New guy here.  Fortunate enough to have a small shop in my backyard with good but old equipment.  In my retirement, I do modest street rod engines mainly the older stuff todays shops don't want to bother with, ie. flathead V-8's & V-12's, early hemi's, 383 Mopars etc, along with the requisite SB and BB chevys.  Now....need some info/advice.

My current engine is a 292 Y block.  Have .040 over SP cast flat top pistons.  I'll do the deck close to 0 with a BHJ fixture any my WVN broach, target static compression is 9.0.  Heads are ECZC which, according to my research on this and other sites, are good for smaller chambers.?  It needs new valves.  I can get the 1.920 valves for only slightly more than the 1.780 valves it has.  My inclination is to do it (we've always been told size matters) and leave the exhaust 1.510 due to the smaller chamber.  I would open up the valve pocket with a 75* hog slightly and finish with a 60-45-30 seat.  It would cost slightly more in machine work for the owner, so my question is.... is this the right thing to do for the engine and the owner?  He is planning on using an aftermarket cam in the 268-270 adv. range with @.450 lift and a 4V carb.  Going in a mid 50"s pick up and will be a moderate driver/ streeter.  Sorry for being so long winded.  All opinions/reccomendations appreciated.

Thanks,

Warren

Welcome to the site Warren, I'll let the engine experts ( Ted or John or Tim) have the final word on this, but in my opinon a good set of G heads would be a better bet. They have the big valves already and for the additional machine work that you are talking about, I'm sure that you could pick up a set.

Glen Henderson



Freedom is not Free

Letohatchee, AL

Without more displacement or dome pistons, I don't think you'll reach a true 9:1. With the G heads, you'll be around 8.75. With the C's I think it'll be around 8.15.


Lawrenceville, GA

You can cut the heads out as you have mentioned, it's done all the time, but if you are going for the best you can get do as Glenn said and find a set of "G" heads (or even 113s).  If your customer is looking for a good street machine and nothing more you can just run the "C" heads as configured with the 1.78" intakes, you can also clean up the valve pockets a little to flow better, but it will run very nicely with the smaller valves in those heads.

Oh, and welcome to the forum. 

   God Bless.   Tim                           http://yblockguy.com/

350ci Y-Block FED "Elwood", 301ci Y-Block Unibody LSR "Jake", 312ci Y-Block '58 F-100, 338ci Y-Block powered Model A Tudor

tim@yblockguy.com  Visalia, California    Just west of the Sequoias

First welcome to the site. Further to what Charley said, if you want the 9 to1 compression you probably need to cut a few thou off the heads also. The original advertised compression was somewhat optimistic & that was with steel head gaskets. Some here like the "C" heads in spite of the smaller intakes. However, for a more serious engine the "G" or 5752-113 heads are preferred. But a caution with the "G" heads, their decks don't take kindly to heavy milling..

Paul

Hello Warren and welcome to Yblocks are us. Tell us some more about the vehicle that this motor is going into. Is it a stick or a Ford O matic and which rear gears? The reason I ask is because if it is a Ford O matic then pick a cam with good low RPM torque charactoristics. You can put big valves in the ECZ C heads with good results but keep in mind the exhaust of the Y block engine is very restrictive and porting here will pay off more. When guys here tell you not to mill the G heads too much, they mean the unposted ECZ G heads. (look it up)

   In 1956 Hot Rod Magazine and Edelbrock built a Yblock with ECZ A heads ( similar to ECZ C heads ) and got 300 HP from 320 cubic inches. They used the big valves and milled the heads a lot with great results.

   Y blocks with an A/T like low end torque over high RPM horsepower. Let us know how it turns out and what you learn. Pete

Thanks for the info/opinions.  I may have been optimistic about compression using the advertised numbers from the seal power catalog.  I compared the comp ht. from the 292 and 312 offerings and chose the one with the highest which the book showed as 8.7.  I intend to leave the piston about .005 in the hole and planned to take about .020 off the heads to compensate for the composition head gasket.  The guy is putting this in a 54 pick up with a manual trans and the stock  dana rear.(3.91?)  He is also going to assemble the engine so I'm just trying to do some good machining on my end so he ends up with a good outcome.  My recommendation to him as far as camshaft is along the lines of the Mummert middle cam, about 270 adv degrees and .450 lift.  Do you think, considering the ports, there might be an advantage to putting in the 1.62 exhaust valve and leaving the 1.78 intakes?  Considering his intended use, staying with standard is probably better, but I'm fighting the urge to tinker for the better.

Warren

I would also consider the 1.84" intake valves. What ratio are the rockers? There were two ratios made; 1.43:1 and 1.54:1



If you need valves, I'd at least make the additional investment to get the larger intakes.



That cam seems a little 'sporty' for a truck. The '57 cam is another good choice.

Best regards,



Paul Menten

Meridian, Idaho

I have a 292 .060 os with 113 heads, 72 cc originally.  I  cut the heads .035 and decked .028 to get .004 in hole flat top pistons.  Ended up with 9.2 static cr.  If it were me I would stick with the orig. intake valves, take .020 off heads, and deck it .020, hoping the intake would line up ok.  If not ok then some material removal would need to come off head's intake flanges, approx. 1.4 times the net loss from heads and deck, in this case .028. 

Mike, located in the Siskiyou mountains, Southern, OR 292 powered 1946 Ford 1/2 ton, '62 Mercury Meteor, '55 Country Squire (parting out), '64 Falcon, '54 Ford 600 tractor.

I'd stay with the stock size on the exhaust and go with 1.84 on the intake.


Lawrenceville, GA