Technical Y-Block Cam Choices

Some of you may have seen that I am currently building a 312 for my 56. The old 292 in it is getting pretty tired at around 120k miles with no previous rebuilds and a good friend gave me a 56 312 probably 10 years ago to build for this car. Anyway, I have recently gotten everything back from the machine shop and need to pick a cam to start putting everything back together. So, as far as background, this is basically a bone stock 56 312 that is now .030 over and has ECZ-G heads. I am planning to continue running the 57 intake that I have had on it for about 10 or so years now so I can run a more modern 4 barrel than the T-pot. Also, I’m converting the car from automatic to a three speed while doing all this.

So, my question revolves around picking a cam that will work well, sound good, and not go flat during break in…. Where should I start looking or does anyone have suggestions? This is my first y-block to build and I don’t want to make the same mistake I made years ago building a Pontiac where I picked a cam off specs that would work like a champ in a SBC…

 

Mummert is your guy.

 

I agree about Mummert, I’ve had 3 cams from him, all different and all good. He does the oil groove and runs them thru the cam Dr.

As a passing thought, his site list of cams shows “recommendations” regarding use. I’ve found those to be fairly conservative with a manual transmission. Maybe I’m just less sensitive to a little higher idle or a bit of lumpy idle. Just FWIW.

 

I agree with Mummert's. I put one of his mild cams in my 57 T-bird and was very pleased. It was a Y-256-F, good idle and good all over performance. I drove the car for about 20 years with that cam.

 

If you are going with a floor shift, I'd consider using a 5 speed. Whole lot more driveability with a couple more gears. You can put a plain knob on it so no one knows. Get a crate and save all the parts you remove in one place.

 

I second that motion... Changing from 3sp to 5sp made a huge difference on my car. If a 5sp offends your trad sensibilities then at least get a 3sp with an o/d (I think this was available on the 3sp toploader which a lot stronger than the older box).

 

Well, I have a 3 speed with an OD that I was considering putting in the car. And, this car is so original that I sort of hate to put anything in it other than something that could have been put in it when it was new or close to new. To me, there is just something cool about a 3 speed on the column in a car like this. I have nothing against a floor shifter or 5 speed, but not sure it fits my vision for this car. And, I already have a box of the original stuff I have changed out on this car. It was too good of a survivor to not save all that stuff.

Thanks for all the comments so far! I have followed Mummert some including watching some of their youtube videos so will likely check with them on what might work best.

 

I have always liked the old 3 speed with overdrive transmissions. I had two car with this setup. They are the smoothest sifting transmissions you can get. This is because of the overrunning clutch in the OD unit. In fact, you can shift them without a clutch release as long as you are under OD speed. Both my cars, 58 Impala, 54 Mercury, were set up as they came from the factory. Get above about 28 mph, let up on the throttle and you were in overdrive. If you wanted to pass, just floor it and the trans would go back to direct. Sweet setup.

 

I’ve always had tbirds so I’ve always had a floor shift. I’ve replaced T86’s with T85’s, T&C (or whatever they’re called- 4 speed with 4th being an o/d) and T5’s. The only real advantage is the syncro first gear. Life in greater Seattle is on hills, and crawling up them in traffic is a pain without syncro low.

An oem manual column shift will work fine with the 85’s and 86’s. The o/d lets you put a 4:11 rear in, and it’s a great combo. Good around town, great on the highway, and all well proven factory parts. You won’t want to be side stepping the clutch on an 86, but it’ll live behind a 312 if treated well. If that’s on the table, it’s well worth it.

 

Thanks for all the info! What I have is a T86 if I remember right. It supposedly came out of a 56 T-bird. And, I don’t plan to be side-stepping the clutch in this car. If I want to drive something hard, the Chevelle is for that with a 4000 stall, 4.10’s, lots of HP and slicks.

 

Mummert will give you good recommendations on a cam. he usually sells Isky. BUT So does Ted Eaton and he's much closer to you for shipping. If you get an isky you can get the whole kit lifters valve springs, pushrods etc. and know that it is all a matched USA setup. Ted's a wealth of information and easy to talk to on the phone.

 

It seems like the Y block has a select few cams, seems like every combo has been tried. Lots of guys default to their favorite grind. Not a lot of variables.

 

Thanks Chris. I was looking at that yesterday, but posting it here may also help others later.

 

I look at it all the time. I was pondering the Y-292S. I will probably run a T5 or equivalent.

Who did you find to do the machine work?

 

I used Balsiger Machine here in Guthrie. He has done several engines for me over the years.

 

I have always heard the Y block is peculiar, not sure if that is an old wives tale.

 

I think the most peculiar thing about a Y block is the timing chain. Unlike most other engines, you do not line up the dots on the cam and crank gears. The timing chains have marks on them and you line the chain marks with the dots on the gears with the marks aligned on the drive side of the chain (right hand side when facing the front of the engien).

 

I ran a a 270 cam in a 9:1 320 stroker. T-5, 3.73’s, t bird. 2.9x 1st, and 0.8 o/d. Good street combo. That was some years ago, so the spec may have changed a little. I also ran one of the 280’s in my 340 F clone. Can’t remember which separation it was. It was fine behind a stick. I’d say either one would work for you with the o/d and 4:11’s, but I’d probably lean towards the 270 for a full size cruiser. And for sure with taller gears or no o/d.

 

Thanks! From those choices, the 270 is the one that appeared to likely be the best choice.

 

J.C. Whitney "3/4 race cam...."
does that give away my age a little?

 

Isky makes a couple good cams also. One is the old RPM 300, and there’s one a little milder. Ted Eaton uses those (among other grinds, often custom). So you can look at specs and you’ve got some choices.

The RPM 300 is probably what the 3/4 race JC was based on. I remember those too.

He also discusses the various solutions to center cam bearing oiling issues and solutions. From harder bearing material to grooving the block or cam for upper end oiling. Here’s his quick index, it’s worth having a look at (just an item at a time, it’s a long list or articles.

John Mummert and Tim McMasters also have articles or tips, not discounting them, I’m just more familiar with Ted’s work.

https://www.eatonbalancing.com/2000/03/24/quick-index-for-eaton-balancing-articles/

 

I think the 270 would behave similar to a Comp Cams 268H in a sbc. I know….apples and oranges, but….

 

I run a Isky E3 in my 292 wicked sound good top end must run a stick tough.