Cams..Learn me about them

[jmzneal]

94 2.3 xlt Ranger is getting refreshening...I'm port matching the manifold, redoing the fuel rail and insulating it, opening up the TB some, Gutted the MAF. And am planning on putting a new cam in it if i can learn what's what on one.....So can ya'll explain cams i know nothing about them...how to change them anything...I'm learning as I go on this engine.

 

[jmzneal]

I put the Modded MAF on yesterday and it made it sound better/meaner and i see a little mid and upper improvment so that makes me want to finish the rest of the Porting and Matching and exhaust....and all i really want to know about the cam is what "size" or whatever i should get for a small mid range improvement so i don't lose in town dirveability.

 

[Ozwynn]

you don't need a new cam, just advance your cam timing about 9*. any speed shop or performance shop sells a timing set that has an off set for 9* advance (if not there will be somebody that knows how to advance the cam timing 9* using the timing set on your engine, I have only done this on Over Head Valve engines and once on a DOHC Toyota. it was tricky on the Toyota with out the timing set and took about 8 hours to set it up right, for comparison, my brother's 3.0L toyota took 30 min to set up with a set already marked for 9* advance). That little engine is pretty well maxed out internally from the factory. most engines come with the cam timing retarded for emissions so you can play with the cam timing. There are other things you can do externally to get more torque (and as a result, more HP) like a turbo.

You want torque on that motor, not HP. Honda claims that the engine in the 2000s will make 700 HP, but it does it at such a high RPM that it is really unusable. it is easy to make low end torque and not spend alot of money. Unless you plan on putting your truck on a race track and spin the engine at 9000 RPMs you do not need a new cam.

If you are looking for more acceleration and throttle response then you want to make torque. A new cam will certainly do this for you, but it is not really needed.

now to answer your question.
the cam operates the valves. The cam lobes push on the rockers, the rockers open the valves. The cam (or cams) is (are) driven off the crack shaft by either a Chain, belt, or gear. Custom grinds refers to the grind on the cam lobes (how far they open they open the valves, how long they stay open).

 

[jmzneal]

Good Point..so to back up and punt again....i'm going to advance timeing instead of getting anew cam...

what about all the intake and exhaust stuff...is all that going to hurt my low end accel b/c that's really what i'm wanting to do is gain low end...like climbing hills is retarded with all the extra weight in the bed...4.10 gears w/ l/s for the rear end are coming...

What about a tuner...i don't like the idea of a preprogrammed chip since i'm redoing the intake and exhaust for more flow or is there a chip that i can by and program my self???

i'm putting flowmaster 50delta's on it this week end...there smaller cased and more restrictive than the 40's....i really think my CatConv is clogged b/c my engine has 170K on it and it's never been changed...so i'm going to get a universal one and strap it in place of it..i'm keeping the stock headers and just heat wrapping the poop out of them b/c they give off so much heat i know the intake is getting hotter b/c of it

i'm putting new coil packs on it..msd and new wires and plugs

when i port match the lower intake i'm going to replace my injectors and insulate the fuel rail at the same as cleaning my tb and porting it and the upper manifold as much as possible....should i get more flow injectors(like 16lbs) or stick with the stock 14lbs...

I know i have lots of questions but i don't realy have anyone around me that knows how to work on little engines...every body tells me to do stuff like gut the CatCov, change the cam, get the head redone, get forged pistons....but aparently all that does is increase high rpm HP which i need low end HP and torque....their all dragers with small blocks and N02 and old Novas...

thanks for explaining the cam thing...i knew the basics of what they did i just don't know what degree or lift or what ever make what kind of hp at what rmp range

 

[Dave R]

The only way a 2.3 litre motor is going to make good bottom end torque is with a supercharger. You just do not have the displacement needed to get the air in the ports moving nearly fast enough below 2000-2500rpm to get good cylinder filling.

By doing any sort of radical porting of the head your actually killing the bottom end.

Welcome to physics 101.

 

[Ozwynn]

ok lets do your questions one at a time.

I read your post in the other thread, you fucked up a perfectly good MAF..... get a new one. the mod you made will make it run rich and foul the plugs and you didn't gain anything except some growl ...... ASS Dyno is not accurate an often wrong.

you won't need a chip or a tuner. with a properly working MAF. your stock computer and injectors are quite capable. I would only use a chip on an automatic, and that is only so I could change the shift points.

port matching is fine, but, the money is better spent else where, like building a tri-y header and port matching the exhaust.

you only need higher energy coil packs when spinning at 9000 rpms. I would recommend 8mm wires (more efficient) and I personally like Bosh platinums (no particular reason, I just like them.). again, MSD is not needed unless you plan on spinning the engine beyond the capabilities of the computer.

A larger TB is a good idea but I don't know what would be a good 1, 4cyl is not really my thing.

4.10's are your best mod. you will get the most gain for the dollar buy using the 4.10's. easiest/cheapest way to do that is find an axle that already has them.

don't buy a cold air kit. all this will do is show your friends how much money you have to waste. your truck already draws cold air and the stock intake tube is sufficient to make low end grunt with the cam you already have.

The only reason I am telling you to stay with your cam is because it is already a capable cam for your engine. I don't know what the valve geometry is on your engine but maybe some 1.6:1 or 1.7:1 rockers could open it up a little bit. However, check with the ford SVO tech support hotline to find out if you already have these.

wrapping your header is a good idea. I use plate between the intake and exhaust on my toyota and it works just as well (got the idea from the heat shield used between the carb and engine on the 460 I had in my F-250), But header tape would be better for other reasons (like keeping heat away from the master cylinder and clutch master)

you would know if your cat was plugged, it smells like rotten eggs and backfires and misfires alot when the engine is under a load. the stock cat is already high flow.

your muffler choice is fine.

Remember what your goal is, those drag guys have a different goal and think the more HP the better, you want torque in a daily driver.

stay away from any mod that has you add a resistor to any sensor....... just makes you run rich and it cause problems later.


Hope this helps.

I agree with DaveR, super charger or a turbo is the best way to go. I only went into the cheap stuff.

 

[jmzneal]

run rich fowl plugs???? K i don't disagree but it seems to be running fine other than it being louder....i only increased the air flow. the sensors are untouched and should be reading everything just like always
supercharger it is then....i put on flowmasters over the week end and it really made it loud...not like a burner but like a dirt track 4banger...speaking of which, is what i'm going to rebuild the engine like....not FOR dirt but LIKE a dirt track car... I'll get it ported polished, cam'd, overbored... what ever by some one that does dirt track cars down in the Shelby, NC area and find a charger for it.......i'll get the tranny rebuilt and a 4.10 rear end w/ l/s and all that too....lots of money to spend but not lots to go round
(mind set in LIKE a dirt car is that they have to hit high speeds in short areas)

What should i expect out of it when i'm done? Will it suprise me? What am i looking to spend....I see lots of ppl w/ 2.3 turbos but does that mean supercharged....what's the diff other than cost and function(turbo on exhaust and SuperCharger on intake)

 

[Dave R]

The only reason I am telling you to stay with your cam is because it is already a capable cam for your engine. I don't know what the valve geometry is on your engine but maybe some 1.6:1 or 1.7:1 rockers could open it up a little bit. However, check with the ford SVO tech support hotline to find out if you already have these.

Unfortunately due to the design of the SOHC head these are not readily available. Esslinger was talking about making a batch but I don't know if they ever did.

 

[Wicked_Sludge]

BDAB, some good info, but i disagree on a few points:

first off, the MAF mod has not changed the actual sensor in anyway way. all it has done is remove the excess material from the body of the MAF. the sampling tube is untouched, thus the sensor is reading the same as it used to.

the stock 14lb injectors are good up to around only 150HP. if he makes 50 more ponies over stock with his mods, the computer will be at full rich and unable to add more. that said, an adjustable fuel pressure regulator is a cheap and easy way to "cheat" and get more fuel without upgrading injectors and MAFS.

MSD works very well for improving low end grunt and idle quality. at lower RPM, it fires each plug multiple times to ensure a quality flame front. its at the higher RPM range (after it switches to single fire) that it doesnt differ from the stock ignition.

 

[Bob Ayers]

first off, the MAF mod has not changed the actual sensor in anyway way. all it has done is remove the excess material from the body of the MAF. the sampling tube is untouched, thus the sensor is reading the same as it used to.

Anything you do to change the air velocity across the MAF sensor will change the air flow measurement it takes, and screw it up!!

 

[jmzneal]

???i don't know if it did or not...i put flowmasters onit and naturally it's going to get more of a rich smell just from that...as far as the MAF being messed up???? It idle fine and runs as good as always...(giving that it's been pinging since i ran it dry a while back and burnt a piston ring) as long as it runs until i get the other motor puttogether i'll be happy...

 

[Bob Ayers]

???i don't know if it did or not...i put flowmasters onit and naturally it's going to get more of a rich smell just from that...as far as the MAF being messed up???? It idle fine and runs as good as always...(giving that it's been pinging since i ran it dry a while back and burnt a piston ring) as long as it runs until i get the other motor puttogether i'll be happy...

If the MAF sensor isn't measuring air flow accurately (either dirty from using a K&N air filter, or modified) a lean condition will exist, which will cause pinging.

 

[Dave R]

Anything you do to change the air velocity across the MAF sensor will change the air flow measurement it takes, and screw it up!!

Well, yes and no. It will indeed screw it up BUT, if any modification is done accurately and with fore thought, the MAF sensor can be improved. Yes, you are allowing more total air flow into the intake tract per volt output on the sensor but, if this modification is accompanied with a porportional increase in the injector's capacity to inject fuel, things balance out and you get a better breathing MAF. The two rates (MAF flow vs. signal output and the injection rate) can be off by a bit as the computer will adapt some but, they have to be kept close.

 

[Bob Ayers]

Well, yes and no. It will indeed screw it up BUT, if any modification is done accurately and with fore thought, the MAF sensor can be improved. Yes, you are allowing more total air flow into the intake tract per volt output on the sensor but, if this modification is accompanied with a porportional increase in the injector's capacity to inject fuel, things balance out and you get a better breathing MAF. The two rates (MAF flow vs. signal output and the injection rate) can be off by a bit as the computer will adapt some but, they have to be kept close.

Dave, I agree with your theory, but the area around the MAF isn't the limiting factor for air flow into the engine. Modifying it will not increase the total
air flow into the engine, just decrease the velocity of the air flow.

 

[Dave R]

Dave, I agree with your theory,

It's a proven theory at least. Several guys here have done it, all with good success. I've been planning on doing a bit of empirical research on this modification but, as usual, there is not much spare time to throw at it.

but the area around the MAF isn't the limiting factor for air flow into the engine.

Never said it was. But, this is just one of numerous modifications that should be undertaken before spending "real" money on the engine. And definitely beats spending money on an aftermarket MAF sensor that does the same thing.

Modifying it will not increase the total air flow into the engine, just decrease the velocity of the air flow.

Yes, it will decrease the velocity at the MAF with all things being equal. But that's the point, decreasing the velocity at all points in the system, at any given rpm, will allow the system to flow better, thereby allowing better cylinder filling overall. Unless you've gone too far overboard, of course.