Porting na head

[Deathstar]

1. What cam did you buy?
->Crane #12 ordered almost everything from Howell Automotive I thought about going to a #16, but this car is an automatic. Was afraid I might run into idle problems and would have to install a stall converter. The SRTs that I have seen with those cams or bigger are really lumpy.

2. What were the lift/duration numbers versus what the stock NA PT has?
-> I forget the specs on stock but it was a defined increased in durration

3. I see (in your photos) that the PT pistons are Tir-angle topped with valve releifs. How did you know how much head to deck off without crashing the pistons into open valves?
-> The stock pistons from my understanding still allow for free passage in case of timing belt failure. Knowing this, I had all the room in the world to shave. I did .020 but really would like to have pushed .040, except a timing belt failure now would probably allow them to hit.

4. How do you think your mileage has been affected with the new cams & porting?
-> It dropped from 21 to 17.5, and that is driving normal. No peddel mashing. But, I have not tuned it on the Dyno nor added the Neo yet. I assume that will bring it back closer to 21 again.

[THS_Cruiser03]

--------------------------------------------------------------------------------

1. What cam did you buy?
->Crane #12 ordered almost everything from Howell Automotive I thought about going to a #16, but this car is an automatic. Was afraid I might run into idle problems and would have to install a stall converter. The SRTs that I have seen with those cams or bigger are really lumpy.

>(Tom) That #12 looks like a nice cam, but the #16 would be pretty rough to drive around all day on IMO, not to mention the stall converter problem. I think you made a good choice! And Howell has the best prices I've seen, $100-150 lower than anybody else.

2. What were the lift/duration numbers versus what the stock NA PT has?
-> I forget the specs on stock but it was a defined increased in durration

>(Tom) Thanks to your info I found the cam specs. at Crane, here they are compared to stock:

Crane PT #12 cam -
Part Number: 193-0012
Grind Number CHR-246-12
Advertised Duration Intake/Exhaust 246 / 246
Duration @ .050 Intake/Exhaust 204/204
Lobe Separation 112
Gross Lift 364/364

Stock Cam -
Part Number: Stock Cam Specs BACK TO LIST
Advertised Duration Intake/Exhaust 248/248
Duration @ .050 Intake/Exhaust 194/196
Lobe Separation 113
Gross Lift 325/259

- So to me the real power comes from the GREATLY increased lift. I'm guessing the longer the duration the "Lumpier" your idle quality. The lumpier cams don't breathe as efficiently until they get to 2 or 3k RPM's. For a street car with street racing intentions this is probably just right! For my car I might actually go with the #10, since I'm not likely to race very often.


3. I see (in your photos) that the PT pistons are Tir-angle topped with valve releifs. How did you know how much head to deck off without crashing the pistons into open valves?
-> The stock pistons from my understanding still allow for free passage in case of timing belt failure. Knowing this, I had all the room in the world to shave. I did .020 but really would like to have pushed .040, except a timing belt failure now would probably allow them to hit.

>(Tom) Probably best to have played it safe. You didn't even need to deck the head, but raising your comp. ratio should be good for at least 12-15 HP, cams & porting are just icing on the cake. I wouldn't be surprised if you're driving a 170+ HP NA PT right now.

I like what you said about the increased throttle response, which cannot be played down. When you floor it against a PT GT you'll be 1-1.5 seconds ahead of their turbo lag, which might be good for a car length! I'm guessing your torque curve has increased significantly as well, which should help you off the line.

4. How do you think your mileage has been affected with the new cams & porting?
-> It dropped from 21 to 17.5, and that is driving normal. No peddel mashing. But, I have not tuned it on the Dyno nor added the Neo yet. I assume that will bring it back closer to 21 again.

>(Tom) So according to your numbers you dropped about 16%. I'm guessing you probably did some pedal mashing *winks*. C'mon! How can you possibly have just modded your car and NOT have let loose a few times...? *laughs* I'm not sure what type of tuning you're talking about? What else can be done with the equipment you have?

Also, any chance you can record a digital file of what your engine idle and revving sounds like? I'm sure myself and others are curious. Is it possible to post sound (MP3 or WAV) files here? If not you can email it to me.

FYI My MP3 player has a nice built in sound recorder on it (perhaps yours does too).

Thanks so much for your replies to this thread! You're leading the way to making NA PT's something to watch for on the street. I can't wait to see what your numbers look like.

Tom

[Deathstar]

>(Tom) So according to your numbers you dropped about 16%. I'm guessing you probably did some pedal mashing *winks*. C'mon! How can you possibly have just modded your car and NOT have let loose a few times...? *laughs* I'm not sure what type of tuning you're talking about? What else can be done with the equipment you have?

Also, any chance you can record a digital file of what your engine idle and revving sounds like? I'm sure myself and others are curious. Is it possible to post sound (MP3 or WAV) files here? If not you can email it to me.

I have adjustable cam gears on the car. They are currently set at Zero, but with the shaved head they are probably retarded at least 1 degree. Shaving the head shortened the drive side of the belt. Most common advice I have seen is to advance the intake by 2 degrees and retard the exhaust by 3. I figure it is going to cost me about $300 in dyno time to tune them. The Neo shuold also lean out the motor giving it more HP and better gas mileage. Well, the better gas mileage is while there is no peddel mashing. :-)

You are correct, it is much more dificult driving the car without doing the geforce thing from a stop light. I will video the dyno and record how the car sounds. I am amazed at how deep it sounds, no Honda whinning or bees in a can, the 2.5" glass packs and lake pipes gives it a really deep, solid sound. sitting at idle, every asks "That is no PT motor, what kind of engine did you put into it?"

[Deathstar]

Originally Posted by lakersfan1

Did you get it to a dyno yet? I'm looking to order cams in the next couple days so I can make sure I have them for installing over July 4 holiday. Without seeing dyno numbers, I'm going to have to order 10's on Stockum's advice. If I see decent numbers with the 12's without NOS, I'd rather get 12's since if I go turbo later, they're more versatile in that application ..... hence their resale is better. It seems NOONE does dynos on thier NA Cruisers. I can't find anything on the net for NA Cruiser dyno results. A full graph with AFR would be awesome.

I am trying to get the TB ported by Howell then get to the Dyno. If you can wait, let me get some real numbers from the dyno and see what degree settings work best. Hopefully this will get you going in a solid direction. I'm still experimenting, let me finish the mad scientist stuff.

I set a budget of $6,000 to do both the motor and body work. I was able to get some super deals on a Pteazer hood for $250 and my neighbor owns a small body shop so I have been able to streatch that budget a long ways to get most everything you can for a NA PT.

I would love to see some more strong NA PT's out there and I hope my tests can help.

[cleverklutz]

Have you ever thought of doing a functional ram air setup? That would help pick up some HP on the top end. If you were to make the airbox fully airtight with a good hood, or put on a hoodscoop and plumb in air lines you should be able to shove a lot of air in at speed. If the n/a engine is indeed faster off the line, then ram air could help hold a turbo off for that much longer.

The only thing I'm not sure about is I think the PT uses a MAP sensor and I don't know if it will see all the air flow or not since it just senses barometric pressure. I know MAF sensors work better with ram air.

Ben

[THS_Cruiser03]

Originally Posted by Deathstar

I have adjustable cam gears on the car. They are currently set at Zero, but with the shaved head they are probably retarded at least 1 degree. Shaving the head shortened the drive side of the belt. Most common advice I have seen is to advance the intake by 2 degrees and retard the exhaust by 3. I figure it is going to cost me about $300 in dyno time to tune them. The Neo shuold also lean out the motor giving it more HP and better gas mileage. Well, the better gas mileage is while there is no peddel mashing. :-)

You are correct, it is much more dificult driving the car without doing the geforce thing from a stop light. I will video the dyno and record how the car sounds. I am amazed at how deep it sounds, no Honda whinning or bees in a can, the 2.5" glass packs and lake pipes gives it a really deep, solid sound. sitting at idle, every asks "That is no PT motor, what kind of engine did you put into it?"

>(Tom) I bet she sounds awesome! I'm really looking forward to hearing her, glad the lake pipes and g-packs are working for ya'. They LOOK like the sound great in the photos FWIW. *laughs*

Based on your project (which has me REALLY excited for my NA PT) I'm planning on mimicing your actions to some degree. I'm looking to do the following:

• get my head ported and decked .020~.030 (don't want to go higher than 93 octain for daily driver)

• Go with the #10 crane cams (don't plan to race often just want more power than stock without too much mileage penalty).

• I'll add the KN cold air intake and dynomax muffler later this year.

• Depending on how the car performs (power vs. MPG loss) I may also go with a stage 1 jet chip for the NA 2.4L - I'll have to feel it out a bit though (really want to stay at or above 23 MPG - getting about 28 now)

I'm curious about something however:
I don't have adjustable cam gears (only the stock ones). So I'm not understanding why you said you needed to tune in the cam advance/retard based on the decking of the head retarding them? If the cams are timed together and set a 0 degrees then when you put the belt on, they're still set at 0 degrees....right? What am I missing here?

Do you think I'll need to do this as well with the slightly milder #10 cam? (see specs. vs. stock below) The #10 has much higher lift than stock, but the duration is only 6 degrees longer. I'm thinking I might be able to live with the stock cam gears based on that?

Crane #10 Cam-
Part Number: 193-0010
Grind Number CHR-242-10
Advertised Duration Intake/Exhaust 242 / 242
Duration @ .050 Intake/Exhaust 200/200
Lobe Separation 110
Gross Lift 354/354

Stock Cam -
Part Number: Stock Cam Specs BACK TO LIST
Advertised Duration Intake/Exhaust 248/248
Duration @ .050 Intake/Exhaust 194/196
Lobe Separation 113
Gross Lift 325/259

I understand the concept when you said this:
"Most common advice I have seen is to advance the intake by 2 degrees and retard the exhaust by 3" - to obtain maximum HP and efficiency (MPG). Is that advice SPECIFIC to the #12 cam?

Which I'm guessing you have some experience or know people who have modified 2.4L NA's with these cams before, right? Where did you find the info, or did you crunch some numbers yourself?

You rock man! This project is and will be fun! Thanks for your replies....

Tom

[cleverklutz]

On an OHC engine the cam sits on the top of the head. If you shave the head you lower the cam in relation to the head. This means your chain/belt is now too long. This can make it so that if you line the cam up on one cog vs another it is either too far advanced or retarded.

I think that's it anyways.

Ben

[THS_Cruiser03]

[quote=Deathstar;231259]Ported and shaved Heads + Crane 12's are installed on the car now. We shaved them .020, bringing the compression up a full point we think. I believe I can feel the difference in the seat of my pants, but want to get it to the dyno first. The new lake pipes are LOUD! I am dumping the header into a Thrush glasspack then splitting it out the sides in front of each rear tire. For a NA, it is starting to get pretty mean. More pics of the car to come soon.
QUOTE]

As I stated before your project has become the spring board for my own. So with that (since you've been so helpful already) I have a few specific questions/concerns about my own project NA PT. -

I'm looking to do the following to have some more fun with my PT(hopefully adding about 20+ HP and at 20+ ft lbs of torque in the process):

• get my head ported (about 1/16” removed to match intake runners) and decked .010~.020” to raise compression ratio from 9.5 to 10~10.5 (don't want to go higher than 93 octane for daily driver)

• Install #10 crane cams for increased horsepower, torque and throttle response(don't plan to race often just want more power than stock without too much mileage penalty).

Crane #10 Cam-
Part Number: 193-0010
Grind Number CHR-242-10
Advertised Duration Intake/Exhaust 242 / 242
Duration @ .050 Intake/Exhaust 200/200
Lobe Separation 110
Gross Lift 354/354

Stock Cam -
Part Number: Stock Cam Specs BACK TO LIST
Advertised Duration Intake/Exhaust 248/248
Duration @ .050 Intake/Exhaust 194/196
Lobe Separation 113
Gross Lift 325/259

Will my stock CAM gears work with this cam? (I’m hoping so since the duration is only 6 degrees longer than stock) I shouldn’t need adjustable cam gears right?

Crane clams “good idle quality” with this cam, but is that “good” for a cammed up motor or good compared to stock? Any experience with this?

Will this cam raise my redline or is that determined by the computer?

Will the stock rings hold up against the increased compression? Or should I expect increased oil consumption?

Will my PT computer and injectors be able to maintain the proper A/F ratio? (the cams not that wild so I’m hoping so, since you're already running a #12 crane cam with stock PT injectors/computer)

Will the engine require some level of “tuning” to run well, or will the computer be able to make the adjustments on it’s own?


Thanks guys I’d love to hear your feedback/opinions!


Tom

[Deathstar]

Will my stock CAM gears work with this cam? (I’m hoping so since the duration is only 6 degrees longer than stock) I shouldn’t need adjustable cam gears right?

Crane clams “good idle quality” with this cam, but is that “good” for a cammed up motor or good compared to stock? Any experience with this?

Will this cam raise my redline or is that determined by the computer?

Will the stock rings hold up against the increased compression? Or should I expect increased oil consumption?

Will my PT computer and injectors be able to maintain the proper A/F ratio? (the cams not that wild so I’m hoping so, since you're already running a #12 crane cam with stock PT injectors/computer)

Will the engine require some level of “tuning” to run well, or will the computer be able to make the adjustments on it’s own?

My #12 idles good, just a enough lump to make it sound different, but does not hesitate any when reving up from idle.

The stock gears will work with the cams, you just will not be able to fine tune them. I have not got onto the dyno yet, but I am guessing the -3 exh, +2 intake will make them perfect. But even at zero, they are surpassing stock performace in a big way.

The cams will raise your redline power, but not the redline cut. The computer will kill the engine before it reaches maximum power now, which is around 7,200 RPM.

Your stock internals, computer, injectors are fine. The injectors are good for some pretty good HP and the computer is pretty smart. Only thing is that it will always try to run rich to be safe. A AFC computer will allow you to lean it out for a little more power.

I am getting a lot of my tunning info from the SRT guys who are building lots of power in their cars. We have the same motor as them but there are a lot more of them racing than we are.

Many of the SRT guys have tried to convice me to go Turbo, but I felt that my project car is more "old school" in styling. I wanted to keep the motor NA, loud and quick to rev on the power. That is a great combination for street performance. Not many places other than the track, to kick it for more than 15 seconds anyway. Stop light to stop light in my town is much shorter than that. But the shock on the guy's face next to me who has a turbo is great. He does make more top-end power than I do, but never gets to use it. I launch, make lots of noise and already slow down for the next street before he gets to make any power. :-)

Now on the highway, it is a different story, I can kick it, quickly move ahead by a good car because of the quick power, but about 3 seconds later a well built 50trim turbo car will blow by me like I was nothing.

[Mean Green]

Originally Posted by Deathstar

Will my stock CAM gears work with this cam? (I’m hoping so since the duration is only 6 degrees longer than stock) I shouldn’t need adjustable cam gears right?

Crane clams “good idle quality” with this cam, but is that “good” for a cammed up motor or good compared to stock? Any experience with this?

Will this cam raise my redline or is that determined by the computer?

Will the stock rings hold up against the increased compression? Or should I expect increased oil consumption?

Will my PT computer and injectors be able to maintain the proper A/F ratio? (the cams not that wild so I’m hoping so, since you're already running a #12 crane cam with stock PT injectors/computer)

Will the engine require some level of “tuning” to run well, or will the computer be able to make the adjustments on it’s own?

My #12 idles good, just a enough lump to make it sound different, but does not hesitate any when reving up from idle.

The stock gears will work with the cams, you just will not be able to fine tune them. I have not got onto the dyno yet, but I am guessing the -3 exh, +2 intake will make them perfect. But even at zero, they are surpassing stock performace in a big way.

The cams will raise your redline power, but not the redline cut. The computer will kill the engine before it reaches maximum power now, which is around 7,200 RPM.

Your stock internals, computer, injectors are fine. The injectors are good for some pretty good HP and the computer is pretty smart. Only thing is that it will always try to run rich to be safe. A AFC computer will allow you to lean it out for a little more power.

I am getting a lot of my tunning info from the SRT guys who are building lots of power in their cars. We have the same motor as them but there are a lot more of them racing than we are.

Many of the SRT guys have tried to convice me to go Turbo, but I felt that my project car is more "old school" in styling. I wanted to keep the motor NA, loud and quick to rev on the power. That is a great combination for street performance. Not many places other than the track, to kick it for more than 15 seconds anyway. Stop light to stop light in my town is much shorter than that. But the shock on the guy's face next to me who has a turbo is great. He does make more top-end power than I do, but never gets to use it. I launch, make lots of noise and already slow down for the next street before he gets to make any power. :-)

Now on the highway, it is a different story, I can kick it, quickly move ahead by a good car because of the quick power, but about 3 seconds later a well built 50trim turbo car will blow by me like I was nothing.

I think you'd be surprised how fast my SRT-4 gets off of the line. Still with the stock turbo, but with the power mods I have power is almost instantaneous and the suspension is set up for the track. One of the best mods I invested in is the Aeroforce Interceptor scan gauge that comes with a shift light. Most people think you run it to almost redline and shift, but though my rev limiter is 6200 my "sweet spot" is 5500 and that's where the light is set. Used to be bouncing off of the rev limiter was easy in 1st and 2nd gear as the power comes on so darn fast, but I never miss the sweet spot now. Besides, with almost $6k into my car, it had better do what it does or my wife would kill me.
Still, your ride is going to be special. My wife has an automatic '04 na PT and while being a great car to cruise in it is slower than frozen mud. You are going to surprise a lot of people. There would be a lot of people over at PTCrew.com - Learn it or Burn it. with na PTs who are looking for some more punch. If you haven't been there, there are a lot of PT gearheads who hang out there.