A question for the slant six gurus

Joe12459

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My son's 81 Mirada was an original slant six car, but the previous owner somewhere along the line replaced the factory engine with a mid-sixties 170 slant six. The casting number, 2463230-2 seems to indicate post '64 production. The stamping, EW170R 2869 0075 is a little more obscure. The W might indicate a warranty block, and the E might indicate 1967 production year, but that's not my question. This engine runs very well, with an initial timing of 24 degrees BTDC and total mechanical advance of around 40 degrees at 3500 RPM. That seems like a lot of initial advance to me, but it runs/idles great. No ping/knock/detonation at any RPM/load. The engine has a '77 or so super six manifold, new BBD carb, and new electronic ignition with vacuum advance. Compression check shows 125 +- 2 PSI in all six cylinders. When I changed the timing chain, everything appeared factory, including the Teflon gear that came off in good shape, so I didn't degree the cam. I guess this is more just curiosity than anything, as the engine performs well. I'm just curious if anyone else runs these engines with that much initial advance. If anyone has more info about the engine numbers, that would be great, too!
 

slant6billy

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I have not dove into my 77 super 6 car yet. 25 or so years back my original 6 was a real dog until I put a little more timing into it. I don't think I got as much as 40° of timing, but I might have. It did not make any valve noise (more than usual). Just look at plug No4 and 5 after some decent driving on a hot day. You may want to get a hotter plug (cooler range) if it looks lean or baked. Can you adjust / advance any more on the Vac advance?
 

Aspen500

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The original timing spec for a mid '60's 170 is 2.5* BTDC. Unknown on total but for an 8.5:1 engine with a stock camshaft, 40 doesn't seem an unreasonable number. Question: Are you sure the balancer marking is in the right place (i.e. not slipped)?
With a rated 101hp and 145 ft lbs torque, more timing advance should help.
 

Joe12459

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I have not dove into my 77 super 6 car yet. 25 or so years back my original 6 was a real dog until I put a little more timing into it. I don't think I got as much as 40° of timing, but I might have. It did not make any valve noise (more than usual). Just look at plug No4 and 5 after some decent driving on a hot day. You may want to get a hotter plug (cooler range) if it looks lean or baked. Can you adjust / advance any more on the Vac advance?
The plugs all look good, no problem there. I can probably adjust the vacuum advance, but I don't think I need to. I didn't check total timing with the vacuum connected, but like I said, it runs great, stays cool, and doesn't knock/ping at all. Just a strange little engine.
 

Joe12459

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The original timing spec for a mid '60's 170 is 2.5* BTDC. Unknown on total but for an 8.5:1 engine with a stock camshaft, 40 doesn't seem an unreasonable number. Question: Are you sure the balancer marking is in the right place (i.e. not slipped)?
With a rated 101hp and 145 ft lbs torque, more timing advance should help.
The first thing I thought of was a slipped balancer, but when I did the timing chain, I verified that the marks were right at TDC. I not so surprised at the 40 degrees total timing as I am with how well it idles at 24 degrees initial advance. It idles right at 675 RPM, and makes plenty of vacuum. Just strange.
 
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BudW

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The engine number (EIN) of “EW 170 R 2869 0075” is defined as:
I could not find “EW”.
The only two choices in '69 are “PM” (Mound Rd.) or “PT” (Trenton) – so I suspect “PM” should be what it actually says (might want to clean a bit more and recheck). I have not seen a replacement engine mention anything about warranty on it, before. Once engine was built, it either went on train (or truck) to vehicle assembly plant or to parts warehouse. The Engine VIN was stamped at Vehicle assembly plant (or at repairing dealership).
The EIN (the above mentioned number) was stamped after engine passed final engine test.

"R" Regular fuel (ie: low compression).

“170” is the Cubic Inch.
Note: ’69 last year for the 170 ci. It was replaced in ’70 with the 198 ci version of /6.

“2869” is the date based off of the 10,000 day calendar Chrysler uses. This engine was assembled on June 5, 1969.

“0075” means the 75th 170ci engine built that day.

Note: with 55 ci difference between 170 and 225, I would be hesitant on putting a 170 ci engine back into a car (of mine). If it is already in a car then – no comment. If it was to come out, I would find a decent 225 short block (32%, or rounded to 1/3rd, more displacement) to go back into the car (my opinion, only).
BudW
 

Joe12459

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The engine number (EIN) of “EW 170 R 2869 0075” is defined as:
I could not find “EW”.
The only two choices in '69 are “PM” (Mound Rd.) or “PT” (Trenton) – so I suspect “PM” should be what it actually says (might want to clean a bit more and recheck). I have not seen a replacement engine mention anything about warranty on it, before. Once engine was built, it either went on train (or truck) to vehicle assembly plant or to parts warehouse. The Engine VIN was stamped at Vehicle assembly plant (or at repairing dealership).
The EIN (the above mentioned number) was stamped after engine passed final engine test.

"R" Regular fuel (ie: low compression).

“170” is the Cubic Inch.
Note: ’69 last year for the 170 ci. It was replaced in ’70 with the 198 ci version of /6.

“2869” is the date based off of the 10,000 day calendar Chrysler uses. This engine was assembled on June 5, 1969.

“0075” means the 75th 170ci engine built that day.

Note: with 55 ci difference between 170 and 225, I would be hesitant on putting a 170 ci engine back into a car (of mine). If it is already in a car then – no comment. If it was to come out, I would find a decent 225 short block (32%, or rounded to 1/3rd, more displacement) to go back into the car (my opinion, only).
BudW
Thanks for the info! It makes me feel better knowing when it was born. The EW is a mystery, but I cleaned it up and it is definitely EW.
The engine is currently in his car, and runs great, so it will stay for now. I have a 225 that I took out of my Mirada for the Hemi swap, so if I ever do replace it with another /6, I'll build that one. He was actually looking at a wrecked 06 Dakota V6 six speed RWD, so that drivetrain might make its way in as well. But like I said, right now it runs great, so it will stay. Thanks again for the info!
 

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the 170s are favored by the turbo/supercharger fans, which is an interesting idea. The shorter stroke makes them rev faster to redline than the 225s, and that kind of goes with high HP-low torque stickshift setup cars. I'm forgetting my /6 data... is it 4 main bearings the crank rides in? I know it is one or more short of what the normal straight six has which makes all slant sixes rev with less friction. The 170s moreso. Much has been written on this in the turbocharged slant 6 crowd.

Picture a twin turbo /6 Mirada with the two piece headers feeding a free revving 170 ahead of a 4speed overdrive manual gearbox... man that spells economy unless your foot is always in the gas :p
 

Joe12459

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the 170s are favored by the turbo/supercharger fans, which is an interesting idea. The shorter stroke makes them rev faster to redline than the 225s, and that kind of goes with high HP-low torque stickshift setup cars. I'm forgetting my /6 data... is it 4 main bearings the crank rides in? I know it is one or more short of what the normal straight six has which makes all slant sixes rev with less friction. The 170s moreso. Much has been written on this in the turbocharged slant 6 crowd.

Picture a twin turbo /6 Mirada with the two piece headers feeding a free revving 170 ahead of a 4speed overdrive manual gearbox... man that spells economy unless your foot is always in the gas :p
Hmm, I like building unique cars. I'll put this idea in his head as well, and see what he says. Thanks for the info!
 

Joe12459

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The engine number (EIN) of “EW 170 R 2869 0075” is defined as:
I could not find “EW”.
The only two choices in '69 are “PM” (Mound Rd.) or “PT” (Trenton) – so I suspect “PM” should be what it actually says (might want to clean a bit more and recheck). I have not seen a replacement engine mention anything about warranty on it, before. Once engine was built, it either went on train (or truck) to vehicle assembly plant or to parts warehouse. The Engine VIN was stamped at Vehicle assembly plant (or at repairing dealership).
The EIN (the above mentioned number) was stamped after engine passed final engine test.

"R" Regular fuel (ie: low compression).

“170” is the Cubic Inch.
Note: ’69 last year for the 170 ci. It was replaced in ’70 with the 198 ci version of /6.

“2869” is the date based off of the 10,000 day calendar Chrysler uses. This engine was assembled on June 5, 1969.

“0075” means the 75th 170ci engine built that day.

Note: with 55 ci difference between 170 and 225, I would be hesitant on putting a 170 ci engine back into a car (of mine). If it is already in a car then – no comment. If it was to come out, I would find a decent 225 short block (32%, or rounded to 1/3rd, more displacement) to go back into the car (my opinion, only).
BudW
Based on the following, do you think EW is 1969 year, Windsor plant?

Model Year
The following is a list of letter codes and their corresponding years. The year always precedes the engine displacement.
P = 1950
R = 1961
S = 1962
T = 1953
V = 1964
A = 1955
B = 1955
C = 1957
D = 1968
E = 1969
F = 1970
G = 1971
H = 1972
J = 1973
K or 4 = 1974
L or 5 = 1975
M or 6 = 1976
N or 7 = 1977

Assembly Plant Codes
K = Toluca
M or PM = Mound Bd.
MV or MN = Marysville
T or PT = Trenton
W = Windsor
 

FredMcJoe

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So I got curious about the bearing count, it's 4, and then I stumbled across this Stroke Your 170 Slant 6 write-up. Info rich article!
The guy built a dragster 210ci slant 6 from the short deck 170 block /6, with Chevy Vega pistons, and a crank from a 198 /6 and came out with a 9.2:1 CR high revving /6, 50 lbs lighter than an assembled 225.
Stroking the Slant 6
 

Joe12459

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So I got curious about the bearing count, it's 4, and then I stumbled across this Stroke Your 170 Slant 6 write-up. Info rich article!
The guy built a dragster 210ci slant 6 from the short deck 170 block /6, with Chevy Vega pistons, and a crank from a 198 /6 and came out with a 9.2:1 CR high revving /6, 50 lbs lighter than an assembled 225.
Stroking the Slant 6
Hmmm, ideas! Very interesting article.
 

BudW

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I had wondered about the "E" as in '69, but the data I looked up in - was my '69 data from Chrysler (see attached PDF file).

I could be mistaken, but I am 99.1% sure Chrysler did not make any engines in Windsor Canada, then or now.

The “E” is very plausible (for ’69) – as well as possibly having the “M” stamped upside down (which I have seen a few upside down stampings before – but not with a semi-reversible letter like M/W).

Note: I have looked up and identified a ton of Chrysler engines/transmissions over the years. The very first thing I do is locate the EIN (which you provided).
The second thing is to find the 10,000 date code – to determine what year book to grab for the rest of the details.

BudW

Note: there is a typo in the PDF file (from Chrysler printers). I wonder how long it will take someone to find it?
 

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Joe12459

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I had wondered about the "E" as in '69, but the data I looked up in - was my '69 data from Chrysler (see attached PDF file).

I could be mistaken, but I am 99.1% sure Chrysler did not make any engines in Windsor Canada, then or now.

The “E” is very plausible (for ’69) – as well as possibly having the “M” stamped upside down (which I have seen a few upside down stampings before – but not with a semi-reversible letter like M/W).

Note: I have looked up and identified a ton of Chrysler engines/transmissions over the years. The very first thing I do is locate the EIN (which you provided).
The second thing is to find the 10,000 date code – to determine what year book to grab for the rest of the details.

BudW

Note: there is a typo in the PDF file (from Chrysler printers). I wonder how long it will take someone to find it?
Thanks again for the info! I'm thinking the EW is a mis-stamp, as all of the other info makes sense.
 
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