Engine swap 170 to 225

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sibarra

sibarra

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Hey guys, trying to get some info/tips if anyone else has done something similar, but i blew the engine on my 68 dart it currently has a 170 but all i can find to keep it a six is the 225. Does anyone have any tips or advice? I have a mechanic friend that mentioned to check to see if some of the accessories from the 170 re compatible as well as the engine mounting points, if anyone can help me out i would really appreciate it!
 
It all cross fits. The 225 has more power and a bigger bore but everything swaps bewteen the /6's
 
Thanks!!! i assumed but just wanted to be sure, ill post pictures when i finish the swap!
 
I'm not sure, but I think most of the accessories would be compatible.

This article reinforces my feeling that they should be mostly compatible:

[ame]http://www.slantsix.org/articles/Slant%20Six%20Racing%20Manual.pdf[/ame]

If you go to/from or from to 67 or earlier/68 or later, then the crank counterbore changes from 1 1/4" to 1 1/2", which impacts your torque converter.

You may also want to post this question over on slantsix.org
 
Helped my friend do this swap, everything was the same. I think there was about a 15 year difference between the two motors so no worries.
 
I did one years ago and the only thing I changed(I think) was the longer fan belt
 
Try to stay from 68 and up. The 66-7 is a 2 year only trans and crank pilot
 
You will need to modify your exhaust to match the manifold. The 225 is 1" taller, so your head pipe will be 1" too short. My exhaust was horrible, so I ended up just having a new system bent up at the exhaust shop.
 
The hose from the water pump to the head is one inch longer on the 225, too, due to the block being taller.
 
Hey, welcome to FABO sibarra!! OK, point by point;

1) Yes, look for a '68 or later mill, or you will not be able to install it over the converter hub
2) Yes, you will have to lengthen/change your head-pipe.
3) Yes, the 225 is 1" taller than your 170, but inclined at 30deg. is about 3/4" vertical.
4) All slant sixes are the same 3.40" bore, there are (3) different strokes/displacements.
5) No, the small hub converter cannot be just swapped in to use a '67 and down mill.
6) No, the 170 was made w/the large hub bore '68-'70.
7) Get the whole 225 carb & all, your 170 carb may be smaller &/or jetted differently.
8 ) You may need to swap your oil pan/pick-up to the 225 depending on the donor vehicle.
9) The small hub bore cranks were made from '60-'67.
10) You may want to get the throttle-press. linkage if poss. if your ride is an auto.
11) Same as point #8 for your eng. mounts/brackets.
12) Yes, small changes are there w/ belts& hoses etc.

OK, now I would like you to help me out if you would. Post the block casting#'s below
the manifolds, and count the core-hole plugs as well, 3 or 5 on your orig. 170(if it is).
Also the stampings next to the alt. bracket on the deck pad, I would appreciate it,Thx!!
 
whitepunkonnitro said:
Same 3.44 bore...difference is in the stroke. 3.25 vs 4.25
Click to expand...
Right and wrong all at the same time,LOL!! You managed to get
not one of those specifications correct! You just quoted the bore of a 2.2L mopar, & the
strokes of a 327 chebby& 455 olds, are you running a fever?? :)

Oh, the (3) strokes are 3.125, 3.640, & 4.125 ..170...198...225.............:coffee2:
 
Killer6 said:
Right and wrong all at the same time,LOL!! You managed to get
not one of those specifications correct! You just quoted the bore of a 2.2L mopar, & the
strokes of a 327 chebby& 455 olds, are you running a fever?? :)

Oh, the (3) strokes are 3.125, 3.640, & 4.125 ..170...198...225.............:coffee2:
Click to expand...

He's new at this; give him some time... he'll get it right... :eek:ops:
 
Killer6 said:
Right and wrong all at the same time,LOL!! You managed to get
not one of those specifications correct! You just quoted the bore of a 2.2L mopar, & the
strokes of a 327 chebby& 455 olds, are you running a fever?? :)

Oh, the (3) strokes are 3.125, 3.640, & 4.125 ..170...198...225.............:coffee2:
Click to expand...

..uh...the sun was in my eyes?
 
I am looking for a 170 /6 engine. What's better a 170 with the small hub bore cranks or larger hub bores? My slant six goal is to find one that drinks the least amount of fuel at low idle.
 
Sedanman said:
Try to stay from 68 and up.
Click to expand...

That's his only option if he's got an automatic transmission he wants to keep and doesn't want to have a custom torque converter made.

The 66-7 is a 2 year only trans and crank pilot
Click to expand...

No, it isn't. The smaller torque converter nose and matching smaller crank counterbore is '60-'67.
 
Feather Duster Dan said:
My slant six goal is to find one that drinks the least amount of fuel at low idle.
Click to expand...

I'm sure that's the first time I've ever seen that as a goal. How come? How are you using your car that it spends most of its time at a low idle?

(Also, if your present carburetor works well, it will keep working fine on a 225).
 
slantsixdan said:
I'm sure that's the first time I've ever seen that as a goal. How come? How are you using your car that it spends most of its time at a low idle?

(Also, if your present carburetor works well, it will keep working fine on a 225).
Click to expand...

Good question and I've notice that too!

I plan on running the engine @ parked more often than driving it around (5 to 15 minute warm-ups, very short commutes, and heater for car camping the cold winter nights).

I believe the 170 will be the best application for that, what's your opinion between 170, 198, 225?

Should I go for a 170 with the small or large hub bore, what are the pros and cons between the two versions?

Should I go for the 1 or 2 barrel carb?

Looking for a top speed of 55 mph and most of my driving is 45 mph, the min. legal speed on most Interstates and Freeways?

Currently, I have a 225 (needs engine & firewall harness plus tune-up, carb rebuilt) with hydraulic lifters and 2 barrel carb. with an A-833 OD. Thanks, Dan
 
Last edited:
I have a 225 (needs engine & firewall harness plus tune-up, carb rebuilt) with hydraulic lifters and 2 barrel carb. with an A-833 OD
Click to expand...

That setup, with the HEI upgrade including a distributor carefully curved (by DusterIdiot over on slantsix.org ) for your exact needs, and a thoughtfully-selected and -tuned carb, should do very well for the service you describe. There will not be a big difference in fuel consumption at low idle between a 170 and a 225. Those "warm-ups" and short commutes will result in poor gas mileage and quickly-dirtied engine oil no matter what.
 
slantsixdan said:
That setup, with the HEI upgrade including a distributor carefully curved (by DusterIdiot over on slantsix.org ) for your exact needs, and a thoughtfully-selected and -tuned carb, should do very well for the service you describe. There will not be a big difference in fuel consumption at low idle between a 170 and a 225. Those "warm-ups" and short commutes will result in poor gas mileage and quickly-dirtied engine oil no matter what.
Click to expand...

I like to measure my fuel consumption gallons/hour instead of mpg, more accurate for my application. Will there be a big difference in fuel consumption between a 170 & 225 if I safely ran the slant 6, lets say 8 hours/night, 30 days/month in the middle of winter in North Dakota?
 
Sorry, dude, this question's just skidded off Random Road and into the Field of Weird Dreams. From over here on solid ground, the answer looks like this: Use the right tool for the job. That's a late(r) model car with a fuel-injected 4-cylinder engine.
 
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