28 replies to this topic

[sspcivic31]

Funny thing is this is the exact same specs as the Web Cam Inc canshaft.

Web did the regrinds for jackson racing. to compare specs you need to know where the measurements for the cam are taken. ie are they all from .050" lift or are they at some other point.

[cbstdscott]

The comments about an Air/Fuel meter, a fuel pressure guage and a fuel pressure regulator are all Right On!!!

These three items are essential to tuning a fuel injected CRX. The interesting thing (to me) is that only a small amount of extra fuel pressure is neccesary for most mods you make. I am amused to see guys buying huge fuel pumps, fuel rails, injectors, etc. to "add power" when then usually end up dorwning their engines in unused fuel.

As for the Cam specs, I have found that Honda engineers (and Mugen was a thinly disguised branch of Honda) knew the most about tuning their engines. I am willing to bet that Mugen's lift and duration numbers will give good performance with reasonable streetability.

Scott

[Airjockie]

my set up, I had to lower the fuel pressure...down to 21.5 psi...any more, or less and no hp. P&P head, CAI, DC Sports header, Teg injectors, 2.25 exhaust. on a 86 Si ECU...

but that was before turbo....

[cbstdscott]

my set up, I had to lower the fuel pressure...down to 21.5 psi...any more, or less and no hp.  P&P head, CAI, DC Sports header, Teg injectors, 2.25 exhaust.  on a 86 Si ECU...

but that was before turbo....

You had to lower fuel pressure because you substituted 195cc CRX injectors for 245cc Integra injectors.

Scott

[balladeSports]

I wonder if Web cam would make me a spacific cam to my instructions. the Mugen cam also had diffrent duration #'s for both intake and exhaust, seems like they did more study into the design. Lift .386 Duration 260 intake and 280 exhaust. I'm assuning the #'s I have are from fully closed on the seat. What does from .050" lift mean?
BTW Thanks for all your help in this matter.
Cheers

[balladeSports]

Maybe the diffrent Duration #'s have to do with over lap?

[sspcivic31]

Elgin cams go here and read what they have to say.

Maybe the diffrent Duration #'s have to do with over lap?

probably because you only have the one exhaust valve to empty the chamber.

What does from .050" lift mean?

the cam is measured from .050" lift to .050" from close. most race cams use this method of measure. measurement from full close to full open look bigger so some companies use thta to pump up the numbers.

[balladeSports]

Very Intresting. That makes alot of sence Thanks sspcivic31

[Doodson]

A guy I race with took 2 cams to Colt Cams (Lightspeed , old Mugen one) and the specs that the companies said they were , were not what Colt cams measured.

My point is that some companies measure there cams just a little different , so if in fact you want a cam to do a certain thing then just call the cam company and tell them what you got in the engine and what you want in to rev like.

They make cams for a living

Doodson

[87sivtec]

.050" is also the measurement of lift that the air is actually starting to flow through the valve opening. Make sure you compare apples to apples in these cases. Advertising big numbers goes a long way towards sales. For a street cam, i wouldn't go much more than a 260-270 degree duration or it wont idle as well and you will need more compression to make use of the longer duration.

[balladeSports]

Well I guess I'll be making a few calls monday and find out what these people can do for me.
Again thanks for the help.
Even though I don't write much, I do visit alot and find the help and information great.
Happy new year.

[gtpilot]

For street motors with fairly restrictive intakes, you can run more lift and more duration but try to stay away from a lot of overlap. Overlap makes the motor slugginsh in the bottom end and doesn't start working well until you get into the mid-range. Since the Si intake is pretty restricted, a camshaft with a lot of overlap will be choked in the top end - just where the camshaft wants to do its best work. Try to find out what the lift/durations and lobe centers for the camshaft are before you buy it. You can take a top end camshaft and move the lobe centers to create a camshaft that works much better inthe lower RPM ranges.

A racing camshaft for the PE3 or PE7 head will typically have a little longer duration (and more overlap) than the intake to account for the single exhaust valve...

Kirk

[mordantly]

www.webcam.com has a good selection of cams for the D15A3 engine. You say that you want a good street cam, so the mildest or the next up cam would work for you.

If you want an instant performance improvement, ditch the Integra ECU and go back to your stock ECU. The Integra ECU makes you engine run much too rich.

Scott

im sorry i can't say this is a problem. stock si injectors/fuel pressure, '87 teg puter and she passes smog with readouts so low, most new cars don't run that clean. my si puter was fried so once the tach saw 1500+ you're eyes could see the raw gas spewing a few feet out the tail pipe so she needed a new cat to pass everytime.. luckily only a few years it ran like this so i won't have too jacked up of a block till i rebuild her.

[ChrisF-dude]

Just a thought as I was going to get a cam and headwork done on my EW before going ZC; If I remember correctly, on the old Turborex web site it said JG Engine dynamics ported and polished the head. I think it also said the improved breathing allowed an additional 30hp? So if you are getting a SOHC cam for the head you MAY want to open it up to breath better. And when I had my EW, the aluminum flywheel and crank pulley helped it rev a bit quicker but is still no match for the ZC. I was also under the impression the 85 Si had a little hotter cam than the 86-87? I could be wrong, it happened once before. Kinda like the 90-91's have a hotter cam than the 88's or vice versa. BTW, the Chikara tork-step header was a GREAT improvement on my EW. Buy it painted and just have a machine shop jet coat it (cheaper). Good luck.