what are ideal compression #s for 1600

[spiderrey]

#s for a stock motor please.

[So Cal Mark]

fresh or worn out?

[spiderrey]

Both

[MNspiderman]

My version of ideal compression would be at least 12.5 burning E85 with the proper parts to support this bad behavior. But in the standard world between 9.5 and 10.5 is ideal for most applications. Factory compression just isn't fun enough.

[mdrburchette]

Are you talking compression #'s per cylinder or compression ratio? I checked the compression on my newly built 1608 a few weeks ago and got around 150 across the board.
My 72 with the built 1608 is showing comp ratio of 9.78 to 1.

[spiderrey]

Denise, you got it right. Compression #,s per cylinder. Not compression ratio. Were talking a stock motor.

[Trev124]

I think 150psi is abit low. Are you thinking of reconiditioning the engine? Recently I measured the compression ratio on my coupe turbo(cr 8.5:1) and they all measured around 165psi. I remember checking a car 1200cc car a few years ago and it had very good readings of 200plus on each cylinder.

[spiderrey]

thanx 4 the info

[ventura ace]

Reyy,
Keep in mind that compression measurements can be all over the map. The test can be affected by how strong the battery is, how good the starter motor is, temperature, and different types of compression gauges, and technique (like making sure that you're carbs and exhaust is wide open when you take the readings). My compression gauge has a length of hose that puts the check valve about 10" away from the spark plug hole, and gives much lower readings than other gauges that have the check valve closer to the spark plug hole. A reading of 150 on my gauge would read about 180 on Ron Luxmore's gauge. Both gauges are very repeatible, which is what's most important for compression gauge readings. The compression gauge is good for making comparison's but shouldn't be used as a calibrated numerical value. A leak down tester will give you a better quantitative picture of the condition of your engine (but doesn't give you the dynamics of compression while the engine is turning). Each tool has its merits.

Alvon

[engineerted]

Alvon is correct, It depends also on what camshafts and valve clearances you are running. One thing to look for is that the pressure values are with in 5 psi of each other. A single low cylinder may indicate a leaking valve, worn rings, or even blown headgasket.

Ted

[spiderrey]

Thanx for all the info. I wasnt asking for myself. But relaying info to someone who asked me. He had readings of 100- 140- 133- and 150, Not to good. Im gonna send him to this site next time we talk. He is working on his sisters spider, dosent have one himself.