Long story short, tech forum doesn't wanna talk to me. lol. So I ask here... the motor smokes on full throttle and launches and such... sometimes even 1/2 throttle... it's oil smoke for sure...

Comp check: 250-250-250-250
Leakdown: 10-10-10-18

I didn't listen to the first 3 but on the 4th cyl (leaked 18) I put my ear to the intake filter and heard air noise, so I'm assuming it's the valve seats? To my knowledge the head has never had a valvejob and I'm the 3rd owner. :-(
Brand new block built by a respectable Honda engine builder... with brand new rings on my JE pistons.

Anybody want to reinstate my hopes that all 4 cylinders have valve seat/seal issues?
I'm thinking of buying another b16 head and doing a valvejob on it with new seals and trying it... Think it'll fix it?

Ratliff

 

just get the head you have now rebuilt...its cheap....

 

Well I need the least amount of downtime possible, that's why I'm getting a different head.

Ratliff

 

bump 4 help. ;-)

Ratliff

 

ditto

 

I take it the head wasn't inspected closely before installing it on the fresh bottom end.Shame on you.Anyway,it may have one or more bad valve guides.Bad valve seals will usually cause an initial puff of smoke on start up and oil consumption.Bent valves or bad valve seating will not cause the smoke.The rings may have not seated and that may contribute to the smoke.But valve guides won't necessarily show with a compression test or leak down.Glenn

 

with 10% leak you should be able to figure out where the leak from all the other cyls are coming from. Don't assume anything, confirm it by doing the leakdown again. Oil cap = rings, intake (valves), exhaust (valves), coolant bubbling (gasket/crack).

 

hey NJIN BUILDR what's up? So let me ask you a question... Here's a theory (I will do the leakdown again tomorrow if I can get ahold of a compressor...)

Anyhoo, If the valve seats were bad, if you drove it like that for well over 2000 miles would it not cause the seals to go bad as well, because the vacuum from the combustion chambers would be seen by the valve guides/seals... like say, #4 has a bad intake valve seat... Vacuum and combustion pressure will be escaping into the intake manifold, which is one big unit, therefore all other intake valves will be getting a taste of that vacuum/pressure... Which, let's say 3 is closest, so #3's valve seals will be taking a lot of pressure/vacuum... Then those valve seals and possibly guides (although I would think unlikely) will be expanding/contracting/leaking due to them taking the stress of the escaping combustion pressures... not to mention if a valve seat in #4 and you drive it for a long time, that same valve SEAL will be shot... no?

Just a theory, tell me what you think guys.

Ratliff

 

anybody else feel free to give input...

Ratliff

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by teg92 &raquo;</TD></TR><TR><TD CLASS="quote">with 10% leak you should be able to figure out where the leak from all the other cyls are coming from. Don't assume anything, confirm it by doing the leakdown again. Oil cap = rings, intake (valves), exhaust (valves), coolant bubbling (gasket/crack).</TD></TR></TABLE>

aut0tek one of the soul purpose of the cylinder leak down test is to make sure that your pistons rings are sealing. Up to 20% leak is acceptable you'll have to see whats the spec for you particular motor to really find out. You said that cylinder #4 is 18..... Not sure of what 18 is unless it's 18psi (out of 100psi) is leaking. It looks to me that you got a good compression meaning that your valve guides and seals are fine, headgasket, no cracks (coolant bubbling).

 

Well indeed the compression check shows 250-250-250-250 however the leakdown test showed 18% (18psi out of 100) leak which seemed to be coming out of the intake side of the house... But the reason I'm asking about it is because most people say that 4% leakdown is a decent number to get out of a strong-running B-series... So mine doesn't run strong, and I now think I know why. :-(

Ratliff

 

i had this problem...it smoked everytime you gassed it...i mean just puffs of smoke were coming out...the whole bottom end was rebuilt and the head was bought used(i know i should've checked it out first)...but then the motor had about 1-2 miles on it and it smoked up a storm...compression test read 200 all the way across...didnt do a leak down...but i took the head off, took it to the shop, one of the valve guides dropped down, causing alot of oil to burn...fixed that guide, started it up, and voila, no more smoke...oh yeah, and replaced all the seals, cut all the seats(3 angle), and replaced valvesprings/retainers(rocket motorsports)...even bought a new set of cams(buddy club spec 4's) while i was spending all this money... ...and good luck with your motor...hope you fix it.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by aut0tek &raquo;</TD></TR><TR><TD CLASS="quote">Well indeed the compression check shows 250-250-250-250 however the leakdown test showed 18% (18psi out of 100) leak which seemed to be coming out of the intake side of the house... But the reason I'm asking about it is because most people say that 4% leakdown is a decent number to get out of a strong-running B-series... So mine doesn't run strong, and I now think I know why. :-(

Ratliff</TD></TR></TABLE>

4%leakdown is astonishing for a street set up maybe for a race car. 20% leak down is the maximum. If you got the time tear the motor and check the bore on cylinder #4

 

Well like has been said up to around 20% is pretty normal for a street engine.Leakdown testers very quite a lot.I recommend the Snap-on single guage unit to my customers,as it seems to give the most consistent readings.You also need to check the engine the same way every time.A cold engine will show higher leak than a warm one.My customers that check leakdown on a regular basis(2-3 race weekends when they check lash)will see leakdown going up and down a few percent every time so you need to look at a trend to be worried.I've never seen any damaged valve seals on engines with high leakdown.As a side note I've dynoed engines at the end of the season.These engines left the shop with 4-6% leakdown and returned at 25-30%.They only lost 1 or 2% of the hp/torque that they left with.They did have higher crankcase pressure because of ring tension loss and wear.
Glenn

 

TY. I guess we'll see what happens with the new head... I picked up a p&p'ed b17a head with a cracked guide for $250.00 and it's on it's way to the machine shop for new guides, valvejob, and seals. (w00t) If after a new block AND a new head, if it still smokes, screw it. It's probably cursed. LOL.

Ratliff