225 /6's created equal?

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Pretty sure my old mopar performance manual says that all heads from a performance standpoint are the same. So basically any slant six head is a "good one". Did not even know they did away with the spark plug tubes on later castings, mine had them and they always leaked too. I think the hemi-tubes were the coolest part of the look for that engine besides the slant:)

Don't think there were many mods suggested for the heads other than milling for compression and general blueprinting. Most of the emphasis for extracting performance was raising compression, hotter camshaft, the 4bbl intake and exhaust work. The usual mods for any engine.
 
So if i'm seeing this right on the drool tube heads the plugs screw into what? On the peanut heads the plugs screw into the head? Nothing there for the plugs to screw into on the picture shown. Clue me in. Thanks
Small Block
 
In post #14 (peanut head) you can see the plugs screwed into their recesses if you look real close. The plugs are painted blue to match the head. In post #16 (drool tube) the plugs screw into a boss that is behind the hole the person's finger is in. The tubes sandwich between the plug and the plug boss inside and have a lip that seals to the edge of the hole being pointed to (in theory). Clear as mud yet?
 
Most drool tube leak because people dont change the gaskets every time they change plugs. And or they dont remove the "crush washers" on the spark plugs before they install them. What happens is the "PO didnt do it so i didnt either" once the crush washers are left in place the tubes are damaged slightly. This can be enough for a leak to start. Sometimes you can "fix" them with a block of wood, hammer and concrete floor. Tap them back into shape as they get buggered up on the plug end not the gasket end.
BTW im with Ceej my tubes DONT leak.
Frank
 
goldduster360 said:
Don't think there were many mods suggested for the heads other than milling for compression and general blueprinting.
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By whom? The #1 mod I've heard suggested for any SERIOUS slant is major port work done by someone with slant experience.

goldduster360 said:
Most of the emphasis for extracting performance was raising compression, hotter camshaft, the 4bbl intake and exhaust work. The usual mods for any engine.
Click to expand...

Cam, headers and 4bbl will have a minimal effect until you do something about the slant's port flow, which was designed for a 170 cube engine.
 
Bowl work is where the most gains are to be found on the street, AKA "pocket porting."

The MP performance book for the 6's has porting templates in it. I have recently copied them. Never used them when porting. I happened to read the book again and realized they were there! The size didn't change when I scanned them.

I recently ported a head for a friend and knew more than the last time. I took extensive before and after pics. The ports I did more for a truck VS all out performance.

If I can find them (I down load stuff and lose it in my computer!) they will probably need to be resized for posting here.
 
Small Block said:
Anyone have any of the old drool tubes laying around they want to get rid of? I'll take some if you are inclined to get em out of the garage. Thanks
Small Block
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I have a set here if you like. They are very light so I'm sure shipping wouldnt be a big deal (I'm in Canada)... let me know
 
vynn3 said:
Cam, headers and 4bbl will have a minimal effect until you do something about the slant's port flow, which was designed for a 170 cube engine.
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I dunno. Mike J is running in the 14's with a 2bbl Slant and a box stock head in his Diplomat.

I bolted a 390 Holley and Clifford headers on a stock long block and went faster than a lot of the guys with ported heads.

You are right though, good headwork is the key to making big power.
 
Had to chuckle @ 'drool tubes'.

Someone correct me if I am wrong: but did the 1966-71 426 Hemi's use said drool tubes as well?
 
vynn3 said:
By whom? The #1 mod I've heard suggested for any SERIOUS slant is major port work done by someone with slant experience.



Cam, headers and 4bbl will have a minimal effect until you do something about the slant's port flow, which was designed for a 170 cube engine.
Click to expand...

Stock 225 Hyperpaks made 196hp with high compression pistons, 4bbl carb and headers. I don't think the head was any different than a 170. A stock 225 from that era was rated at 115? 70% increase in power minimal effect with a 170 head? I wish I could get a 70% increase on my 360 with stock heads.

It appears not ALL heads were created equal either, here is an article from Dutra over at slant six.org
http://slantsix.org/articles/combustion-chamber/sl6-combustion-chamber.htm

The article claims there is hidden performance to be gained by massaging the head, which would apply to almost any engine.
 
Just be very careful when working the ports. More than one enthusiast has hit water getting carried away.

Look into bigger valves. There are lots of options. The Engine Builder valves are very popular, and require the least machine work. Best bang for the buck.

If you have a substantial overbore, 300 Ford Valves will work, but there is some work to do with that mod. The stems are smaller, so Guides need to be done. The seats need to be cut, or larger seats installed. That's tricky because once again, there's water to hit. This requires bowl work to keep from masking the valves, and if your industrious, relieving the bore for valve clearance and to keep the cylinder wall from masking the valve also.
With a .045" Overbore, I smacked some intakes into the top of the cylinder wall. Make sure the head is centered over the bores! My head is slightly offset to the rear on the stock dowl location. Make or buy offset dowls to correct this before putting the engine back together!
I don't think this would have been an issue with a .060-.100" overbore. There are a few larger overbore packages out there, but once you clear .060" Over, it's imperative to check for core shift!

Oh, and by the way, the lotus hyperpak was a factory one off racer. They did all kinds of stuff to that engine and head. The pistons were different as well. Just bolting on the parts that came with the option package does not a 200hp engine make...

The HP rating for the stock 225 mechanical cam engine across all years is the same. The changes were from measurement methodology. Gross and Net. Some of the smog equipment pulled the engine down, but the Gross was still the same.

CJ
 
slantzilla said:
I dunno. Mike J is running in the 14's with a 2bbl Slant and a box stock head in his Diplomat.
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I think Mike could run 14's with a stock slant in an M-1 tank.

With highway gears.

:)
 
Most, if not all of the info on that site is over 10 years old. It even has a reference to my turbo 65 Valiant, which was built in 1979. Everything on that car is obsolete, by todays standards.
 
I really need to update that page - probably when Geocities closes. Like Charlie said, I made it a long time ago.
 
slantzilla said:
My Slant Valiant has run 14 teens on motor only and 12.0 with a 150 shot on it.

I'm hoping the same motor will yield low 11's in my Daytona.
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You are able to do that consistently without breaking stuff? Insane but impressive.
 
On motor only it is bullet proof.

It is also bullet proof on nitrous unless I get greedy. When I get greedy it eats a piston or two.
 
slantzilla said:
On motor only it is bullet proof.

It is also bullet proof on nitrous unless I get greedy. When I get greedy it eats a piston or two.
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Ask him how he knows:toothy10:
How much was that that started eating pistons? 250 or 275???? Inquiring minds want to know................O:)
Hey D is the Datona going to Kerney?
Frank
 
Kearney is August 15 and 16th.

Yep, Nebraska. Somewhere out there in the middle. :-D

CJ
 
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