swappedsieg

I have a fully built ls. B18b with 82mm wiesco postons. Eagle esp h beam rods. Full brian crower valve traina.....yada yada yada. Andyways the motor has about 5k miles since the build. Runs like a champ. Pulls hard. Did a comoressuon test and im getting 160 across the board with throttle at wot on fully warmed up engine. Comoression ratio is 9.8:1.... numbers seem low to me. But like I said runs strooonnngggfgf. Should I boost with the numbers. Its making 162 whp. Im just scared my rings wont hold up. I dont know why the numbers are so low. Any idea

dcmatt

iTrader: (7)

Not sure if it should be a lil higher or not but the fact that you have the same reading across the board is a good sign. How many miles? Newly rebuilt engines will pick up a lil compressiin as the rings get fully seated.

blackeg

compression is a bit low but as mentioned even is good. do a leakdown if you are worried further.

if you are making 162whp on a nonvtec at 9.8:1 compression im sure you have an aftermarket cam which likely is bleeding out some compression due to overlap. what cam/cam gear settings are you running

swappedsieg

Never thought that the cams would cause low numbers. Im running brian crower stage 2 n/a cams. Aem 6 bolt cam gears exits retarded 2. And intake is at zero. Thats what gave me the most power on the dyno. Also have brian crower stainless nitraye coated flat dish valves. And bc valve springs and retainers. Supertech bronze valve guides. Fererra valve seals. Cometic gasket. Acl bearings. Arp everything. Lol aem fpr. Aem fuel rail. Rc 310cc. I know id have to uprgrade my injectors and fuel pump for boost. Skunk2 pro series im. Skunk2 70mm alpha series tb.

dantamparacer

Would you happen to be at a "high" altitude such as Colorado? This could cause the numbers to be a little low due to the lower air pressure to begin with.

mar778c

iTrader: (1)

As long as the numbers are within 5% of each other, I would not worry. The absolute numbers are very dependent on the tool and as others have mentioned the engine configuration.