SR code SF code 455's whats the Difference

Whats the derference between the SR code 455's and the SF code 455's, just looking for info

 

'70 wildcat convertible

I'm not sure the difference between the engines. I know the SF code engine is rated at 370 horse and 510 lb/ft of torque. I anticipate the engines are relatively the same internally.

I note you have a '70 Wildcat convertible you are working on. I know of a fellow in Calgary, Alberta who has a complete '70 Wildcat convertible for sale. $350.00 for the whole car. It's rough but the complete powertrain is there (SF code 455/turbo 400), power top is there but the body is quite rough on the front end and passenger rear quarter. Let me know if you want any more information on the car.

 

The stamp. I believe that even the stud for the big car brace to the passenger exhaust manifold is there but just not used on the SR. If it is not that is an external difference. Maybe someone with a 70 455 GS car that for sure has never been apart cna confirm that big car stud is in place.

 

Just to clarify Jim's post, the is NO functional difference whatsoever between an SF and an SR 1970 Buick 455. Numbers lie.

PS no studded exhaust bolts on my 2nd owner 03D Flint-built 70 non-Stage SR GS 455

 

motor codes

So th SF code just Identifies the motor as being a Staged 1 GS motor or not but basiclly they are the same functionly, one means it came out of a GS and the other code means it came out of a Electra, Rivi, or Wildcat , does that sound right.

 

So this is how this should look, is this correct?

V-8 455 4bbl SF ?????(Wildcat,Electra, Rivi ect...)
V-8 455 4bbl SR (GS455)
V-8 455 4bbl GS Stage 1 SS

What are the differences of these three?????? or am I asking too much......LOL o No: o No: :laugh: :laugh:

 

The top two are the same and the third has the stage one add ons listed in a ton of posts and pictured in many.

 

From Team Buick Web Page 1970 Buick Engine Speifications<o></o>
<o></o>
<o></o>
Engine code # Cyl. CID HORSE POWER COMP>RATIO CARB><o></o>
<o></o>
SF... 8... 455... 370... 10.5:1... 4BC<o></o>
SS.... 8 .......455 ........360 ........10.5:1.... 4BC<o></o>
SR... 8 ..455 ....350 ...10.0:1 ...4BC

I haven't found what the physical difference is, still looking..
garyesbuick

 

Thsoe horsepower rating numbers are artificial. They were moved about based on the weight of the intended vehicle and not the actual output of the engine.

 

Don't be surprised if you look deeper you see more differences, such as in calibration.

Jets, primary metering rods, secondary metering rods, rod hanger, ignition timing curve are all fair game for differences between different coded engines from a calibration standpoint even if the hard parts are common. This happens frequently due to significant weight differences between platforms (GS compared to Electra, for instance).

Devon

 

Not a thing, apart from stamped engine code.
Both engines are identicle.

 

The main differences between the SR & SF motors was they used different fuel pumps, and if put in a Riviera it had no fuel pump. Plus if used in a Riv the SF motors had a different oil pan and oil pressure switch.

What you guys aren't taking into consideration is there were 4 different versions of the "SR" motor and 6 different versions of the "SF" motor.

These motors had different designations due to the way they were fitted out, ie AC vs non-Ac, stick vs auto, Riviera vs big car & a-body. The motors came to final assembly with all these pieces on them, therefore Buick needed a way to tell them all apart.
Duane

 

Thanks for this. I figured there must be some differentiation required for a good reason otherwise Buick would not have ever used different stamps when commonality would have saved $$$.

Devon

 

Ok tell us the difference between a SF in an 70 Estate Wagon with AC (or without) and a SR in a 70 GS with AC.

 

Not even a "please" Jim? :laugh:

Devon

 

For example, maybe a SR could be drilled for the z bar ball stud from the factory? I cannot think of a need for this on a SF application. It may be needed on a SR.

 

Yeah really.

I am reading all this out of the factory "1970 Buick Engines Factory #36" booklet and it shows all the part numbers/paint stripe information used for all the parts that made up the engine sub-assembly. (However this book does not list any parts put on the motors at final assembly.)

as far as "SR" motors there was a stick with AC, stick without AC, auto with AC, and auto without AC. (4 different versions)

..................and again if you are asking about the differences between the SR & SF motors the book shows they used different fuel pumps.

If you want to know all the specific parts each motor used sorry but I am not taking the time to do it.
Duane

PS. If you dig out your 70 assembly manual you can see the different SR versions on page 6-4.3 They have manufacturer codes of "PA" "PB" "PC" & "PD".................and this is why Buick put a sticker on the driverside valve cover to easily tell the different variations apart. The last thing they wanted to do was pay to rip a motor out of a car that was just assembled.:laugh:

PSS. the "SF" motors came in the following configurations
Auto with AC, Auto without AC, Stick with AC, Stick without AC,

and for the Rivieras Auto with AC, and Auto without AC.

 

Thanks again for this. I was surprised (not so surprised now) that so little of this detail had come up in some searching I did today out of curiosity. Don't own a '70, don't own a '70 manual, which was the first place I would have looked.

Devon

 

Devon,
After looking at the book further it lists the "SR" & "SF" as using different camshafts also. I guess they needed to change the cam due to the different weight of the cars.

I never cared about any of this because it never came up on the "show field".:laugh: We had enough to deal with checking over the cars, let alone worrying about engine internals, but I saw the thread and started to wonder.
Duane