57fordluvr,

I did not notice your message on page 2 before responding to Ted's message.  I am getting a lot of good ideas here and obviously have to continue working on this.  Sounds like my main limitation may be trying to squeeze larger diameter header pipes into a car without routing through the fenders, which I will not do on this particular car.

I did not understand your comment that you got your headers from Jerry just in time.  I have tried to reach him without success the past week.  I hope he is OK.

57fordluvr,

No apology needed.  I just wanted to make sure I understood.  Regarding your detonation problems, I melted the corners off a good set of pistons and broke all the rings in a small block 400 in my 78 Ford pickup a few years ago.  I thought part of the problem was my old ears not hearing the detonation, but have been told since that with the new gas these days, you can't hear it pinging.  I put in pistons with less compression, and not trying to optimize performance in that rig, I welded a small knob on the spark advance lever to prevent it from advancing too far.

The 312 I am building for a blower will run relatively low compression, thus eliminating a lot of tendency to knock.  That and a good modern electronic ignition system should keep me out of trouble.  Has anyone tried an antiknock sensor on a Y-block?  I wonder if they will work with solid lifters thumping away?

That’s a lot of boost.  Suggest you retap the block and redrill the heads for ½” head bolts for an increase in head bolt torque.

Exhaust flow is important in your case so concentrate heavily on the exhaust ports.  I had the same intake flow limitations with Randy’s 113 heads that you have but boost breaks all the rules in that it will force the flow in place rather than just have it flow in a more docile nature as in a naturally aspirated engine.  Even if you have more residual boost before the open valve, you will still benefit from the increase.

If you can make the 2” headers work in your chassis, then go for it as the major bottleneck in your system will be at the head just after the exhaust valve.  The gases can then freely expand into the 2” pipes and provide a bit of scavenging that you wouldn’t have otherwise at full throttle.

Lorena, Texas (South of Waco)

Since he's not willing to sacrifice the appearance of the car to more easily fit the headers, I'm assuming it will not be run at full throttle all the time. I get the impression that it's not a race car. I'm getting more of a sleeper or cruiser impression which will be operating mostly at part throttle. Will the 2" pipe theory still apply?



Does the same theory apply to Turbos?


Lawrenceville, GA

The 2” theory only works at full throttle and then only if the exhaust system itself is relatively unrestricted.  The same thought process should also apply to Turbos.

Lorena, Texas (South of Waco)

I keep hearing the 6-12 lbs boost and Hyper-eutectic pistons. That's NOT a good idea, be much better and more Detonation Resistant with forged pistons. Shoot for around 8 1/2 to one and about 28 or 30 degrees total advance. You'll want to keep plenty of octane booster around also.

Frank/Rebop

Bristol, In ( by Elkhart) 

With the cast pistons, and Hyper-eutectic IS a casting, I'd limit it to 6 lbs. John Mummert or Ted can put you on the path for ARP bolts (or studs and nuts). I find the bolts sufficient if retorqued per instructions, and I am using BEST Gaskets with this combo. I'm around 8 lbs, or that's what I'll admit to! No problems so far when the timing is set to 30 degrees or so maximum. I do use an octane booster or 110 octane at the strip. 93 and common sense seem to work on the street. 

       For what it's worth the diameter of the primaries would be based on the horsepower you plan to make. It's basically a function of the volume of exhaust gas you generate and how fast you want it to travel. For a number I'd go to about 1 3/4" primary, as long as you can get them in the car, and a 3" collector. I think that's about where Hoosier is with his fenderwell headers, and it works for him. The 2" will kill any low end you'll have left, for street use.

       Are you talking to Frank Stubbs?   

Frank/Rebop

Bristol, In ( by Elkhart) 

Dan,

       Stubbs is well known in the Y Block community. He produced a series of "F" code air cleaners and is considered quite an expert on all things "F" code. I have one of his reproduction air cleaners on my F code Custom 300.

Frank/Rebop

Bristol, In ( by Elkhart) 

Why are the stock manifolds upswept?  Why aren't any headers made like that?


Lawrenceville, GA

To the best of My knowledge, the stock exhaust manifolds are upswept to maintain the upward flow started at the exhaust valve and then give them a gentle bend to head back down for better flow. Don't know why most off the shelf headers aren't that way, probably just easier and cheeper to make.

   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