and the engine when he owned it, but I haven’t seen it since he sold the car.
I’ve got a couple sets of Mummert’s ported heads, 113’s and 471’s, and a set of his aluminum heads. Destroking a y block and and running the revs up is an interesting idea, but even with good heads, intake, etc. getting the airflow is going to be tough. Cam selection, valve springs, etc. for the wide range of rpm and extended usage on a road course is also going to be a concern.
It’s worth noting when Spencer decided to update his 55 bird, engine, front suspension, and an IRS of his own design, he built a 302 SBF. He had extensive experience with them by then in Sunbeam Tigers and Cobras. But that’s another story in the legend.
Both the original and the clone sold at about the same time, you should find something on both of them.
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By charliemccraney - 6 Years Ago
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1960fordf350 (4/29/2018)
I'm just wondering which pistons your using. Aren't you lowering the compression ratio by de-stroking? Or are you using oversize 256 pistons? Compression height is different than the 272/ 292 pistons.
If displacement is kept the same, as is his plan, then everything else equal, compression will remain the same.
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By DiLL - 6 Years Ago
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I’m hoping to find some Forged scruby 283 pistons (ultimately may have to have the pistons custom made) I want to get the compression as high as I can (read that these engines can handle around 12:1 with the iron heads). Thanks for the info Miker I shall look into it! LORDMRFORD I’m sure it sounded splendid haha! PF Arcand i don’t necessarily want to lose the torque just want to make it higher in the rpm band. I too have read the stacked port design was great for this specifically which is why I was curious if anyone has tested this or done it with the shorter stroke.
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By charliemccraney - 6 Years Ago
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If you want 12:1 with only 292ci, then you will need custom pistons because you will need domes that fit the head. Also, if you go with a 283 piston,you would have to find just the right length rods so that the piston ends up a pretty close to flush with the deck - that could require custom rods.
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By Joe-JDC - 6 Years Ago
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I am going to go against the grain here and say that for road racing, I would build as much torque as possible, and keep the velocity through the heads as fast as possible everywhere on the road course, and keep the rpms down in a manageable band where you can use the torque to your advantage. Then gear the rear differential to make use of the added torque. In my younger life, I worked with a shop that did stock car racing, and we found that coming off turns and corners with torque was a lot quicker than trying to play catch up in the straits with higher rpms. I would much rather have a Y block that would make 30 more lbft torque in the middle of the rpm range with a road race engine than having a few more horsepower in the last 500 rpms of the tachometer. JMO, but to move out of curves quickly, you need torque. I would use the longest stroke possible, with the longest rod possible, and the shortest piston pin height to get the cubic inches needed for the class you plan on racing. This is strictly for a road race build where you have hills, curves, and cubic inch limit. Joe-JDC
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By Cliff - 6 Years Ago
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Joe knows just what he's talking about, if you will look at the racing forum you will see my current dragster build (iron heads), I looked at the short stroke and large bore but I was not interested in turning a Y Block Ford into a sbc chv, I see no advantage to the large bore and short stroke other than to be able to fit a larger set of valves.
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By DiLL - 6 Years Ago
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Joe-JDC that is exactly what I wanted to know, Thanks a lot! Would you still consider an offset ground cast crank to hold up against road race/extended rpm type abuse? Or should I look for steel? Also, should I still attempt the bigger bore (3.875”) to unshroud the bigger 2.02” 113’s valve? Or.... keep the 3.81” bore I have and use an original set of ECZ-G’s ported (unposted)with 1.927” I and 1.6” E..?if you don’t mind, what would a typical cam spec look like for a stock car engine of that time?
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By Ted - 6 Years Ago
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I’m with Joe on concentrating on torque production rather than peak horsepower numbers. Unless you are restrained by a given set of rules on the cubic inch limitations, then bigger is typically always better. If hitting the typical limit of 1.5 HP/cubic inches for a normal high performance build, then making the engine larger simply results in larger power numbers. I do deal with engines that are limited by the rules on the cubic inches and in those cases, the engines are made to be within a couple of cubic inches of the maximum allowed to permit making as much power as possible and still be ‘legal’.
I do a large number of offset ground crankshafts for different engines and a good balance job goes a long way in insuring the durability of those crankshafts. Crankshafts can be offset ground for less or more stroke depending upon what’s required. The problem with offset grinding for more stroke is that the amount of offset between the main and rod journals is decreased (less actual cross-section of material) and that potentially weakens the crankshaft at the various filets with crankshaft flex being the root of the problem. On my end, I’ll offset grind an oem cast 312 crankshaft with a 2” rod journal while also turning the mains down to a 292 journal size. Zero issues to date doing this but FoMoCo didn’t do it for a reason and that reason centers around the amount of offset between the rod and main journals.
There were some basic engineering rules back in the day and maintaining a given amount of offset in the journals was a standard practice. When the 312 Y-Block was introduced, the crankshaft received an automatic increase in the main journal size to maintain that journal ‘offset’ value. GM broke that rule in 1967 with the introduction of the 350 and paid dearly with that with a number of broken crankshafts that year. Comes 1968, the GM 350 engine has the larger main journals and the crankshaft breakage problem is resolved. GM introduces the 400 SBC in 1970 and with lessons learned from the 1967 experience, the main journal is once again increased to keep the journal offsets at that minimum required value. With the advent of better materials, journal offset amounts have since allowed to be decreased thus allowing for additional stroke without increasing the rod and/or main journal size in which to compensate. Racers being the innovators that they are, did take the 400 crankshafts, turn the mains down to the 350 journal sizes, and shoved them in the 350 blocks for a cheap 383” stroker back in the day. Those crankshafts are now readily available as an aftermarket piece with zero durability issues using more modern materials.
For Y's in general, I try to limit bore sizes to 3.860” and only go that far after sonic testing the cylinder walls. Core shift in the block castings is an issue with most engines. Be cautious in going the larger intake valve route as air flow can actually diminish with the larger sized valves due to shrouding at the edge of the cylinder walls.
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By Joe-JDC - 6 Years Ago
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DiLL (4/30/2018)
Joe-JDC that is exactly what I wanted to know, Thanks a lot! Would you still consider an offset ground cast crank to hold up against road race/extended rpm type abuse? Or should I look for steel? Also, should I still attempt the bigger bore (3.875”) to unshroud the bigger 2.02” 113’s valve? Or.... keep the 3.81” bore I have and use an original set of ECZ-G’s ported (unposted)with 1.927” I and 1.6” E..?if you don’t mind, what would a typical cam spec look like for a stock car engine of that time?
Like Ted mentioned, the offset ground crankshafts have had zero trouble when using the 2.000" journal. Also, I would stay with the best torque plate honed small bore possible. I prefer to keep the intake valves as small as possible to get the flow needed to save on weight, and unshrouded. Just last year I ported a set of big and little -G heads with 1.925/1.510" valves for a forum member, and was able to get 226/235 cfm on the intakes, and 167/170 cfm on the exhaust. I just completed a set of 113 heads for myself with 2.000/1.550" valves that flow 256/260, and 170/170 cfm. These heads will go on a smaller bore, hopefully in the 3.830" range. Camshaft selection depends on a lot of variables, like car weight, gear ratios, transmission type, road speed, tire sizes. Ted, or John, or one of the vendors may be able to help with camshaft selection when you know all these factors. Joe-JDC
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By NoShortcuts - 6 Years Ago
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Dill. The thinking for building an appropriate y-block engine for road racing seems to have been very well explored, laid-out, and discussed by knowledgeable Forum members on this thread.
Coupled with this are your earlier statements in this thread:
1) 'I want to use as many decade correct parts as possible but would like it to be able to withstand the abuse.'
2) 'I want to strictly race this car on a road course style application.'
Therefore the question:
Besides the engine, what else is needed to create a successfully competitive road course vehicle?
I'm sure there are numerous considerations having to do with the chassis, such as suspension, steering, and braking.
Yes, but coming back to optimizing the output of the engine, the key would seem to be staying in the upper area of the engine's torque curve. The transmission provides THE means to do that.
I can't think of a period correct Ford 3 speed or 3 speed w/ overdrive transmission that you should consider for a road race course.
Sooo . . . Consider bending your thinking a bit and compromising by selecting a modern 6 speed transmission for the engine and chassis that you are going to use that will connect with your y-block.
I'm not one to advise you on what ratios would be optimum for the engine build you're considering, the vehicle weight you will be working with, or the tire size you might select, but I'm suggesting that to take advantage of wherever the upper torque curve is for the engine you build, you want the transmission to allow you to stay in that engine speed area while you traverse the road course. A six speed transmission may be exactly what is called for to make your vehicle perform competitively. Some six speed trannys have double overdrive gears in them!
Click the link below for sample offering from Modern Driveline in the TREMEC line . . .
http://transmission.moderndriveline.com/speed/pc/viewcategories.asp?SFID=7%7C%7C1&SFNAME=Application%7C%7CPattern&SFVID=42%7C%7C2&SFVALUE=Ford%7C%7C6+speed&SFCount=1&page=0&pageStyle=p&idcategory=3&VS1=0
IF you don't need that much gear ratio flexibility, you could look at a 5 speed transmission. Click the link below for sample offering from Modern Driveline again in the TREMEC line . . .
http://transmission.moderndriveline.com/speed/pc/viewcategories.asp?SFID=7%7C%7C1&SFNAME=Application%7C%7CPattern&SFVID=42%7C%7C1&SFVALUE=Ford%7C%7C5+speed&SFCount=1&page=0&pageStyle=p&idcategory=3&VS1=0
Final drive ratios will likely end up being what drives your selection of a particular 5 or 6 speed box. Hope this helps you with your project!
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By miker - 6 Years Ago
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If you don’t mind my asking, what sort of road course racing are you looking at? Vintage, track days, running the canyons for fun? What kind of chassis is it going in?
Here’s a link to Spencer’s bird. It doesn’t include running the original at Bonneville.
https://www.hemmings.com/blog/2013/08/09/a-bird-in-the-hand-both-doane-spencer-thunderbirds-head-to-auction/
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By John Mummert - 6 Years Ago
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Keep the valve train in mind. Getting enough spring on a flat tappet to run continuously at 7500rpm is another story much less 8000. Lobe dynamics, valve and retainer weight etc. are gonna matter. 8000 is no problem with TI valves, but pricey.
The block is too tall to consider destroking one. Rod choices and piston compression height just get to weird. A stock 292 has a 3.3" stroke and a 6.324" long rod, thats about where current nascars are today. Only problem is 1.785" compression height for the 292 will have weight and equilibrium problems vs 1.1" or less compression ht. for a current nascar. Lengthening the rods will hurt the low end and mid range in a small displacement motor.
Build a relatively conventional bottom end 2.1" or 2.0" pin 3.3" to 3.44" stroke . Keep the rev band between 7000-7300. Save money to get the top weight off the motor to lower your CG, heads, intake, carburetor, timing cover should be aluminum, kill'em with corner speed just as effective as straight aways.
Make sure you have close ratio, gear box,, rpm climb in the down shifts will eat a valve train alive
Rotating mass in the driveline is big, accelerates quicker, slows down quicker, 9" is not necessarily the hot ticket.
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By Small block - 6 Years Ago
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From My experience the only time you would want to use a short stroke large bore is in a class were the engine size is limited and your going for a High Horsepower per Cubic inch. Like what was done in the early Trans am Racing small engine big bore short stroke and rev the heck out of it!
Big numbers were seen at high RPM but they were hard on parts!
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By 57ranchero - 5 Years Ago
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The quick short answer: the engine should rev up faster but there are other considerations as mentioned in the other responses. Loss of
torque from the engine can be compensated for by the transmission, differential and tires. And of course where the rubber meets the
road is the real key.
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