732xghost

iTrader: (1)

you would probaly need more than just an exhaust for that mod to be worth it.

5-speed

right, but a big one would be exhaust. no point in flowing air in when you cant flow it out. cams, bored TB, valves/valve job... lots of fun things to make it worth it. not any time soon....

teh CL

iTrader: (1)

im sorry, i feel ur pain

5-speed

Whats the latest on ole' faithful?

teh CL

iTrader: (1)

ahh the latest..

still in pieces at school but she's gettin there..all the major body work is done, just sanding/prime/paint/clear left..

wont be done anytime soon, im not gonna rush the body work cuz i want it mint..

also, savin up for a swap..lookin to sell my f22 and h22 parts and that should help me out abit...

but ya, still FAR from done &

AgentOrange

^ true, however, with just a 230 regrind ( for the f22b1 ) and maxbore work ( 160 $ ) you'll see a great improvement with your current powerplant. Dave does AWSOME work and going to 64 mm taperd with a matched plenum and a simple regrind ( RM or web does these for our vehicles for just a little bit under 350 dollars ) you'll see gains close to 20 whp with a good tune. I gained around 17 hp 21 tq at 5384 feet !!! with a 230 regrind, along with Daves work. Im not sure what the gains are with a completely stock motor, but you can achive these with you basic I/H/E plus this work ( thats 17 and 21 ) over what i had before with your i/h/e as the baseline. Good stuff, you should look into it.

5-speed

do you have a cam gear with your 230 regrind/will i need one to move the power band below redline? i will definitely look into it. ive wanted to do something like this for a long time now.

thanks man

AgentOrange

well, here's the thing, "shifting" the powerband with the use of just a cam gear is only realy noticable in DOHC engines....at least when making power comes into play....they tend to do better off the bat. Although........With a Cam that will make power up higher, you'll need a cam gear to accomidate the extra reving/ peak power band potential which can be done by retarding the timing or advancing the timing. That is were i saw the largest performance gain.......essentialy when i went from no tune......after tune. I like the 230 lift 230 duration, but....it wasnt quite the same since the 272s are almost imposible to buy through stores these days. Oh, one more thing, the same can be said about a Cam there didnt focus on high rpm for power...lets say lowend tq, they would have to retard or advance it based of your basline run.

Here, lets study this : thanks to my man pete ....

Valve timing is usually given using two figures. The first is the number of crankshaft degrees degrees before/after TDC/BDC that the valve completely closes. This gives rise to further abbreviations of, BTDC (Before Top Dead Center), ATDC (After Top Dead Center), BBDC (Before Bottom Dead Center) and ABDC (After Bottom Dead Center).

Four stages are passed through for each four stroke cycle and these are listed below in simplified terms to explain the basic four phases involved. We will go into these phases in greater detail in the 'Advanced' section. Let's start at TDC at the end of the compression stroke.

POWER At TDC (Compression) the spark ignites the compressed mixture resulting in a burning of this mixture to create the power to drive the piston down the cyclinder. Both valves must remain closed for this power stroke.

EXHAUST At BDC the inlet valve must remain closed and the exhaust valve must be open whilst the piston in on the up stroke. This movement forces the burnt gases out past the exhaust valve to the exhaust port and the exhaust system.

INTAKE At TDC (Exhaust/Overlap) the exhaust valve must be closed and the inlet valve must be opened. The pistons downward movement causes a pressure below atmospheric in the cyclinder which allows atmospheric pressure to feed the air/fuel mixture past the inlet valve and into the engine via the inlet port.

COMPRESSION At BDC the exhaust valve must remain closed and the inlet valve must be closed. Whilst the piston is on the up stroke the air/fuel mixture is compressed dramatically ready for ignition by the spark plug. The cycles repeats with the power phase next.

If an engine was set up like this with valves opening and closing at TDC and BDC it would run at low revolutions but such basic valve timing is not good enough for an engine to develop any usable power. If you have grasped the basics and want to know more it's time to move on to what happens in a real motor.

ADVANCED CAM TIMING THEORY
I found a diagram helpful in understanding what is happening. With reference to figure 1, I have divided the two crankshaft rotations into two circles joined at TDC this should be followed as a 'Figure of Eight' through the various cycles.


Starting at TDC compression follow the left hand circle clockwise until you return to TDC exhaust. Then follow the right hand circle anti-clockwise back to TDC compression. I have divided each circle into four 90° segments giving eight phases for the purpose of our advanced discussion. The actual degree settings for cam timing will be discussed later on.

We start at TDC compression. As discussed previously both valves are closed and the air/fuel mixture has been compressed into a small area. Because the mixture takes a finite time to become completely ignited we must start the ignition before the piston gets to TDC. I won't get into ignition timing in depth here but suffice to say the faster the crankshaft rotates the further before TDC the mixture needs to be ignited. The net result of this is to ensure that the maximum push of the fully burning mixture peaks just as the piston starts its downward stroke regardless of piston speed.

POWER For the first 90°-100° ATDC both valves remain closed whilst the mixture burns causing pressure to rise pushing the piston down on its power stroke.

EXHAUST 1 At around 80° BBDC the exhaust valve starts to open. The main reason for opening the exhaust valve earlier than BDC is so that it will be fully opened by the time the piston reaches the start of the upward exhaust stroke. Most of the power from the burning mixture has been used at this point so there is virtually no loss of power by opening the valve early. Also we can use the small amount of combustion power left to begin the exhaust phase early even though the piston is still moving down.

EXHAUST 2 & 3 From BDC to TDC the exhaust valve is wide open and the rising piston is forcing the burnt gasses out of the cylinder

INLET 1 At around 60° BTDC the inlet valve starts to open. As for the early opening exhaust valve we do this to give the inlet valve a chance to be fully open by the time the piston is reaching its maximum downward velocity and it gives a head start to filling the cylinder with fresh air/fuel mixture. By the time the inlet valve is fully open the exhaust gasses are moving fast out through the exhaust port and the inertia of this column of gas causes a slight depression in the cylinder which allows atmospheric pressure to feed in the fresh mixture. Exhaust systems are designed with this in mind and the term 'Extractors' is fairly self explanatory when you understand what is happening in the engine.

INLET 2 & 3 From TDC Exhaust/Overlap to BDC the inlet valve is wide open and the piston rapidly moving down creates a depression allowing atmospheric pressure to feed fresh mixture into the cylinder.

EXHAUST 4 The exhaust valve remains open till around 60° after TDC. This is done to purge the exhaust gasses. The rapidly moving incoming mixture not only fills the cylinder but forces the last of the exhaust gasses out through the closing exhaust valve until the returning exhaust pulse stalls the flow. The swirling air/fuel mixture at this point also provides some cooling for the hot exhaust valve.

INLET 4 From BDC to around 80° ABDC the inlet valve remains open. Although the piston is now moving upwards the inertia of the incoming air/fuel mixture is stronger and results in a mini super charging effect where the mixture is initially compressed into the cylinder.

COMPRESSION After the inlet valve closes at around 100° BTDC the rising piston continues to compress the fresh air/fuel mixture in readiness for ignition and the start of a new cycle.

When you realise that this full cycle happens around 70 times per second at high revolutions you can appreciate that cam timing is a very critical factor when designing an engine. The timing figures are dependant on the camshaft(s) which are ground specifically to suit the type of engine.

As you can imagine many factors effect the factory setting of cam timing such as, the intake and exhaust systems, fuel type used, compression ratio, maximum RPM of the engine, piston and combustion chamber shapes, torque and maximum power conciderations, fuel economy, etc.

732xghost

iTrader: (1)

nice report.

ive heard people saying that a cam gear is worth it even without an aftermarker cam or regrind, for single cam honda motors. is this true.

AgentOrange

it could be depending on were you want to make up some power. I know me and my tuner both enjoyed the adjustability once this altitude switched things up.

5-speed

Thanks for all the info man. Ive got a couple more questions, because i'm very interested in getting a regrind/bored tb.
Do i need an fpr or v-afc to have it tuned correctly? if I just had it tuned with a cam gear could it be tuned properly?
Basically what im asking is- When I get my car dyno tuned (specific to the f22), what will they be tuning? my ECU?

i feel like a


also, is there a threat of detonation with a 230/230 regrind without a fpr/vafc?

which would be the best ratio between performance and reliability/daily drivability: 220/220 or 230/230?

agranado

Thanks for all your info "AgentOrange".

Hope you're well man.

5-speed

Whats the latest on you/your car anyhow?