Author Topic: Stock 352.  (Read 2819 times)

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WerbyFord

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Re: Stock 352.
« Reply #15 on: January 02, 2019, 12:49:28 AM »
I forgot to ask. Would using the cometic head gaskets that have a compressed thickness of .027 be worth putting since I have one head off? Or just save the money for the stroker build?

Given your plans, I wouldn't bother. "Quench" is called the distance between the piston top and the cylinder head quench pad. Ideally about .040" so the mix gets "squeezed" in there, improving swirl and combustion. Quench is probably a bad name for it. You cant go less than about .040" total (deck clearance + gasket) or risk piston banging into the head. But as Ross said, more Quench is more soggy. I think there's SOME benefit to lowering quench below .100", Ross says .060", ok somewhere in there, tighter is better, .040" is about ideal.

Those pricey gaskets aren't going to affect that much.
I'd keep that fresh 352 block then, but put a way smaller cam in it (even a used one w matching lifters, just a stocker), just a good running smooth idling good-on-gas 352. Then build your next engine for whatever your plan is.

That's right - you'd need crank-rods-pistons to make a 390. Not exactly free but pretty cheap for parts anyway. I just wanted you to see how much difference it would make, so you know why that 352 plus that cam is so soggy in a heavy tall geared car.

My427stang

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Re: Stock 352.
« Reply #16 on: January 02, 2019, 10:30:54 AM »
Sorry for the late reply.  Werby pretty much hit it all though, I'll write a little book though :).

First, look at most any head and piston other than a hemi.  Even the lowest compression engines have a flat pad on the head and if possible a matching flat pad on the piston.  Modern thinking has even gone away from a standard "dish" (except in very purposeful choices) to an "inverted D-cup" which is basically a copy of the quench pad and combustion chamber.

The issue of course is we have to package everything along with a fixed location of the valves, multiple valve sizes, etc, so it's not perfect, but you'd like the smallest combination of head chamber and piston cup you can.  Not in terms of volume, volume determines compression ratio, but in terms of direction in each way, length, width, etc and as clean of a path across the chamber to allow the mixture to move around as well as the flame to travel quickly. (no domes, bumps, funny shapes)

Then, everything that is NOT that combustion space, you would want to almost touch at TDC  in operation. 

Think of what happens in the cylinder, piston drops, atmosphere and cam overlap starts filling the cylinder, the cylinder rises, the air and fuel is compressing, and when the piston's quench pad(s) and head pad(s) almost smack into each other, all that air and fuel is churned, tumbled and forced into the chamber/piston cup.  Some people actually call them "squish" pads, not quench

Then the engine fires, that chamber has a small distance for the flame to travel.  The air and fuel is nicely mixed up burns evenly, and it starts pushing on the piston as heat rises and gasses expand.  The benefits are 1: Everything is churned up and one place, 2: a neat clean "chamber" allows a  fast flame front 3: the complete burn means less chance of detonation, the clean edges and less surface area can mean less chance of preignition.   This is better everywhere.  You even need significantly less ignition timing. 

Then think of something like yours, piston rises, it starts to move things around, but only goes to a certain point.  Additionally, when it fires, even at the same compression ratio, the flame front will have to travel across 4 inches of bore, and 1/2 way across that, it will hit the edge of the chamber in the head.  To counter that, you need MORE advance to fire early enough to make power.  Ironically though, because there is some unburned fuel near those shadowed spots during burn and maybe some that didn't get churned up nicely, you have a significantly higher chance for detonation (ignition from heat after the spark plug fires).

If you look at builds around the dyno pages, look at a modern chamber/tight quench, they can get to the point where they only need 24 degrees of timing to hit max power, but the looser versions need 40+ degrees of advance.

The ironic thing is, the engine that requires more advance, is less likely to tolerate it, that's the punch line for you.  Until you get significantly tighter, your engine will want more and more advance, but it will likely ping.  So raising compression is OK, and recurving is OK, but one is a lot cheaper than the other, so I am trying to find you some "free chicken"... basically what can you do to live with it and spend little right now.

There are also benefits on the exhaust stroke, same thing but think of exhaust rushing out of a smaller area and being pushed that way, reducing hot spots and giving a more focused area during overlap, but the compression stroke is good to picture the majority of the benefit.

So now, I keep preaching the ignition advance.  Going back to the loose quench scenario.  Ford uses and real slow advance and late initial.  If you can get the timing to start at a higher initial, and come in a bit quicker, but not so quick that it pings, you will get some part throttle power. That would cost 100 bucks max and will make some difference, it won't turn it into a 390 or 427, but it gets some noticeable snap

Now I disagree about the benefit of headers.  However, I agree that you likely shouldn't buy them now.  If you sized the proper header for the engine, during your 40 degrees of overlap, it would fill the cylinder slightly more than stock exhaust will.  It's not a backpressure or flow thing, it's a negative exhaust pulse thing.  The problem lies that if you buy headers for the current engine, they would need to be very small diameter and as long as possible.  When you build a 390 or bigger, they may be too small.  That's the only reason I wouldn't buy them (and they probably don't make a tiny header for your car)

However, don't be discouraged, because if you decided to make some power, as Werby showed, you could get a 390 crank and rods, a the right set of pistons and you'd be making a lot more torque and power.  Additionally, you could even just buy a set of pistons and rings and make yours a modern 352 build, however, I think most would agree that sticking a 390 or 428 crank in there is better power per dollar.

Last comment, I do like the idea of just bolting it back together and running it (of course I would add a distributor recurve...insert dead horse).  Using your numbers, going from .132 quench distance to .106 is a waste of expensive head gaskets when you can buy a single 8554 for 15 bucks.  At that point, checking TDC with a piston stop and making sure your balancer/pointer is correct and having initial up near 14-16 with mechanical coming in quicker, you'll be happier and have some coin to save for the next step.

« Last Edit: January 02, 2019, 10:39:28 AM by My427stang »
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Ross

- 70 Fastback Mustang, 489 cid FE, Victor, SEFI, Erson SFT cam, TKO-600 5 speed, 4.11 9 inch.
- 71 F100 shortbed 4x4, 445 cid FE, headers, RPM , 1000 Holley HP, Bullet SFT cam, 4 speed

WerbyFord

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Re: Stock 352.
« Reply #17 on: January 02, 2019, 01:45:36 PM »
Ross gave a very good writeup.
I even think $15 is big money for a gasket, just old school.
I like to buy a whole FE gasket set every time I hit Summit - that usually gets me over the free shipping level.
Then I cannibalize as needed. You can never have too many open gasket sets.

Also - there ARE in fact some heads WITHOUT a quench pad. Notably the Cleveland-2bbl, later 351M 400M heads. They do burn clean, partly because there's NO quench area to "quench out" the burn after a long distance from the spark plug. But that long run distance (and lack of swirl) makes them detonation prone.

Ford tried that for a single year on the big Lima 429-460 with its bigger 4.36 bore, in 1972, with poor results. Knocked like a dog and ran that way too.
That design was dropped for 1973, going back to a quench pad. Much over 4" bore is just too far, when the flame has to go this far it will detonate instead. The Hemi avoids this by putting the plug in the middle.

I think the effort to get rid of the quench pad on the Cleveland, and then Lima, was to clean up emissions. "Quenching out" the burn means any hydrocarbons in there don't get burned. The advantage is you get Quench to avoid detonation, hence the name quench, and you also get swirl for a better burn all around.

I suppose the 352 is a torque monster compared to the 312 it replaced, but once the 390 hit the street, the 352 felt like a small block down low. Up high, it's hard to tell a 352 from a 390. They were both rated at "300" hp, LOL. In reality the 352 made about 270hp but the 390 only made about 280hp so not much difference on top end. But a HUGE difference flooring a big Galaxie away from a light with a 3.00 gear.

Dieselman966

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Re: Stock 352.
« Reply #18 on: January 02, 2019, 10:20:58 PM »
I appreciate the lesson guys. So with out a better quench the fuel air mixture doesnt mix as good which can cause problems with higher compression.  Makes sense.

I'll grab a matching head gasket and slap it back together and I'll look into recurving the distributor.  As far as headers go I already bought a set of Sanderson headers. I was installing them along with building the new exhaust when this whole other snowball got ahold of me.  As the saying goes curiosity killed the cat. 

GJCAT427

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Re: Stock 352.
« Reply #19 on: January 03, 2019, 06:03:45 AM »
I`m planning on being there. Still got a lot of work on the new motor for the 63. Getting the bottom end balanced and should get it back fri or Monday.

Dieselman966

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Re: Stock 352.
« Reply #20 on: January 09, 2019, 07:53:57 AM »
Changed my mind again lol. Pulled the engine out and got it on the stand. Talked with the machine shop and the said $360 to deck the block if I bring them just the block another 200 and they can rehone the bores for new rings.   Saves $1000 dollars over going to the 390 or bigger crank.

  Whats a good cam recommendation seems how it gonna be out for machine work?  I think I'll be switch to some 3.55 gears also.

RustyCrankshaft

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Re: Stock 352.
« Reply #21 on: January 09, 2019, 07:59:15 AM »
If you have it torn all the way down to square deck I would say spend some of that 1000 you saved by not going to a 390 and call any of the Triple B's (Brent Barry Blair in no specific order, or any good FE builder of your choice) and get a cam ground for your combo and I'd consider going hyd roller. Big fan of hyd rollers on the street.

My427stang

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Re: Stock 352.
« Reply #22 on: January 09, 2019, 08:05:56 AM »
Changed my mind again lol. Pulled the engine out and got it on the stand. Talked with the machine shop and the said $360 to deck the block if I bring them just the block another 200 and they can rehone the bores for new rings.   Saves $1000 dollars over going to the 390 or bigger crank.

  Whats a good cam recommendation seems how it gonna be out for machine work?  I think I'll be switch to some 3.55 gears also.

Are you saying you are going to cut it to fit the pistons you have?  or get pistons that are closer?  I wouldn't cut the block to fit those pistons, I'd get new pistons if you want to stay 352.  That's a heck of a cut
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Ross

- 70 Fastback Mustang, 489 cid FE, Victor, SEFI, Erson SFT cam, TKO-600 5 speed, 4.11 9 inch.
- 71 F100 shortbed 4x4, 445 cid FE, headers, RPM , 1000 Holley HP, Bullet SFT cam, 4 speed

CaptCobrajet

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Re: Stock 352.
« Reply #23 on: January 09, 2019, 08:23:17 AM »
I keep 352 pistons on the shelf here, just FYI.  They are 4.062 bore, so you would have to bore it.  I adjusted the compression height back when I first did these.  I'll look today and see what the CH is on mine.  Nice CP pistons, forged flat tops, modern rings, etc......nothing on a shelf anywhere else like these.

You should probably surface the deck, but you wouldn't have to cut it to death.  I'll post the CH later.
Blair Patrick

Dieselman966

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Re: Stock 352.
« Reply #24 on: January 09, 2019, 08:47:30 AM »
Rustycrankshaft
I'll get in touch with one of those guys for a camshaft.

My427stang
Where would be a good place for custom pistons with the correct compression height?  Talking with a local machine shop about this and the cost between decking the 352 and stroking with a 390 rotating assembly will cost $1000 more. 
On a side note my measurement wasn't accurate for piston in hole depth.  I was going off the wrong mark on the balancer for tdc. I'm waiting on my dial indicator to show up to find tdc and remeasure.  Guess I should have posted here before I ripped the motor the rest of the way down.

Captcobrajet
Sounds good. I'm open to ideas here.

My427stang

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Re: Stock 352.
« Reply #25 on: January 09, 2019, 08:53:30 PM »
Rustycrankshaft
I'll get in touch with one of those guys for a camshaft.

My427stang
Where would be a good place for custom pistons with the correct compression height?  Talking with a local machine shop about this and the cost between decking the 352 and stroking with a 390 rotating assembly will cost $1000 more. 
On a side note my measurement wasn't accurate for piston in hole depth.  I was going off the wrong mark on the balancer for tdc. I'm waiting on my dial indicator to show up to find tdc and remeasure.  Guess I should have posted here before I ripped the motor the rest of the way down.

Captcobrajet
Sounds good. I'm open to ideas here.

We have at least one piston manufacturer on here and he could easily make you a 1.87 compression height piston for a 10.160 deck with whatever dish or D-cup you desire, I'd say leave it up to him to PM, otherwise, Brent, Barry, or Blair all have companies they use to do the same.  Of course Blair already chimed in with a set

They won't be dirt cheap though but will only bite once

As far as your comment on TDC, let me offer you an alternative that is easier and more exact. 

- Find a piece of strong metal, maybe 1 inch x 1/16 or 1/8 flat stock, bend a 90 degree so you can bolt it down using a head bolt and it will hit the piston
- Bolt it solid, turn the engine by hand until the piston hits the metal, mark the balancer near the timing pointer. 
- Then go back the other way until it hits again. Mark the balancer  again. 
- Remove your piece of metal, and measure exactly between those two marks on the balancer.  That is TRUE TDC.  It should be the same place the balancer says TDC, but it may be a little off
- Turn the engine until your new mark lines up with the pointer.  That is TDC, and eliminates all variables (assuming you measure the ceter point accurately)
- The dial indicator is tougher, can be off a little because both piston dwell and rock can add a little variance
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Ross

- 70 Fastback Mustang, 489 cid FE, Victor, SEFI, Erson SFT cam, TKO-600 5 speed, 4.11 9 inch.
- 71 F100 shortbed 4x4, 445 cid FE, headers, RPM , 1000 Holley HP, Bullet SFT cam, 4 speed

CaptCobrajet

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Re: Stock 352.
« Reply #26 on: January 10, 2019, 04:33:33 PM »
The pistons I mentioned a couple of days ago are 1.875 compression height.  The 8554PT and the 8045PT gaskets are .051 compressed.  10.155 to 10.160 would give .040 to .045 quench.  Generally speaking, a cleanup of .010 on the deck would make it nice.  Would only be around .005 in the hole if you took a chance on not doing a cleanup mill.  I have 6.540 length Molnar rods here to go with the pistons if you wanted light, strong replacement rods.

I also keep 4.035 pistons on the shelf for 4.250 crank and 6.700 rod Strokers if you really get the bug.........
Blair Patrick

Dieselman966

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Re: Stock 352.
« Reply #27 on: January 10, 2019, 05:40:41 PM »
My427stang

 I have plenty of metal laying around to make up a tool like that. Sounds easier than messing with the dial indicator.  I'll talk with Blair about his pistons some more.  Sounds like I'll have less problems with the pistons instead vs milling the deck that far down. I'm guessing the intake wont line up very good if I take that much off the deck.

Captcobrajet

I'll PM you for a price on those pistons. Are the stock rods not good for around 300 hp?  I'm just trying to get this 352 to run better.  At some point I'll be building a stroker for it but that's down the road quite aways.  I have a $1000 budget  could maybe swing $1200 to get it done.  What's the best option here?  The machine shop here said $400-$600 for a bore and hone job. Decking the block is $360,  $75 to mill each head and 200 to hone the bores to ensure a good seal.  Looking at $710 plus tax to go that route.  I'll call around to a few other shops in my area and see what they have to say too.
« Last Edit: January 10, 2019, 06:31:06 PM by Dieselman966 »

CaptCobrajet

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Re: Stock 352.
« Reply #28 on: January 10, 2019, 06:54:35 PM »
Your rods would be fine for what you describe, as long as the big end bore and bolts are in good shape.  Those rods are "skinny" but I have taken hundreds of those engines apart over the years, and I don't think I ever have seen one broken in a regular service engine.  I knew a guy (Kip Martin) who raced them at 8500 rpm in a 352, but he knew how to fix the big end to live there without turning bearings.    Beams didn't break!  Sent you back a PM.
Blair Patrick

Dieselman966

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Re: Stock 352.
« Reply #29 on: January 14, 2019, 08:10:06 AM »
I finally got some measuring done on my block.  I'm seeing as much as .010 from my highest measurement of .0705 to my lowest of .0805.  Seems like a  lot of variation or is this pretty typical.  My tdc was off by one degree. Checked with a hard stop.