questions about my comppresion.ls/vtec

[allmotor-teg]

i have a build ls/vtec that has:
b18b1 block
b16 head milled .30 and had a resurface recently
oem ls headgasket
pr3 pistons
brian crower stage 2 n/a cams
type r valve train


also has other things but about the comppresion has me worried now, the car doesnt make power under load and and i checked my brand new spark plugs ngk iradium plugs and 2 are craked, maybe i hit the spark plug with the pistons???

[EmminoDaGreat]

Get it tuned.

[allmotor-teg]

alright i guess thats what im going to do cause i used the compression calculator and it said i have 13.58 compression and thats way way to high for a dd.

[Black4DrEK]

Get it tuned.

x2!! for the 100 time!


alright i guess thats what im going to do cause i used the compression calculator and it said i have 13.58 compression and thats way way to high for a dd.


Your setup does not have that high of compression. Ricardo, get the engine tuned.

[EmminoDaGreat]

alright i guess thats what im going to do cause i used the compression calculator and it said i have 13.58 compression and thats way way to high for a dd.

Cant be that high...

Well the comp calculator I use came to be that too, but its usually a tad on the high side.

[allmotor-teg]

but still high af dont you think??? or a better shape b16 would be better cause i was specting to be in the 11+ not 13 and bad for the car if i use 93 oct?

[nelson9995]

I did mine... same pistons... only difference pretty much is the head milll. and im at 11.9 with the same calculator with a 2 layer HG. With his HG it said im at 11 6... so the calculator cant be that much off.

[silversol]

Get it tuned, I highly doubt the pistons hit the spark plugs as high up as they are in the combustion chamber, Plus you would bend valves way before you hit the plugs

[nelson9995]

thats our next conern. we think the valves are bent. when the car is accelerated it does not respond. you have to gradually press the gas for it to start moving up the rpm. If you put it in gear car just does not go. i give it lots of gas and release clutch slowly and it is just so lazy it does not move. timing is at 0 (everything). we even did it twice. compression test was around 120-140 all across (I believe its low but I'm not sure).

[turbob20]

do compression test with throttle open. also remember when drastically milling head the head becomes closer to the block as well as the cam gears so timing can be some what sluggish even if its set at stock marks. have you tried to advance the timing at the dizzy counter clockwise to see if it picks up? if its off at the belt this might help some! ive never had this happen but milling .030 and not knowing if it has already been milled who knows just a thought. even with the throttle closed 120 is kind of low but idk. mine 240 with throttle open on all 4. play with your dizzy cause milling does affect timing in some cases i have seen and had to buy cam gears and get it back right. good luck!

[allmotor-teg]

I did mine... same pistons... only difference pretty much is the head milll. and im at 11.9 with the same calculator with a 2 layer HG. With his HG it said im at 11 6... so the calculator cant be that much off.

thats what i was saying dont thing a tad high could be from 12 to 13 compression.


Get it tuned, I highly doubt the pistons hit the spark plugs as high up as they are in the combustion chamber, Plus you would bend valves way before you hit the plugs


yea thats what i tought but im just trying to give opinions i just want to get it fixed.


thats our next conern. we think the valves are bent. when the car is accelerated it does not respond. you have to gradually press the gas for it to start moving up the rpm. If you put it in gear car just does not go. i give it lots of gas and release clutch slowly and it is just so lazy it does not move. timing is at 0 (everything). we even did it twice. compression test was around 120-140 all across (I believe its low but I'm not sure).

the car boggs at low rpm but if you hit the gas slowly it revs normal to whatever i want i have gotten the thing to 5k and its fine, maybe its gas but i have changed everything in the gas supp system.


do compression test with throttle open. also remember when drastically milling head the head becomes closer to the block as well as the cam gears so timing can be some what sluggish even if its set at stock marks. have you tried to advance the timing at the dizzy counter clockwise to see if it picks up? if its off at the belt this might help some! ive never had this happen but milling .030 and not knowing if it has already been milled who knows just a thought. even with the throttle closed 120 is kind of low but idk. mine 240 with throttle open on all 4. play with your dizzy cause milling does affect timing in some cases i have seen and had to buy cam gears and get it back right. good luck!

when i did the close throttle close it read 90 but thats when the timming was 1 off and i did open and it read 120-145 and did a wet one and went up max 15 not like a big jump,it had been milled .30 and now i did a resurface so thats why i say its milled .37 and i have golden eagle adj cam gears.

[Tech5]

was the plugs cracked in the porcelain ??? If so that is over tightening the plug

[allmotor-teg]

yea thats what i was thinking cause i could not get those things out lol. they have kinda like a not too dark color but not white either.

[Theycall_Metue]

you'll diff know if you bent a valve. d series are the only one i've in counter that you can barely tell if you bent a valve.
when i bent a valve in my jdm d15b. i though i was 1 teeth off timing, car still pull strong.
when my buddy unplug a 1 spark plug wire in his ls, it barely run, let alone drive.
it'll puff like a bitch. when a cylinder is down

[allmotor-teg]

like it does not smoke at all, no oil smell no gas smell just smells like straight pipe, i think im just going to pull the head off and see if i see vent valves cause i need my ls/vtec running right lol, it waesnt cheaply build either.

[turbob20]

not necessarily we've had several ls v's and didnt know the valves was bent till the boost went on and then a leak down test done! check the outside white porcelain part on the outside of your plugs where the part number is for cracks. will cause your problems and this i suspect if they were that tight. also always use a socket for the plugs with some kind of rubber insulator to keep from breaking this.

[turbob20]

if you dont have a leak down tester do this! if your compression tester has the part where it breaks apart like an air hose fitting on it take the valve stem thing out the spark plug end plug your air hose on it and set you compressor at about 100 psi and make sure you piston on that cylinder is tdc and all valves closed and in gear or piston will want to move down bore. turn on the air and listen at the throttle body with intake pipe off throttle open then exhaust pipe at muffler end for air then youll know and make sure it completely quiet around you to hear it. let us know.

[turbob20]

you'll diff know if you bent a valve. d series are the only one i've in counter that you can barely tell if you bent a valve.
when i bent a valve in my jdm d15b. i though i was 1 teeth off timing, car still pull strong.
when my buddy unplug a 1 spark plug wire in his ls, it barely run, let alone drive.
it'll puff like a bitch. when a cylinder is down

not necessarily we've had several ls v's and didnt know the valves was bent till the boost went on and then a leak down test done! and ran really well too it just barely had a slight skip at idle and it was 2 exhaust valves so that would explain it not smoking was just losing slight compression out the exhaust side as the bends were slight not too drastic though. depends on the nature of the bens ive seen some barely bent to snaping off and busting the piston and ruining the head. so with the compression being that big a difference on the one cylinder i would not rule out bent exhaust valves.

[allmotor-teg]

not necessarily we've had several ls v's and didnt know the valves was bent till the boost went on and then a leak down test done! check the outside white porcelain part on the outside of your plugs where the part number is for cracks. will cause your problems and this i suspect if they were that tight. also always use a socket for the plugs with some kind of rubber insulator to keep from breaking this.

sure will do thanks.


if you dont have a leak down tester do this! if your compression tester has the part where it breaks apart like an air hose fitting on it take the valve stem thing out the spark plug end plug your air hose on it and set you compressor at about 100 psi and make sure you piston on that cylinder is tdc and all valves closed and in gear or piston will want to move down bore. turn on the air and listen at the throttle body with intake pipe off throttle open then exhaust pipe at muffler end for air then youll know and make sure it completely quiet around you to hear it. let us know.

question if i pull the head and use liquid when all the valves are closed to see if it leaking????


not necessarily we've had several ls v's and didnt know the valves was bent till the boost went on and then a leak down test done! and ran really well too it just barely had a slight skip at idle and it was 2 exhaust valves so that would explain it not smoking was just losing slight compression out the exhaust side as the bends were slight not too drastic though. depends on the nature of the bens ive seen some barely bent to snaping off and busting the piston and ruining the head. so with the compression being that big a difference on the one cylinder i would not rule out bent exhaust valves.

dont you think everything will be too close and i should be better off just getting a bare b16 and use all my internals from this one but if the valves are bent i just but new ones???

[turbob20]

if you do the air test you already basically know what cylinder is low listen to see which it is intake or exhaust then you can buy the valves yourself get a simple valve tool on ebay that bolts to b series heads i can get you an item number when your ready and change em your self ill walk you through it. also yes if there bad enough you can pull the head and set it without cams of course where all valves are closed and pour water into the intake ports and look to see if water is leaking from any valves should be none at all or at most very very little. then do the exhaust side which i think it is and when you get to the culprit ones it will just run out in a small stream! simple enough right?

[turbob20]

also check you electrodes to see if any are bent together from slight contact with piston and any time you put plugs in as they get dropped all the time at the factory and stores! you should be running ngk bkr7e plugs i think with that compression as the electrode is recessed further down in a colder plug! just trying to rule out the inexpensive stuff first you know?

[allmotor-teg]

if you do the air test you already basically know what cylinder is low listen to see which it is intake or exhaust then you can buy the valves yourself get a simple valve tool on ebay that bolts to b series heads i can get you an item number when your ready and change em your self ill walk you through it. also yes if there bad enough you can pull the head and set it without cams of course where all valves are closed and pour water into the intake ports and look to see if water is leaking from any valves should be none at all or at most very very little. then do the exhaust side which i think it is and when you get to the culprit ones it will just run out in a small stream! simple enough right?

well the exhausht is not leaking i used gas was there for a couple of minutes havent done the intake cause i had other things to do but i got the block and used gas in all cylenders and 234 lost almost all gas but i let it sit for like 9 hours but piston 1 looked the same when i did the comp test couple of days it did not show me 230+ compression it was very low like the other ones looked at the pistons and didnt see any kind of wear so. question have you ever heard of 2 headgaskets with cooper spray????



also check you electrodes to see if any are bent together from slight contact with piston and any time you put plugs in as they get dropped all the time at the factory and stores! you should be running ngk bkr7e plugs i think with that compression as the electrode is recessed further down in a colder plug! just trying to rule out the inexpensive stuff first you know?

so get those spark plugs and see??

[allmotor-teg]

i found some head gaskets that are 0.5mm 1mm 2mm and 3mm for the b series, should i use one of those intead of getting another head cause i rather get the head gasket lol, i want to have high compression but i dont want to have to run e85 or somenthing or mess with the timming i want a car that i can use 93 oct and call it a day.

[turbob20]

try the head gasket thing or swap for a head that hasnt been decked! but i dont know if the head gasket will solve the low compression problem or not if the cylinder brace isnt fully seated and below the deck or at least flush. with the head being decked that much your compression should be well in the 200+ range imho.plugs are inexpensive get some bkr7e's and tighten them but dont go crazy with it tighten till you feel the collar on the plug collapse and when snug about 1/4 no more than1/2 turn. but with our compression the bkr7e's are whats recommended i think theres even a different plug for 12:5:1 and up. google it for your compression to keep cylinder temps down some.

[turbob20]

never mind that cylinder brace comment got confused with another post. lol.

[allmotor-teg]

try the head gasket thing or swap for a head that hasnt been decked! but i dont know if the head gasket will solve the low compression problem or not if the cylinder brace isnt fully seated and below the deck or at least flush. with the head being decked that much your compression should be well in the 200+ range imho.plugs are inexpensive get some bkr7e's and tighten them but dont go crazy with it tighten till you feel the collar on the plug collapse and when snug about 1/4 no more than1/2 turn. but with our compression the bkr7e's are whats recommended i think theres even a different plug for 12:5:1 and up. google it for your compression to keep cylinder temps down some.

do you have a bare b16 head that hasent been decked or nothing and about the low compression idk what it could be cause im not getting gas in the oil supply and its fine just that low end bug guessing its a sensor or somenthing cause i dont see anything wrong with it no valves that are bent to the extend that it will hit the piston i really think is a sensor cause everything else looks normal but this thing is driving me crazy, how thick the headgasket you think?? and maybe my pistons havent seat 100% yet if you fill the top of the piston and walls with gas and gas goes down very slowly is that bad??


never mind that cylinder brace comment got confused with another post. lol.

yea i was like what is he talking about.

[turbob20]

if you have a low end bog with surge could your iacv on back of the intake and the little black purge valve solenoid for the evap canister be mixed up they will intercange? or the the throttle position and map these plugs will interchange too! just tying to help im about stumped. the compression is a big deal but would still run ok just not as good as it should but not really bog much from my expieriance would be more of a miss at and off idle i would think!

[allmotor-teg]

if you have a low end bog with surge could your iacv on back of the intake and the little black purge valve solenoid for the evap canister be mixed up they will intercange? or the the throttle position and map these plugs will interchange too! just tying to help im about stumped. the compression is a big deal but would still run ok just not as good as it should but not really bog much from my expieriance would be more of a miss at and off idle i would think!

maybe is the iacv cause im using the ls one in the type r manifold and it only uses 1 bolt cause the second one doesnt match and no i had to buy a lil house to put in the back of the intake and the canister, you are like the 8 person that says that i might have them mixed up but there is no way they are mixed up cause i tried and one is way way too short and i really dont know why the low compression maybe cause the rings havent set just right cause i looked at the walls and i dont see them scrathched(idk how to spell it lol) up and down they still look like how they were after the machine shop and will the low comp make have very low hp and it would smoke before and in vtec???

[RBS]

i didnt read through the ENTIRE thread, too lazy.. but let the car idle to regular operating temp, then do another compressiont test.


when the engine was assembled, were the cams degree'd in? milled head AND aftermarket cams require this job to be done, otherwise your just half assing it... and do not stick 2 headgaskets together with copper spray; thats just dumb.

[allmotor-teg]

i didnt read through the ENTIRE thread, too lazy.. but let the car idle to regular operating temp, then do another compressiont test.


when the engine was assembled, were the cams degree'd in? milled head AND aftermarket cams require this job to be done, otherwise your just half assing it... and do not stick 2 headgaskets together with copper spray; thats just dumb.

last time i did the test i let it get to regular temp and then did it.
dont think so, what you mean by half assing it???
and i found think headgaskets so im not using 2 head gaskets, and since the comp is too high im using the thicker hg.