compression pressure test

[mdsb3]

hondarian..
want to know about compression pressure reading 4 standard vtec engine:
1.b16a-

2.b16b-

3.b16a + type R piston-

4.b20b+ b16a head-

 

[shiroitenshi]

hondarian..
want to know about compression pressure reading 4 standard vtec engine:
1.b16a-
2.b20b+ b16a head-

Dependent on the piston and how well the rings are sealing.

On my B16A, it's 220 or so (forgot the units, KpA, I think.), and at with piston 1 at 160ish, I'm considered as having severe compression leak.

On other people's B20B+B16A head, it ranges from 200ish to 300, depending on compression and cam setting.

It's dependent on the amount of blowby as well, a variance of 5% between cylinders is normal.

 

[mdsb3]

ok shiro..
assume all in good condition.
accurate figure in psi.

 

[hattech-v]

u will not get the figure same as other engine... unless u did the testing on the new engine from the factory...

normally b16a around 210-220.
b16b around 220-230 (also for b16a with ek9 piston)
b20b + b16a head - 220-250 depending on what piston.

what is the most important is the figure for all 4 cylinder is almost same.
different about 25+ from any cylinder considered that cylinder not in good condition. it can be due to the worn out piston ring or leaking on the valve.

 

[shiroitenshi]

actually consider quite lasting, the honda piston rings.. because considered I never changed the rings when I converted, the mileage of my car + mileage of halfcut is already 200Kms, and I'm still getting those numbers on piston 2-4, only piston 1, and even then I'm not sure that the ring seal is totally gone case, because I can't hear any air leak through the oil cap hole, but that's because it's drowned by the sound of the LMA rattling, (hydraulic tappet? I'm not sure of the terms, seems like these two names are referring to the same thing.. it looks like a bullet, that's all I can describe it) which I'm going to change sometime in november when I'm not using the car, since it is my daily driver after all.

I suspect it's the valves not sealing properly, because I don't seem to see any black smoke from the exhaust, and i'm noting a lot of unburned fuel coming out of the exhaust (compression stroke leakage, maybe?) and LM-1 is showing very lean readings (unburned fuel is not detected by 02 sensor, for aspring tuners out there that wonders how they leaned their engine and blew them by mistake, never trust the 02 sensor totally, unless you tapped 4 into each header pipe for individual cylinder reading) (I ran open loop to test) which is rapidly corrected by the o2 sensor in closed loop a.k.a. FC goes to hell!, hence why open loop is good for observing part throttle fuelling, which is unavailable on piggyback systems, although they could cheat by supplying a constant .5v (I think that's the voltage for stoich, but better double check to make sure, if you're thinking of doing something like this) to the o2 D14 pin.)

Well, I'm going to do consider lapping the seats and cleaning the valves for better seal first (including LMA/tappet change, plus maybe new aftermarket v/s, 9.5K rpm, here I come? :P), then if it's still leaking, looks like I have to shop for some pistons and rings, crank bearings, rod bearings and a new gasket.

or maybe just a new bottom block :P
B20 is nice, but 8K is probably the safe limit for a daily driven ride, while B18C is nice for higher rpm runs, but a tad on the expensive side.

 

[hattech-v]

if u planning to buy new LMA especially the R one, better get used one. if not better get another R head..
if not mistaken R LMA cost u around 640..

get a standard b20 bottom... change the piston... secure the valvetrain... tune it properly... i think shud be no problem for 9.5k

 

[shiroitenshi]

if u planning to buy new LMA especially the R one, better get used one. if not better get another R head..
if not mistaken R LMA cost u around 640..

get a standard b20 bottom... change the piston... secure the valvetrain... tune it properly... i think shud be no problem for 9.5k

Not worrying about it, because I don't mind spending on new, because I'm not going to sell the car already, probably going to keep it as a daily driver till the doors fall off.. hahaha. That's why most of the parts I needed to fix I put new stuff, instead of used, even though they're a bit more expensive.

My recent expense on clips alone were like 100++, and those were for fender liners only.. the side skirt clips are about 16bucks each (around there, I think) and the total to that was like RM70 something (because I was not missing ALL the clips, thankfully)


As for engine.
B20B can reach 9.5K, but not for long, probably a few hard runs back to back will kill it.

One unit before this got the piston 'detached' from the rod and killed the engine and head. A few other units I've seen have cracked sleeves, severe crank bearing wear, etc. Sleeved one lasts a lot longer, but the price can give you the 'peluh sejuk' feeling.

Of course, if you maintain it like a racecar, with regular stripdowns, I think okay, but for a daily driver..hmm.. better not. I'd like to see around 150K mileage before needing a stripdown at least.

But another thing floating in my head is a turbocharged B20B stock without the B16A head, using the stock head, but probably needs to be ported for better flow.

man... that would be a great engine for a daily driver, and .5 bar boost on it's 8-9ish stock CR would be very powderful as well, for a daily driver. :P

Then I'd have to look for the GSR gearbox due to the torque though (>_<)

 

[SKYR]

Another one thing that wannna add, What about if someone running jdm b18c gsr and jun type 1 cam ??Any infos regarding the engine compression ? thanks in advance:hmmmm:

 

[shiroitenshi]

it depends on cam setting, advancing or retarding the intake cam and/or exhaust cam can give different results.