oil pres question -305 v8

[jim83]

Oil Pressure question- I have an 83 cutlass supreme with the olds 305 v8. Car is low milage at 65k - one family owner since new.
Car has the stock rally pack gauges in good working order. I use 10/40 valvoline max life oil.

Fully warmed up what should the oil pres be @ 800 rpm in gear, brake on - I have 28-30
Same question going down the road I have 45-47

Seems very sensitive to idle speed in gear- 650 rpm win gear will drop it to around 25

Jumps right up when brake off & driving
All above with water temp @ 195
Normal or?

 

[Gonzo1970]

Once the engine is warmed up, 20 psi at idle and 40 to 50 at speed.
A general rule of thumb is 10 psi for each 1000 rpm.
A cold engine will read higher.

 

[fleming442]

It's fine.

 

[jim83]

Figured as much, but surprised as to how how much of a difference it makes at idle between 650 in gear hot & 75o-800
Really drops off at 650- still safe though.

My Dad bought this car new, the only criteria was the v8 & it had to have gauges. What do you know it also had the touring suspension!

Slightly off the subject- replacing the exhaust - stock system - the Walker catalog only goes back to 84 & call to them didn't help.
is there any diff between the long pipe from the cat to the muffler between those years- 83 & 84?

thanks guys!

 

[TURNA]

The real problem you have is the Olds 305, since they never made them!!!

 

[jim83]

305 , 307 or whatever, the parts stores list it as a 305, Anyway its a Y code & not the gm corporate chevy that they put in everything in that era.

 

[TURNA]

305 Chevy and a 307 Olds are 2 completely different engines with nothing interchangeable.

So what ever parts stores you are going to STOP going to them!!!!!

 

[pontiacgp]

305 , 307 or whatever, the parts stores list it as a 305, Anyway its a Y code & not the gm corporate chevy that they put in everything in that era.

are you sure they don't list them both as a 5 litre?

 

[MrSony]

Both are 5.0 liters, parts stores will list them as VIN Y (or VIN 9 for the roller engine) for the 307, or VIN 7 or H for the 305. As far as I know, no 78-88 american cutlass' got the 305, always the 307, in terms of the 5.0 liters.
The engines however are %110 different. They share nothing in terms of parts or architecture, except the cap rotor and coils. Probably plug wires. Probably not spark plugs. Either way, your oil pressure is fine. Anyone with a 231 would be jealous.

 

[DRIVEN]

As far as I know, no 78-88 american cutlass' got the 305, always the 307, in terms of the 5.0 liters.

Close. '78-'79 for sure did. Maybe '80 too. Either way, OP's oil pressure is great.
My recommendation on exhaust is to order the pieces for a GN from Rockauto and let an exhaust shop mate it to the Olds headpipe. It fits in stock location, doesn't hang low, and sounds good without being too loud. Plus the tailpipes come out in the proper Olds neighborhood.