two questions - compression and speedometer
Thread Starter
Intermediate
Joined: Oct 2002
Posts: 47
Likes: 0
From: laurel md
two questions - compression and speedometer
I have two quick questions -
1) I recently had a compression test done on my 86 vette, stock 350 engine , 140,000 miles and I've heard widely different opinions on what the compression should be. Does anyone know?
2) This may be the dumb question of the month (or year), but I've looked on the site and haven't seen anything about the speedoeiter. Mine only goes up to 85 MPH. Do I need a mod to get it to read higher?
1) I recently had a compression test done on my 86 vette, stock 350 engine , 140,000 miles and I've heard widely different opinions on what the compression should be. Does anyone know?
2) This may be the dumb question of the month (or year), but I've looked on the site and haven't seen anything about the speedoeiter. Mine only goes up to 85 MPH. Do I need a mod to get it to read higher?
Race Director
Joined: May 2001
Posts: 14,165
Likes: 9
Re: two questions - compression and speedometer (lfmn16)
Compression will vary, but 100-140 should be fairly healthy. What you'll be looking for more so than the numbers will be how close the numbers are to each other. Are they all pretty much within 10?
A leakdown test is actually a better way of determining the overall health of the motor.
As for the speedo, I think that was some kind of federally mandated bullpoopie. Something like "even though the car goes faster than 85, we'll only allow the speedo to register 85 and thus people won't drive that fast" More high quality thinking from up above. I don't know what you can do about it though, I know mine will register 254 before it starts counting what would be negative. :blueangel:
[Modified by Nathan Plemons, 6:52 PM 10/31/2002]
A leakdown test is actually a better way of determining the overall health of the motor.
As for the speedo, I think that was some kind of federally mandated bullpoopie. Something like "even though the car goes faster than 85, we'll only allow the speedo to register 85 and thus people won't drive that fast" More high quality thinking from up above. I don't know what you can do about it though, I know mine will register 254 before it starts counting what would be negative. :blueangel:
[Modified by Nathan Plemons, 6:52 PM 10/31/2002]
Thread Starter
Intermediate
Joined: Oct 2002
Posts: 47
Likes: 0
From: laurel md
Re: two questions - compression and speedometer (Nathan Plemons)
Thanks for the info. All eight cylinders registered between 149 and 151. When I bought the car, my mechanic suggested that I make the sale of the car conditional on passing the compression test and MD state inspection. Passed compression, but it would have cost me $1200 to get it through inspection. Fortunately the dealer honored the agreement (even though it didn't cost him $1200) and fixed everything for the inspection. He even fixed a broken universal which was not part of the agreement. Cooper Corvettes in Triangle Virgina.
