101 reasons you should dyno your stock car.

[hattech-v]

oh... when u mention about compression... now i'm going to check my compression... whats the figure suppose to get for 16b?

 

[shiroitenshi]

Static compression ratio.. if you can tell me the piston dome volume (dome volume - valve reliefs = dome volume cc) .. I can tell you...
assuming the c-speed's combustion chamber volume is right, and you aren't using the flatface valves for higher comp or skimmed the head before..

If the compression like you did one last time.. supposed to be around 215-220 or so, I think.. although sometimes can find 190s.. B16A's supposed to be 150+, so maybe my engine is just 'healthier'.. Anyway.. one thing I understood from these numbers is that they reflect how much pressure they can seal.. in a way, how well the seals are sealing.. they can't tell you your static compression ratio.. nothing!! If your piston rings are whacked, they will show lower pressure seal numbers.

Not very helpful in terms of diagnosing the engine's health.. So I'm still thinking about doing leakdown testing.. but not sure when can try yet.

Leakdown test is supposed to be able to show exactly where the compression losses happen in the stroke.. but until I understand 100% of how it works.. not going to happen anytime soon..

Just met Siong VTEC and learnt a couple of things from him about building engines.. cool stuff.. :P
Damn friendly guy. (^_^)

 

[V8_nutter]

yes.. why? You think I'm running rich on the lower end? If you think so, you might be right.. After the install of the FPR, no 15.x AFR.. all lower 14s. However, the ECU may have corrected that after that.. I won't know until I do an AFR check for a second time.

Final AFR is a meager 13.2.. if you just want to know my final AFR... plugs are showing correct mixture, so I didn't bother too much about it. I didn't get a chance to do a second afr reading check, but planning to once I get another LM-1 unit.. I want to observe how much the stock ECU can adjust in closed loop mode.

Before, the plugs were showing whitish tips, showing lean.. so I plonked in an R regulator.. ghetto-style.. :P

No 12.x AFR ler... not high comp engine...

But unfortunately I didn't log it in a pc. because the unit didn't come with auxbox for RPM based AFR readings. Just took the car for a run and observed the AFR reading (obviously I'm not driving during that time.. hahaha)

Comp numbers are like I posted before.. 215's for two, except one doing 195 and 200.

But as you can see, the power starts to come at 4K+

I think my EGTs are rather high though.. because of the rapid blue-ing (took only a week.. actually holidays so I didn't drive much.. so I'd put the time at possibly 3 days of 2-3hour driving per day.) of my extractors.. again.. this all guesswork unless I drill a hole and mount an EGT sensor.

Your ignition might be low then,,,im guessing around 14.

 

[shiroitenshi]

Your ignition might be low then,,,im guessing around 14.

But it was 16 when checked on the dyno.. Why do you say that?

I think you do mean the static ignition, right?

 

[V8_nutter]

14-16 is norm reading. Shiro,,,try smoothen your chamber so you can increase ignition by at least 6-8 point more,,,it will make torque even fatter and generally reduce knocking.

After your head is knock resistence,,,then you can upped comp more without worries. So you can choose high comp piston with high ignition,,,these will flatten out the torque curves.

 

[shiroitenshi]

14-16 is norm reading. Shiro,,,try smoothen your chamber so you can increase ignition by at least 6-8 point more,,,it will make torque even fatter and generally reduce knocking.

After your head is knock resistence,,,then you can upped comp more without worries. So you can choose high comp piston with high ignition,,,these will flatten out the torque curves.

okay... but wouldn't smoothening the increase the chamber volume and slightly reduce compression?

Or do you mean just going around it with fine grit sandpaper? :P

But if you mean the area around the valves.. hmm.. that's a thought... Seen some things that made me think something up with those.

What do you think of these? compromise reliability or not? Thinking about doing them... In theory, should seem like they'd reduce the air friction travelling down to the valves.

This one mat salleh idea... shaved valve guides.. if thinking about it.. sounds like a feasible idea... now if only I can get a head with cracked valveguides on the cheap. hahaha.

 

[V8_nutter]

okay... but wouldn't smoothening the increase the chamber volume and slightly reduce compression?

Or do you mean just going around it with fine grit sandpaper? :P

But if you mean the area around the valves.. hmm.. that's a thought... Seen some things that made me think something up with those.

What do you think of these? compromise reliability or not? Thinking about doing them... In theory, should seem like they'd reduce the air friction travelling down to the valves.

This one mat salleh idea... shaved valve guides.. if thinking about it.. sounds like a feasible idea... now if only I can get a head with cracked valveguides on the cheap. hahaha.

I already did shaving the valve guide long time ago,,,machine shop here can do this. Im talking about smoothering the chamber, not "korek" the chamber. From the piston you can see different type of brownish burnt,,,from there is the point of detonation (if you can read it). The chamber side that prone on knocking is the one that must be smotthen out.

These are the thing they didnt teach at engineering school:shades_smile:

Some of the engineering shop here can do things that overseas can do. You can angle the valve seal, backcutting and shaving the valve stick, Opening and deeping the chamber,,pumping the valve guide deeper for the most radical cams (so spring dont bind).

If you have a well burnt head/chamber,,,once you open the piston youll be suprise that there will be no deposits,,,not charcoal or whitish colur. The head itself will clean the chamber ,,.

 

[V8_nutter]

Those are the black art that i learnt from my gurus,,,to be frank most 11sec machine do practice this,,,otherwise their machine wont do 11.

 

[shiroitenshi]

I already did shaving the valve guide long time ago,,,machine shop here can do this. Im talking about smoothering the chamber, not "korek" the chamber. From the piston you can see different type of brownish burnt,,,from there is the point of detonation (if you can read it). The chamber side that prone on knocking is the one that must be smotthen out.

These are the thing they didnt teach at engineering school:shades_smile:

True.. actually I did met a guy from engineering school long time ago.... 'tembak' him with a lot of questions and he gave me a blank look.. ROFL! Heck.. when I asked him how turbo's made power.. I think he started 'cold-sweat' already.. :P

AFR and what it means oso dunno.. (O_o)

I don't understand how the CC side correlates to the hot spot on the piston, to tell you the truth, but I can guess smoothening it will help flow air faster around that area, so the air density around that area decreases, reducing the likeliness of a hot spot. (I think lah.. you're the professional here.. :P)

 

[shiroitenshi]

Those are the black art that i learnt from my gurus,,,to be frank most 11sec machine do practice this,,,otherwise their machine wont do 11.

Yeah.. but some of the setups too extreme for street cars.. when I saw the head.. First thing I thought was "Extreme!"

I think 13+ compression for you guys are a walk in the park.. :P

I'm waiting to see if anyone breaks 11 sec barrier.. on NA in sepang..

Hoping to see tubed body do that and not something extreme lightened like seiki's ride I saw in Terengganu.

 

[chris2000]

I already did shaving the valve guide long time ago,,,machine shop here can do this. Im talking about smoothering the chamber, not "korek" the chamber. From the piston you can see different type of brownish burnt,,,from there is the point of detonation (if you can read it). The chamber side that prone on knocking is the one that must be smotthen out.

These are the thing they didnt teach at engineering school:shades_smile:

Some of the engineering shop here can do things that overseas can do. You can angle the valve seal, backcutting and shaving the valve stick, Opening and deeping the chamber,,pumping the valve guide deeper for the most radical cams (so spring dont bind).

If you have a well burnt head/chamber,,,once you open the piston youll be suprise that there will be no deposits,,,not charcoal or whitish colur. The head itself will clean the chamber ,,.

Hi Bro,

You know any reliable machine shop that can replace valve seat then do the 3 valve angle on the new seat and cut angle on the valve area? All this for B-Series head?

 

[shiroitenshi]

If you have a well burnt head/chamber,,,once you open the piston youll be suprise that there will be no deposits,,,not charcoal or whitish colur. The head itself will clean the chamber ,,.

Actually I've seen this.. the picture I posted here a while back is actually an engine that's seen quite some mileage.. around 15-20K kms.

It's clean allright. :P

I'm sure you've heard of this engine.. its one of the earliest crazy builds.

 

[J101]

hey shiroi,

just to update you that the latest LMA1 has an option that comes with the LMA2(personal rpm kit). rough quote from KSP few weeks back was RM2100.

im planning to get a set if the prices is falls below 2k.

the old style using LMA3 is a mess. no joke but good fun.

But unfortunately I didn't log it in a pc. because the unit didn't come with auxbox for RPM based AFR readings. Just took the car for a run and observed the AFR reading (obviously I'm not driving during that time.. hahaha)

 

[V8_nutter]

Hi Bro,

You know any reliable machine shop that can replace valve seat then do the 3 valve angle on the new seat and cut angle on the valve area? All this for B-Series head?

I never ask my mechanic where he sent the head,,,ill try asking for you then. But have to wait larr,,,be patient. Ill PM you:shades_smile:

 

[shiroitenshi]

I never ask my mechanic where he sent the head,,,ill try asking for you then. But have to wait larr,,,be patient. Ill PM you:shades_smile:

PM me oso..

 

[Johnny_9]

Some "baseline" info to consider
- What is the "leak-down" / compression test nos for the engine
- How much oil does the motor need topping up every month?
- At WOT - how much back smoke is there?

 

[shiroitenshi]

hey shiroi,

just to update you that the latest LMA1 has an option that comes with the LMA2(personal rpm kit). rough quote from KSP few weeks back was RM2100.

im planning to get a set if the prices is falls below 2k.

the old style using LMA3 is a mess. no joke but good fun.

The old style has multi channel logging..

the new style I haven't seen...

Maybe we can arrange a group buy for cheaper price.. hahaha.

 

[hattech-v]

better get the lm1 with rpm converter... easy for doing datalog n auto-correction...
if u buy directly from the net, u can get it about 1.5k... exclude the delivery n tax...

 

[hattech-v]

but lc-1 much better since it look very simple..
but 16 in 1...

 

[J101]

yeah prolly just order from the net better. hehe.

better get the lm1 with rpm converter... easy for doing datalog n auto-correction...
if u buy directly from the net, u can get it about 1.5k... exclude the delivery n tax...