Projects '62 Ford Unibody LSR Truck

14:1

I hope to by the end of the weekend. We'll see how it all turns out.

Mainly to fill in the chamber but it looks as if it will make some good turbulence.

 

Oh my goodness, pure Y block PORN!! Lookin good. For those who have not witnessed this truck, when it runs, everything stops so people can watch. It has a nice cackle, we all hope for another ride on Y tube Tim. As always, go fast, be safe.
Ole Don

 

Looks like some Ross pistons maybe (spent the first
six years of my "piston career" there). Hope the extra dome north of the valve pockets works for you, however I have found almost universaly that the added dome in front of the Int will "trip" the air/fuel coming off the backside of the valve and cause air/fuel separation issues, that typically lead to more fuel in and subsequently more timing to light it off. Also, in nearly every situation I can think of, that material north of the valve pockets will also upset "crossflow" during the overlap stroke. The cool thing is, you can run it as is, and later remove it if needed. I'm guessing that the removel would cost you 1-2cc of volume putting you around 13.75:1. The sides of the domes, i(3 & 9 o'clock ish), if they come too close the chamber they can also cause some air/fuel seperation issues, maybe a bit of radius there (.250-.500). I see you have a plug notch for plug clearance, there can be some power had if you slot that top to bottom, so that the top and bottom quench pads can "see/talk" to each other. You have built and raced Y blocks, and I have not.., but I wanted to add my 2 cents. The best way to explain the dome volume versus dome/chamber efficiency thing is this.., there is quantity, and there is quality, and quality (piston/chamber efficiency) will kick quantities butt everytime in my experience. Good luck, can't wait to hear how you run. PS. If you've never run your second ring gap bigger than the top (I suggest .010-.015 larger), you are giving up power and efficiency. If the cyl pressure going by the top ring fills the void between the top and second faster than it can escape, it will cause top ring flutter which really hurts the top rings ability to suck on the intake, and seal on the compression, power, and exhaust stroke. A pretty good indicator is the fuel curve going "haywire" in the upper rpm range. This also leads to the second ring being trapped by the pressure on top of it which will prematurely turn the tapered face, into a flat face and greatly hinder its ability to wipe oil off the cyl. wall on the "down stroke" leading to oil control problems. This pressure build up problem is much more of a problem in endurance engines/those that run for extended periods, but can also rear its ugly head in drag racing too. Alot of guys chicken out and run the gaps the same or .001-.002 bigger. Late GM LS motors are .009 bigger in most cases. I know of many very good racing engines that have the second ring gap .020-.040 bigger than the top, especially when using "power adders" ie Nitrous, blowers, turbo's. If your top ring is a gapless, then its not near the problem, or if the second ring is either ductile iron, or steel then the end gaps numbers can be smaller than those of a cast iron second ring, either way .010 bigger seems to work very well in all cases in my experience. Sorry to be so "long winded", but this can be worth substantial powe/torque, and I hate seeing guys assemble engines, not knowing that they may be giving up free HP, if they've never heard/tried this.

 

I almost always run a wider gap on the #2 ring but what are your thoughts on a "gas charged" top ring? I do listen.

 

The top ring is always pressure assisted vertically, because installed on the piston in the bore, the ring is outboard of the top land, so it always see's pressure above itself. The real benefit is from side loading assistance (tangentional is the fancy word), and is needed more as the ring thickness both vertically and radially is decreased (thinner top/compression rings, naturally have less tension and rely more on pressure assistance to do their job correctly). Many use the lateral/side gasport as you have, to reduce the possibility of the gas port becoming clogged with carbon, and subsequently non-effective, and many think that the side gasport will take longer to degrade the ring tension by keeping it cooler. The thing I like least about lateral/side gasports is that they reduce the rings ability to suck/pull on the intake stroke, (the more gasports, the worse it gets),becaus they create voids front to back in the ring groove roof. Suck a pen cap onto your tongue.., what happens when you put a hole in the end of the pen cap, it won't stay stuck on your tongue. When going from a lateral gasport to a vertical gasport, the engine will go rich (nothing else changed)because the piston/ring assembly will suck/tug harder on the intake/carburetor venturi (more fuel pulled). This allows you to dry up the fuel curve a bit (less jet/more air bleed etc.), which typically wants a little less ignition timing (always a plus). The vertical gasport is at the back of the groove, and since the ring seals on the outer portion of the ring groove roof & floor, the vertical gasport doesn't hurt intake pull, while it definetly will aid in side loading the ring.
Since the vertical gasport is more "excided" the ports actually stay cleaner, (we have proved this in Nextel Cup pistons as well as Australian V8 Supercar, and other forms of Oval Track/endurance engines). The ring tension life is no more effected by vertical gasports than latteral, because its already "in the furnace" so to speak. I would always run more endgap on the second, you have nothing to loose (remember, its just a wiper, not a compression ring. In the mid late 90's, GM did some testing with gapless O-rings, though they were able to achieve near zero leak down, oil control suffered because some pressure heading south helps aid in oil return to the crankcase. Some of my "ring buddies" hate me when I say this, but a gapless 2nd ring is the surest/best way to really piss off/inhibit the top and second ring from working properly. Many sprintcar engine builders used gapless seconds for years to reduce alchohol contamination in the oil, and the gapless second did seem to help, the real problem though is that until only recently (last 10-15years) everybody set the second ring gap tighter, which sends the top ring out of control, makes the fuel efficiency worse, causes the need for more fuel coming in to make up for fuel wasted (not burned) and just adds to the "big ball of @#$% rolling down hill". By increasing
second ring gap, many an alky burning oval track engine has realized greater power gains, with less fuel consumption/contamination. If its hogwash, them why are all the OEMs doing it. These engines make more snot at the rear tires with all the accessorie running than their 1990 and older engines made at the crank all while passing the most stringent smog laws and toughest government mandated fuel economy base lines to date.

 

Hey Tim, I forgot to mention, when ever you increase the engines ability to breath on the intake stroke whether its by better heads etc., or better ring seal on the intake stroke, you will increase pumping/dynamic pressure. If you have not run a compression check lately, it is still a good piece of info. You can check it at your place, and see how much it drops at Bonneville/El Mirage etc. because of the rare air. Speaking of pumping pressure, I have never seen any normally aspirated engine regardless of it's s size run good with more than 250-260psi, and for the world most of us live in, that number would be a max of about 215psi cranking with a starter motor. Only engines with extremely big crank strokes seem to have the mechanical leaverage to overcome the big psi #'s with out affecting power out put. Usually an engine with too much pumping/dynamic pressure comes on real strong, and then flat lines/hits a wall and won't rpm well, regardless of the valve train pieces.

 

Thanks Tim! See you in 3 weeks!

 

Thanks for the info, food for thought. as you see the pistons are made the way they are and I don't have time to change. I do see your point on the gas ports but what's done is done. I will run a wide gap on the second and just see how these pistons work as is for now. BTW they are made by Diamond. What company do you work for now? you said you did work for Ross at one time.

Cheers!

 

CP-Carrillo (CP Pistons & Carrillo Rods)13 1/2 years here.

 

Not even close to being an engine builder, and I honestly dont get all the stuff you guys are talking about. But I sure find it fascinating. Look forward to seeing you run again this year.

 

PM me and maybe we can talk about my next set.

 

okay, forgive my ignorance but I gotta ask this question... what's the secret formula for breaking the engine in? since it's an all out race motor, how do you seat the rings and such? are the rings cast, moly,???

 

Auwsome amount of Piston info, Motor looks Great!! Good luck on the salt Tim,,,,, Tim Jones

 

The modern rings are made very well and seat quickly. I get about 20 mins run-in time to seat everything and break-in the cam, then it's ready to GO. Secret formula? careful going together, check and double check clearances, when you first start bring up the rpm and don't let it idle for a long period of time. Keep a close eye on everything and shut down if anything looks odd.

 

This is getting better and better. All this info on your build, waiting for parts with ya, checking em out when they arrive, all this detailed engine tech.........
Next, the trip and the run.......
Exceptional

 

pure Y-Block Porn.............

 

I can't wait!

 

If the engine is done this weekend it looks as if I may have to do the swap myself. Anyone want to help in the 106* heat?

 

I be game but too far away!

 

Bring it up here Tim I have a hoist!
Lotsa help there huh Tim........

 

After much checking and fitting the short block is together, heads will go on tonight.

File to fit rings.



First piston in.







Cam timing is very important. It's not about just lining up two dots. (or twelve pins)





Ready for some heads.

 

Assembled with love and an old style ring compressor just like mine. I bought mine in 1961, when we you born Tim?

 

"Assembled with love and an old style ring compressor just like mine."
Is there any other kind?

Hey Tim did you get the lathe together??

Can't wait to hear the new rendition fire up!!! need a video fix!

 

I do have the pliers type but for small rings like these this style works best, more support. Don't want to break a ring. My name here gives you the year.

There will be video, don't you worry. Got to get it in first though.

 

That's the year I graduated from high school...Dang kids!

 

Dang old farts!

 

Damn I already had two years working for Uncle Sam by then.......

 

If ya can't stand old farts, stay out of the elevator.

 

Todays job. Put this in that!

 

6am. That looks like a damn good time to start. Early and cool !