New project. Is it rare???

4SPEED427 · A Poncho Legend!

RE: New project. Is it rare???

73SC · A Poncho Legend!

The engine is an LM1 that's clear. I think it first appeared in 1974 and was the replacement for the L48, Depending on year it was rated from 155 to 170 net HP. There is no way that the internals would be different for a Police car otherwise the RPO code would be a different code, it's not like GM was about to make two versions of the LM1, that's not how a mass production process works. If I'm not mistaken Norm worked in the Flint engine plant and he would be able to confirm.

It's a neat car but there is no evidence whatsoever to suggest it has a 9C1 package on it. That is not to say that it did not serve as a police car at some point in its life. Two door police cars were common when I was a boy and Pontiac did offer the LeMans Enforcer on the two door style in 76 & 77. Toronto Police detectives drive Pontiac G6 sedans and radar units use Pontiac Montanas and we know that police packages were not offered on either of those.

-- Edited by 73SC on Tuesday 15th of November 2011 11:40:04 PM

rabbit64cs · Canadian Poncho Superstar!

I think the hear say, was that this car was ordered with the Police Intercepter engine,, NOT that it was ordered as a police car.

and as pointed out , LM1 does not 'mean' you have a police car, just a 350 with a 4BBL..

correct ?

73SC · A Poncho Legend!

Since you put it that way Rog and since the 9C1 came with the LM1 as the only engine then yes it does have the same engine as the Nova police car. Got it now I think confuse

Big Steve · Addicted!

1975 2-door L6 48,103
Actually I don't believe that is true Roger. From the research I have done, The LM1 code is not the "Police engine", it was the go to engine that was used in the Police package.....And every other basic 350 option. It was their base model 350 for years, even in trucks. If you look at the Nova productions numbers I posted below (From novaresource.com) you will see that over 15000 Nova's were sold with that LM1 engine option. I think that maybe the claim was made, or could be made that this car has the same enging as the police package but does not have the police package itself. I don't think the engine makes the car rare, but the fact that it had that engine with the M20 trans, SS package, vinyl roof, hatchback, Etc. does.

1975 Nova production numbers
2-door V8 33,921
2-door hatchback L6 7,952
2-door hatchback V8 8,421
4-door L6 43,760
4-door V8 22,587
2-door Custom L6 7,214
2-door Custom V8 19,074
2-door Custom hatchback L6 3,812
2-door Custom hatchback V8 11,438
4-door Custom L6 8,959
4-door Custom V8 13,221
2-door LN L6 (Z11) 1,138
2-door LN V8 (Z11) 11,395
4-door LN L6 (Z11) 1,286
4-door LN V8 (Z11) 8,976
2-door Nova 'S' L6 16,655
2-door Nova 'S' V8 5,070
145-hp 350 (L65) 56,013
155-hp 350 (LM1) 15,290

Big Steve · Addicted!

Also this is off the Nasty Z28 web site. This site Also shows it in Camaro's back to 69.

The LM-1 is basically the same 350 that was found in every other Chevy car with a 350, i.e. it wasn't "special".
In 1977 the compression was 8.5:1, rated horsepower 170 @ 3800 rpm, Torque 270 ft/lbs. @ 2400 rpm.
In 1978 compression was lowered to 8.2:1. Due to a redesigned and less restrictive cool air ducting system, power was rated at 185 HP @ 4000 rpm, torque 280 ft/lbs @ 2400 rpm.

1977 - 1981 LM-1

Installed views: 1977 Z28 LM1 engine | 1980/81 LM1 w/ Cowl induction

1977 - 1981 Z28 Engine (350) - LM1, 170 - 190hp Block 3970010 2 bolt main
Crankshaft cast iron
Cylinder Head 333882 1.94/1.5" Valves, 75.47cc
Cam 14060651
Intake 14014440
RH Exhaust 346248
LH Exhaust 381863 could be 361863
Alternator:
Water Pump:

Cam specs: Hydraulic, Lift: .390/.410 (intake/exhaust), Duration: 310/320 (i/e), with 1.5 rockers.

Note: Horsepower varies from 1977 to 1981. The major engine components remained the same except as noted.

Carb: See year specific info
Distributor:See year specific info

1980 LM1
Courtesy of Matthew G. Thie.
The LM1 engine was the base Corvette engine. It was used in the Z28, because the original Z28 option meant Camaro with Corvette drivetrain. The main differences, that I am aware of, between this engine and the basic 350 are:

1.) The oil dipstick is on the other side of the engine. I believe this was done to fit the Corvette engine bay. This also caused a Camaro recall to fix a clearance problem with the dipstick tube rubbing against the Air Conditioning tubing, causing Freon loss. The oil pan is different because of the dipstick location.

2.) I was told the casting alloy of the block was changed to a high silicon alloy for longer life.

3.) The camshaft is very unconventional. In addition to having a higher lift on both intake and exhaust,than the standard 350, the timing is about 180 degrees off, compared to any other cam that I have seen. I have compared this cam to an aftermarket RV cam and it looks like the lobes are shifted by one position. When I asked Crane Cams Tech support for about this configuration, they said it would never work. It seems to be derived from the old mechanical lifter Z28 cam that was used in the original Z28 302 engine. (PN 3972178) The specifications that I have for the LM1 cam are:

Lift Intake .2600 Factory Service Manual
Lift Exhaust .2733 Factory Service Manual

These angles were measured from the cam from my LM1.
Lobe Separation 94.64 Deg.
.050 Duration 165.6 Deg. (Crank)
.050 Duration 154.4 Deg. (Crank)

I believe that this cam was designed to raise the dynamic compression ratio because this engine had a very low static compression ratio. (8.2)

4.) The 1980 LM1 was Blue.

Big Steve · Addicted!

Ha ha 73SC you beat me by 20 seconds. I think were all on the same page now. I love the information the Interweb has to offer. I remember having to look in books or go without this sort of info.

JJ · Guru

Good memories you sparked a few im my mind

Big Steve · Addicted!

Thats awesome. For me, it was my oldest brother in about 1977/78. I was 7 or 8. He bought a 1969 Z28, black, fibreglass flares on the back and N50 15's. I can still remember trying to see over the dash as he was runnin through the gears and getting 4th gear rubber. Haha.

MorePower · Poncho Master!

the orange one was a family members, sold it to my friend whom stillowns the car to this day, Very very rare true 76 SS orange with white interior, fact 4 sp,posi

the burgandy 78 Rally was mine I cloned into 76

the 74 SS was mine but I really loved the 5th generation muc more

Restore it...ya just dont see them anymore.

Id love to find a fact 75/76 SS.

blkl36 · Member

Old topic, but just for clerical and historic reasons, some facts, a 1977 "M20" is a Saginaw, Gm still used the M20 nomenclature in the build sheets etc., but the transmissions were indeed saginaw cast iron 4 speeds from factory.

73SC · A Poncho Legend!

Always interesting when a 10 year old thread resurfaces. In this case this was a very interesting and enjoyable read. Big Steve, can you complete the story with any updates?

Prefectca · Poncho Master!

Speaking of Novas, when I was in trade school in 1978 the teacher had a new Nova Rally. It was a sharp looking car, black with gold stripes and tan interior. In shop class one day he tossed me the keys to send me to the auto supply to get some gasket adhesive. Imagine my shock when I found it was an inline dix with three on the tree!

Paul

Big Steve · Addicted!

Lets see, update!!! I did not own the car very long. I had it advertised for sale and when the people got there from out of province they thought it was in worse condition then what I described. Now Im very careful as to accurately describe anything I have for sale because I hate confrontation and I hate when it happens to me. I think they just had stars in their eyes and werent listening to me. LOL but of course on that day It decided to run like a complete bag of crap and didnt have enough power to drive itself up on the trailer. So in trying to take a run at it it bottomed out and broke the exhaust off which then further jammed on the trailer. It was a total shit show from start to finish and I was lucky to get any money for it that day. It really was a cool interesting car with a good story and decent bones to rebuild it. Just maybe it didnt want to leave my yard LOL

DonSSDD · Canadian Poncho Superstar!

I believe the M20 code designates a manual transmission, I dont think it designated that the car had a Muncie or Saginaw or Borg Warner. A 75 Camaro had either a super t10 or a Saginaw depending on hp. Big Steve, did you ever look at the transmission in this car, Im betting it was a ST10 where it was a 4 barrel 350.

I just got married in 1975 and ordered a new 4 door Nova, options were a 350 2 barrel, T350, tinted glass, whitewalls, full wheel covers, and posi. It came standard with factory duals, Uniroyal radials, and a catalytic converter which frequently smelled of rotten egg gas.

It had a 100 mph speedo, buried the needle easily, then the needle would pass through the odometer and bury again. It was very good on gas and if you floored it hard would chirp both back tires at 60 mph if you passed over a little dip in the road. It worked very good, traded it in St. Johns NFld in 1980.

A friend. had a 75 SS 305 hatchback, a tan and yellow 2 tone. That was in St. Johns too.

-- Edited by DonSSDD on Sunday 14th of March 2021 10:18:24 AM

4SPEED427 · A Poncho Legend!

Exactly, M20 as an option code carried well past the last year of Muncie production.

On the 75 Nova with duals, wasn't it a single inlet dual outlet muffler? It wasn't a true dual system was it?

DonSSDD · Canadian Poncho Superstar!

Single in, dual out, 90 degrees behind the tires. It was a surprise when the car arrived after I ordered it. Not sure if it was a 350 thing or if the 305 had the duals too.

73SC · A Poncho Legend!

So we are straying a bit here but I have a lot of experience with this single exhaust system with twin tailpipes. I had this system on a 76 Firebird 350 , 77 Ventura 305 and 80 Grand Prix SJ 301. All of these cars had a muffler mounted cross-wise behind the differential. This installation permitted the muffler to have an outlet on each end which facilitated the twin tail pipes exiting behind rear wheels and in the case of the Firebird straight chromed tail pipes exiting at rear bumper on each side. This was in no way a dual exhaust system but was a dual tail pipe system. In 77 the return of the Z28, the system was a bit closer to duals as the single muffler was replaced with dual resonators aft of the catalytic converter with full dual tailpipes. Firebirds adopted this in 1978. I adopted this for my Firebird as well and that system could have been adopted for any Nova/Ventura, Firebird/Camaro and Grand Prix/Monte Carlo. In fact the Monte Carlo SS did get a version of this dual resonator system on the 83-88 run.

HK1837 · Addicted!

Just out of interest, the original LM1 was introduced at the start of 1969 model year and ran only until the end of 1969 calendar year in North America. It was basically the 1969 L48 engine with 76cc heads rather than 64cc fuelies. Everything else was the same except it had 2 bolt mains rather than 4 bolt, and the distributor was re-calibrated for the different compression ratio. It was the regular fuel version of the L48. It was 9.0:1, the L48 was quoted as 10.25:1. It was replaced for January 1969 by the L65, same engine as the LM1 but with a 2BBL carby (same carb as the 1969 235hp 327). We got it here in Australia in the automatic HT and HG GTS350 Monaro in 1969 and 1970.

The L48 continued for 1971 model year but with 76cc heads and dished pistons, so I'm not really sure why they re-introduced the LM1 as it is essentially the same thing. I've often wondered if the mid 70's LM1 was initially the California spec version of the L48 as from memory you couldn't get the L65 in CA??