Breathing new life into the 318 in the Scamp!

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I agree on both accounts.

The more I look at this, the more I think it's easier for me to run the KB pistons, because it will put the quench up in the head, rather than down in the cyl. under the tight end of the head, with bad quench and I won't have to possibly correct other issues.

I'm starting to lean away from the magnum pistons, because of dynamic and quench.

I mean, look at this... This is true TDC. -

318%20TDC%20154.jpg


It's not even close to factory spec, which was awful to begin with.

So, as not to do any guess work, I set everything up tonight after work and checked the head.



318%20302%20Head%20CC%2001.jpg


Amy didn't have any food coloring, so I went for the liquor cabinet. Surprisingly, the sugar from the Grenadine with alcohol helped quite a bit with bubbles.

318%20302%20Head%20CC%2002.jpg


This first run had a little more grease than I liked and looked like a little over 61cc, so I cleaned it up and rechecked it with less and it is at exactly 62cc as I suspected, with these valves and the plug installed.

The gaskets are a little more forgiving than I expected which also helps my final numbers on these KB's.

These mic at .055"
318%20head%20gasket%20uncompressed.jpg


The gasket is a Fel-Pro 8553PT

They will crush at anywhere from .048"-.045" which, in this case, helps what I'm trying to do with the KBs. Basically, I'm trying to avoid buying high octane fuel and hitting ping. If I can get this engine somewhere in the static of 9.0-9.4 I think I'll be ok on dynamic with 3° Adv.

I think it's time to pitch on these-

http://www.summitracing.com/parts/uem-kb167-030

So, with all of these numbers IRL in mind, this engine should pan out a static floating right above and below 9.4:1, depending on what I get out of the gaskets (.045"-.048") without any additional work on the heads, but I'm really tempted at this point to blend the tight sides a touch.
 
I would strongly recommend putting away those head gaskets and getting some 1008 gaskets, they have a compressed thickness of .039" which will give you much better quench than the 8553s... your compression will be a little higher but it will actually be less detonation prone. I used those gaskets and with the heads on my 360 (but bolts not fully torqued) actual quench distance measured at .045".

Look at it this way, with KBs your engine will be basically the same as mine and I run 87 octane with no detonation unless I punch it when it's hot and sunny outside. Your engine due to having a smaller bore will have at least .5 less compression so it should run even better on pump gas. Also take into account I have my timing set at 16* initial and 35* total which is a bit on the aggressive side; bumping it down 2-4* would probably allow me to run 85 octane if I had to. One last thing you mentioned you will be running 3.91 gears with the O/D trans, that will give the engine a lot more leverage accelerating compared to my car as well with the 904 and 2.76 gears which will also reduce detonation.
 
I was thinking about the gaskets and the spot under the tight side.

Maybe if I do both, tighten the gasket and radius the tight corner of the chambers, I can keep the cc's up, but put everything where I want it.

What I don't want to do is hit ping climbing a slight grade in O/D on min octane, but I have also taken into account that any hills will be higher in altitude, so I'll have inherently richer mixture.

.039 will put the static @ 9.56:1 without any head blending. I'm beginning to think I should make a template, mark the chambers and start a radius blend the tight ends and move around if I need more. If I got 1cc out of them, that would bring static down to 9.46:1 and help flame.

What are you getting for cyl. pressure?
 
Done deal. KB slugs and 1008 gaskets are on the way. Now I get to play the waiting game and hopefully, I can get some of my money back on the other parts. I'm not holding my breath.

I think during the wait, I'm going to make two X and Y axis templates for these heads, start to radius the valve sides and cc all of it.

I may need more Grenandine.
 
Hell yeah man I'm excited to see it running... I haven't actually checked my cranking compression but I would guess it's pretty high, up around 190? I've been meaning to do that, probably will soon.
 
Good tech,both of you ! The magic number,for quench: .038" to .045",obviously could be stretched. Probably the most intelligent conversation, I have seen in a while.Thanks.
 
If these pistons sit .012 down, should I run a tighter head gasket than .039"?

I'm wondering if Something like an .028" would be more ideal? That would get me right in at .039 or a scratch over.

The .039"s are getting me in at .051" quench.

I'm a little concerned about longivity of the .028" Mr.Gaskets, but I don't know if it's relevant.

Does anyone make a gasket somewhere inbetween .039" and .028"?
 
Cometic can make gaskets custom for you, but it wouldn't be cheap...I wouldn't worry about longevity of the .028" gaskets unless you think the mating surface is anything but flat...the factory gaskets in many instances were simple steel shims with sealant dip on them.
 
United Engine says a perfect quench is .035". I'm going to try to get as close to that with my 383 as possible.....IF I ever build it. lol What I plan to do is zero deck the block (already done) and use the head gasket compressed thickness for the quench distance. Mine is going to be abour 10.4:1, but then again my cam is 270* @ .050.
 
The Chevy Power Book(yes I know...). States quench most effective .038"-043". Anyway you get there. Sorry,don't want to hijack the thread .
 
RustyRatRod said:
United Engine says a perfect quench is .035". I'm going to try to get as close to that with my 383 as possible.....IF I ever build it. lol What I plan to do is zero deck the block (already done) and use the head gasket compressed thickness for the quench distance. Mine is going to be abour 10.4:1, but then again my cam is 270* @ .050.
Click to expand...

I recall reading that article before or one like it; but I also recall it going into a little more detail along the lines of, street engine that rarely sees higher than 6k with stock type rods.

I know guys running 4.6s inside of .030", but they're also running Carrillo rods and ARP 2K rod bolts, tool steel pins, and the bobweight is significantly less...4.6 pistons only weight like 350g...

I've been playing with those numbers myself for my eventual 383...
 
Saw the Cometics. I don't think it's quite worth it for a street engine. Total .039" is nice. I think I'm going to run .028"s... I just bought the .039" set. The 28's are half the price, too. How 'bout that. Time to return more parts.
 
I can't disagree with that assessment...you really only reap benefits from the cometic gaskets if you foresee having to pull the heads a couple times, as they are reusable...
 
One of the guys over on the B body site has run .019-.020 quench more than once with success. But even he said it was not a high RPM engine. I got no problem slingin one to 7500 with a .035 quench distance. I plan on doing just that.......maybe one day. lol
 
Abodybomber said:
The Chevy Power Book(yes I know...). States quench most effective .038"-043". Anyway you get there. Sorry,don't want to hijack the thread .
Click to expand...

Lay a chebbie rod down on the table. Now a MoPar rod. Get me???


LMAO.
 
Alright!

318%20KB%20piston.jpg


Time to put some metal down!

Still no word on returning the awesome .154" compression distance set. More pics soon.
 
Got the pistons pulled, sending them to Don tomorrow to have him center up the pins. Rods and caps are numbered, so it should be a snap this time.

1121G's on the way.

Love you.
 
Make sure your engine's clean, now. Can't have no dirty heads. All the engines here, are clean, boy. All the building in piston hell.

Digging this back up from the grave, this evening.

I like the way this looks;

Scamp%20318%20KB%20measure%2001.jpeg


Scamp%20318%20KB%20measure%2002.jpeg


It's so nice to buy parts that are what you expect them to be. It sure makes things move along.

I was shocked at how correct the balancer was, but then again, aside from high detergent oil, this engine has had a pretty cush life. I think I corrected it about a degree or maybe half a degree at TDC on the dial (-° @ .060" +° @ .060"/2 to find TDC).

Scamp%20short%20block.jpeg


These pistons rock quite a bit less than the others. Perfect skirt clearances against the bores across all 8 cyl, too. I'm pretty happy with how everything spec'd out on this engine.

Got the short block done and in the car. The urethane mounts required spanning the K frame ears a little and they will not deflect at all. It could stand the block even on the front mounts, alone. I had to remove the trans tailshaft eye bolt for additional crank to converter clearance, but none of the linkage or wiring had to come out for the trans.

Scamp%20engine%20install%2001.jpeg


Scamp%20engine%20install%2002.jpeg


It got dark, so still have to crawl under and do the flex plate bolts. I took the lifters back out to spin the engine, but the cam is in and ready to go. Went in beautiful, bearings are dead on, oil holes are great, much respect to Don Hackenberg for the bearing install and journal clearance checking.

Did some prep work for Amy's stickshift request. More on that soon.

Scamp%20Bellhousing%20index.jpeg


.0175" out, going to round up and call it an .009" offset dowel. Ordered those and marked the direction on the bell. Checked crank depth and I have no idea if I'm going to have to drill until I do more measuring. Do all of that later.

302 heads are torqued to 85, sequenced 3 times as per Mr.Gasket requests, rather than twice, per my '68 Chrysler manual. I think I'll leave them there and check thickness before the intake is marked, centered and goes on, tomorrow with the valvetrain.

I dream of exhaust notes and photo shoots in go-go boots for the weekend.
 
Keep it up you will be running by this weekend.
 
great progress. i have a 318 sitting in my dart that i would like to go through befor the summer is gone. this build is kind of what i have had in mind on a budget.
 
Got everything buttoned up, down to the wire dividers.

Primed the fuel with the mech pump by hand, got a couple of leaks at the chromed pot metal joint of the regulator, to the brass bushings that go out to the brass barbs. Pulled it apart, didn't use enough teflon tape. Put it back together, holds pressure @4psi, where I could run it with my hands, which smelled like 91 octane for an evening.

Came back outside today to get it fired, filled the cooling system up and found the right head gasket is weeping antifreeze at zero pressure, when I went to connect the exhaust manifolds to the head pipes. Pressure checked the system, trickles. Went to 95ft lbs on that side to see if it could take care of it, still trickles.

I suspect a crooked replacement cylinder head. Pulling the heads back off and sending them to get milled. The last set ran fine, no leaks, on factory metal shim gaskets (1)75K+ on the Odometer. Block is fine. Never overheated.

Bullshit.

Moral of the story;

Test everything before firing a mill. Walked away when I was straight edging the heads for deck, I think I did the same one twice. Other side seals, but I'm milling both heads, anyway.

Boooooo...
 
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