225 Rebuild from scratch

-
Deemo

Deemo

Well-Known Member
Joined
Mar 27, 2017
Messages
439
Reaction score
209
Location
Tennessee
is there a book or link to where I can get some numbers and info on how to rebuild/spice up a 225 slant??? Only found one site online but need to fill my head with as much info as possible before I go buying parts or modifying anything. Casting number is 225 2 14 and I'm super excited to yank that ol 170 out and slap this thing in. Maybe turbo as well. But first want the basics. A strong reliable engine built to specs off of proven engines. This is where I'm at right now. And the misses ain't too happy considering I have an engine I. The living room.

IMG_0949.JPG
 
If you really intend to add a turbo later, then the build of the bottom end is important. Use of the right pistons (I'd avoid the stock cast ones) is the most critical item, but it all depends on how much boost you will be adding as to what else to do to rods, crank, etc. If you stick with 7-8 psi of boost max then it is not too big a deal; if you go much beyond that, then things are going to have to be strengthened up.
 
I do have a factory service manual. Was wondering if the factory crank and rods from a 66 225 would be suffice to hold 9-12 lbs boots. But this isn't about that ATM, I want to run it first before I go that far. My main concern in this is how strong are the factory rods and crank. Slantsix.org says crank is pretty strong. But I can't find anything about the rods. They also say that the 70 something and older heads won't flow like the newer ones. I just want to build a strong reliable daily driver. That if I do decide on adding boost or whatever to it I can safely do so
 
I am not the guy to speak to those rods.... Does the 9-12 psi boost get you to a goal that 8 psi of boost does not? 8 psi will be a nice improvement and will stay in the realm of solid daily driver. Somewhere in the 9-10+ range, the torque starts to really step up.

If 'twer me, I would go with stock parts (rods/crank) for now, and get it running well with static compression ratio of around 8:1, and then go limited boost later if I wanted. Maybe polish the rod beams and shot peen them.

And I am not up to speed on the /6 pistons..... hypers for the /6 aren't popping off of the internet like for V8's, except for the KB 2.2 ones that you would use with the longer 170 rods. See here:
Stroking the Slant 6

So that leaves the Wiseco forged pistons but now we are getting into budget questions.
 
Yes, now I saw the 2.2 pistons and use the 170 rods. Then it becomes a "stroker" somewhat of I read that correctly. Daily driver is my main goal as my 170 that's in there now is reliable as hell. I pick my kids up in that thing every day with no issues. 3 schools to go to and not once single miss. Budget is something of an issue, but I know mopar. Budget 100 bucks, then double it because it's a mopar. I saw a lot of pricey builds over there on slantsix.org. Was just wondering if a slight over bore, mill the head and deck to flat, and factory internals would be suffice. I don't have a lot of money and want the most bang for my buck without having to worry
 
OK, well since budget and reliability are the keys for you, then it is time to drop the turbo upgrades and go basic. Yes a simple bore with stock cast pistons like Sealed Power 244NP types, and then mill the head and block a bunch to get the compression ratio up. Then put in a decent torque cam and go with a 2 BBL or small 4 BBL carb and I think you will be pretty happy with it as a first step. The stock bottom end will be fine at that level.

Part of what is holding back torque the low actual compression ratio; it is in the under 8:1 range stock and goes a bit lower with a later, thicker head gasket. Milling the head and block a combination of .120" will get you up into the high 8's to 9 static CR range. Once you get there, that will be a very decent street compression ratio and you can put in a slightly bigger cam to take better advantage of a larger carb without dropping the low RPM torque into the toilet.

So for a streeter, and daily driver, and a /6 with a limited breathing head, low RPM torque is the thing to seek; that is where I would head with no question.

And FYI, if you mill the head/block that amount then you may want shorter push rods. And you need to know the cam so that you will be able to make sure that the valves do not hit the pistons with the shorter deck height from the milling. So some planning is needed if you do this much milling.

Pay the $$ for a good timing chain. The standard ones tend to stretch and retard the timing. I'd also figure out the best way to advance the cam a few degrees.

BTW, once you settle on what you can do to the block and head as far as milling, and pick a carb, then I would steer you towards Doug Dutra (Dr Dodge on slantsix.org)

Just don't go too big on carb or cam.

What kind of trans do you have? And do you have a head for that block?
 
I don't have a cam, but I do have the whole engine. I mean every bit and bolt. It was burning oil from #2 piston. Carbon built up on and they tore it apart years ago. Just a regular ol /6 with single barrel carb. The head is the original 66 so it does have that little dime piece on the underside of the head in the chamber across from the spark plug hole. I've never built a /6 and really want this thing stout, reliable, and upgradable. I'm searching for the super six intake when I get some cash along with a 2 barrel carb. Maybe 4 if I have the cash. But for now single with the crummy factory intake.

I've seen Dutra"s work and engine he's done. They are fantastic but I don't have that kind of cash to throw around. Here's the block as it sits now. Already cleaned up, needs honed and have painted it the mopar red. I have a book from 66 with all the information. Factory service manual. With three kids, and everything else it's hard to do a nice build.

IMG_0957.JPG


IMG_0956.JPG
 
Doug will get you hooked up with a better than stock cam at a decent price, and will know things like lift and piston clearance with so much milling, etc. He works through a cam grinder and puts a modest mark up on it but not much. It is worth the small price to get his expertise in the matter. Also, he regrinds lifters himself so you can get his reground lifters cheap. So don't bypass that idea because he also does higher $$ work; it will be worth your while IMHO.

He reworked an oil pump for my /6 at a VERY reasonable price, and I am glad for that as the pump gears can be a weak point. And that is another reason to go with his cams.... some of the cams are hard on the oil pump gear IIRC, and he will make sure things are OK there. (If that gear fails, so does your oil pressure.....)

The intakes and carbs you are pursuing are good. Just keep in mind that to use a 4 BBL effectively, you need a cam to work with it. Again, just don't go too big or you will hurt daily driver performance.... go for low RPM torque, not high RPM HP. That mistake gets made over an over on all engine sizes.

IMHO, you are set to start... just add $$ LOL

May I ask what part of TN are you in?
 
Look up Oregon cam grinders, the can get you a regrind for like 80 bucks in a nice grind. Way cheaper than a new cam, and send them your lifters and they will reface them good as new for like a buck a piece. That's about $100 saved right there. Draw through turbos are the easiest to do, just fanagle up the turbo to the stock intake (blow it straight down in for distribution equality) and mount the carb off the turbo intake via a "power elbow' or a 90. Keep 90 to intake as short and compact as possible as the turbo will chop up the atomization pretty good buT the longer it's in transit, the worse it will work. This crude method allows you to use a standard carb with no mods. Any other na build will really work better with a decked block, cut up to .100 off if you can. Turbo can use stock lo comp deck height. Use a J pipe (my Peesh pipe?) Off exhaust and rest turbo right on top or high as possible to get carb mounting access, like it was made there. A good Carter Cortez side draft would work great buy those are hard to find.
 
On that note, I'm In middle Tennessee. About 30 mins south of Murfreesboro. I have a set of lifters that have only 9k miles on them. Been saving those for this occasion. They should work wonderfully And I'll look into the reground cams. That sounds like more to price range.
 
Deemo, If you want to talk to slant six racers in person, there are two slant six races in your area.
Knoxville Dragway: Knoxville TN 8/11 & 8/12
Mountain Park Dragway: Clay City KY 9/9 & 9/10 2017
 
Deemo said:
On that note, I'm In middle Tennessee. About 30 mins south of Murfreesboro. I have a set of lifters that have only 9k miles on them. Been saving those for this occasion. They should work wonderfully And I'll look into the reground cams. That sounds like more to price range.
Click to expand...
Oooops.. no, no, and no! You should never put used lifters with a new cam! They have already been worn in with the original cam's lobes and will chew up one or more of a new cam's lobes with a nearly 100% probability. You can only use these lifters if the bottom surfaces are reground fresh.
 
nm9stheham said:
Oooops.. no, no, and no! You should never put used lifters with a new cam! They have already been worn in with the original cam's lobes and will chew up one or more of a new cam's lobes with a nearly 100% probability. You can only use these lifters if the bottom surfaces are reground fresh.
Click to expand...

My mistake. Not the lifters :(. The rocker arm!!! Lol. Yeah. I learned that mistake when I was 17 in my fairlane. First time I ever done that and surely will be the last
 
You must log in or register to reply here.
-

Back
Top