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."

DiLL

Weaker Crank vs steel, heavier Connecting rods, heavier pistons, thin cylinder walls and 113's wont breath.


Hyvinkää, FI

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.



DiLL

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.   

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..


Paul

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.


Hyvinkää, FI

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.

miker
55 bird, 32 cabrio F code
Kent, WA
Tucson, AZ

If displacement is kept the same, as is his plan, then everything else equal, compression will remain the same.


Lawrenceville, GA

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.

DiLL

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.


Lawrenceville, GA