74 225 slant 6 options

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74Dart_Girl

74Dart_Girl

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so.... Im in the process of configuring what I want to do with this engine.. Im not planning on ever replacing it with anything else (all numbers in this car match and im quite happy with the fuel economy it provides me as a daily driver) but would like to know what upgrade options there are avaliable for this.. Ive heard rumours about being able to upgrade its hp fair bit with the a few replacement parts here and there ( a whopping 105 hp currently, damned emissions anyways)... I will be pulling the engine for cleaning/painting and head gasket repair in the future so would like to know what I could do while the slant is out and able to be torn apart..

Thanks again! :D
 
well.....the slant 6's are at the very bottom of available engines. In my opinion a "numbers matching" slant 6 will never make any difference in the value of any slant car (no offense to anyone), however, there are many things you can do to get decent power of them. a set of headers for starters, a super six 2 barrel swap or even a 4 barrel intake, ignition upgrades etc etc. there are a ton of threads about upgrading and improving the /6.
 
73AbodEE said:
well.....the slant 6 cars are at the very bottom of engine options. In my opinion a "numbers matching" slant 6 will never make any difference in the value of any slant car (no offense to anyone), however, there are many things you can do to get decent power of them. a set of headers for starters, a super six 2 barrel swap or even a 4 barrel intake, ignition upgrades etc etc. there are a ton of threads about upgrading and improving the /6.
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hmm good ideas, Ill take a snoop about and see what additional info I can find :)
 
best bang for your buck is when you pull the head to have the head milled about .090"... then have new exhaust seats installed, also new guides...

then upgrade the intake to a super six intake and 2 barrel carb off of a 318...

lastly upgrade the exhaust to a 2.25" from the exhaust manifold back... with new muffler...
 
Why new exhaust seats? Aren't they hardened in 1974? If they are still good, leave them alone. That will be money better spent somewhere else. The super six upgrade is a good one. Depending on how far you want to go, milling the head for an increase in compression is also a good idea.....IF you want to go that far.

Before "I" did any mods, I would make SURE what's there now is in top tune and running condition. Start with a compression test. No sense spending money on exterior bolt ons if the inside is worn out. Remove the PCV valve while running. Plug the PCV valve with your finger. Rev the engine gently and take not of how much blowby comes out of the valve cover. If it's a lot, you've got some worn rings. Measure the engine's vacuum signal with a gauge. It should be over 16 Hg...closer to 20. The higher, the better shape it's in. You don't want to spend a wad of dough on a wore out POS.

Slant 6 or not, the car is only original ONE TIME. Some may say it's not worth much, but if it's original, that's worth something. Slants get thrown in the ditch all the time so they are pretty cheap and plentiful. If you're concerned about the original engine, pull it out and find another slant to warm up. At least that way, you'll still have old faithful waiting in the wings.

Just food for thought. If you do decide to mod what's there, just make sure it's not worn slap the hell out as described above before you drop a lotta coin on it. Just my 2 cents.
 
SS is right...

get a new set of autolight 66 plugs REMOVE THE WASHERS!!! and gap to .035"... go to a 65 if you mill the head...

http://www.summitracing.com/parts/FRM-66/

go to summit and buy a CH410 Brass terminal cap

http://www.summitracing.com/parts/SMP-CH410/

there are some 8.5mm wires on ebay for 40 bucks,

http://www.ebay.com/itm/MAXX-515K-8...r_Truck_Parts_Accessories&hash=item3cc78b7d1c

great if you are running a blaster II coil (which you should, or any of the other HO coils)

http://www.summitracing.com/parts/MSD-8202/
http://www.forabodiesonly.com/mopar...ich you should, or any of the other HO coils)
still need to get a new air filter and do all of the adjustments... but these should help!
 
Johnny Dart said:
805moparkid said:
SS is right...

get a new set of autolight 66 plugs REMOVE THE WASHERS!!! and gap to .035"... go to a 65 if you mill the head...

Slow down trigger.
Are you sure he has the drool tube head ?
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pretty sure drools went away in 76 but being im on my GF's computer (mine died) i cant look up my chart... but thats a good point...

to OP, is there an aluminum tube around the plug? or is it just the cylinder head?
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74Dart_Girl said:
805moparkid said:
Yes there is an aluminum tube around the plug...
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Ok....They are known as "drool tubes". That means you have a drool tube cylinder head. When you install new spark plugs you take the washers off.
The drool tubes act as the washer,when installed.

You will also notice some round rubber seals around the drool tubes. These seal the tubes to the cylinder head. When you get new plugs,get a set of new seals.
Felpro part# ES12794
Click to expand...
 
All good advice above. Certainly check the blow-by. Another way to check the compression is to turn the crankshaft over by hand. If you feel each piston compress and hold pressure like a spring (5+ sec), that is a sign of a fine engine. You should feel 3 pulses per revolution. You can pull on the alternator belt to turn it. If so, I wouldn't even pull the head unless you know you have a leak or really want to mill the head for better compression. Has someone suggested your head gasket is bad, and if so, why?

Changing to HEI ignition would be my next choice. I think you have electronic ignition in 1974, so fairly easy.
 
BillGrissom said:
All good advice above. Certainly check the blow-by. Another way to check the compression is to turn the crankshaft over by hand. If you feel each piston compress and hold pressure like a spring (5+ sec), that is a sign of a fine engine. You should feel 3 pulses per revolution. You can pull on the alternator belt to turn it. If so, I wouldn't even pull the head unless you know you have a leak or really want to mill the head for better compression. Has someone suggested your head gasket is bad, and if so, why?

Changing to HEI ignition would be my next choice. I think you have electronic ignition in 1974, so fairly easy.
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no reason to go to HEI with it already having Mopar electronic... just upgrade to an orange box and a New Coil (MSD, Pertonix, etc...)

dont know where the head gasket thing started....
 
805moparkid said:
no reason to go to HEI with it already having Mopar electronic... just upgrade to an orange box and a New Coil (MSD, Pertonix, etc...)

dont know where the head gasket thing started....
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X2..i dont know how it got here, the OP just wanted advice on simple upgrades
 
I am in the same position as the original poster. I don't really give a hoot about the matching numbers, a slant 6 is what I have in my Duster and I can't quite afford going to a nice 340 or 360 built. Anyway, where can I acquire this super 6 upgrade? I also noticed a header on JEGs for the dodge I6--nearly $700! Ouch.
 
MLC Dodge said:
I am in the same position as the original poster. I don't really give a hoot about the matching numbers, a slant 6 is what I have in my Duster and I can't quite afford going to a nice 340 or 360 built. Anyway, where can I acquire this super 6 upgrade? I also noticed a header on JEGs for the dodge I6--nearly $700! Ouch.
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i just picked up a second set on here for 250 bucks... having them both coated so they dont rust out lol...

for a mild slant a stock mani will be fine...
 
now that I know I have the drool tube heads, to do a compression test with a compression tester (The compression tester has a rubber gasket hence the inquisitiveness), do I leave the aluminum sleeves in ? take them out and attempt to line it up inside? is there some "mopar' tool that will assist ? or is it just not feasible?
 
You leave the tubes in. The spark plugs hole them in. When using a tester it will hold the tubes in as well.
 
Wow, a daily driver, that's impressive, I have the ol 225 in my 74 duster and I hear you on the lack of power front. I live about 20 mins away from 74 dart girl, let me know how your upgrades go!
 
225 Duster said:
Wow, a daily driver, that's impressive, I have the ol 225 in my 74 duster and I hear you on the lack of power front. I live about 20 mins away from 74 dart girl, let me know how your upgrades go!
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Very cool! not too many people from our neck of the woods on here, glad to see another 74.. The duster is a nice car :).



So the compression test is completed! Did a wet and dry.. here are the results:

(1) dry test result: 145 (1) wet test result: 175
(2) dry test result: 145 (2) wet test result: 155
(3) dry test result: 155 (3) wet test result: 174
(4) dry test result: 150 (4) wet test result: 165
(5) dry test result: 150 (5) wet test result: 160
(6) dry test result: 140 (6) wet test result: 155

Oh and other news! no new head gasket needed! Cleaned the engine off so you could eat off of it and replaced the spark plug tube gaskets and VOILA no oil so far, hasnt been driven on the road yet but im pretty confident its fixed.... yippee!:toothy8:
 
Skip the Autolite plugs (Chinese junk). Tune-up parts and technique suggestions, including spark plugs, are in this thread. The engine may well be overdue for a valve adjustment, too. Carburetor operation and repair manuals and links to training movies and carb repair/modification threads are posted here for free download.

Once you've got it tuned and adjusted so it's running its best, there are lots of upgrade options. You'll hear the name "Clifford" come up, but be very careful before you decide to spend any money with Clifford. They have a long and ugly reputation for being a bunch of clowns; see for example here, here, here, here, and here. Much of what they sell is inaccurately described, and a lot of it is not even slightly cost-effective. The good news is that you don't need to go to Clifford to get hot rod parts for slant-6s; there are lots of other, better options. See for example Dutra Duals and header options discussed in this thread and this one, Erson custom cams, HEI ignition upgrade, Mike Jeffreys windage trays, Hurricane intakes, other exotic intakes. Hi-perf engine buildup here, high-perf parts and build info here.
 
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