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im looking at shaving the head on my 99 ls and also doing a port and polish. what kind of hp can i expect w/ i/h/e along w/ this???
 

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12-15 whp in the powerband location you specify (for an average porting job)...18-22 whp in the powerband location you specify from an outstanding porting job matched to your package. If it's less than 12 whp and the powerband is peaky and narrow, they messed up big time and have no clue about what they are doing.
 

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hey MD... 12-22 hp from just a porting??? got any info on what taking about 25 thousandths off the head would do???
 

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you make it sound like he's made of money....yeah, spend another $650-1000 on cams and $200 on valvesprings and maybe $150 on retainers and throw them into a $600-700 headporting job...can we get a grip on reality please?

25 thousandths will give you about 0.7-0.8:1 static CR on a stock GSR and about 0.4-0.5:1 on a stock LS.
 

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hey md. i just bought a set of crane cams. they are the street/strip version. i was wonders what the max would be on shaving the head and also what kind of hp could i expect from cams, short ram intake, 4-1 header, pulleys, and exhaust? any ideas? without shaving the head.
 

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You're going to turn him into a horsepower calculator now?
 

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I have some general comments first bfore answering your question:


you'll have to call Crane and get the intake cam's ABDC valve closing degree spec and plug it into the Dynamic Compression calculator (use the search function and that term in MD Tech Corner Forum and you will find the thread where I linked to the calculator). Then you will see whether you have sufficient static CR for that cam. As a general rule, you'd like to have at least 10:1 dynamic CR for an N/A application that is seriously making big power.

Be careful about "adding up hp". That's the old newbie hp accounting by parts mentality that you don't want to fall into. This incorrect way of thinking goes like this: I'll buy this part (say a headporting job) and it will make this much hp. Then I'll buy this other part (say a cam) and that will make this much hp on top of that. So my net gain in hp is the sum of hp gains from each part, right? WRoNG!

you are looking for things that work well together. you are basing it on sound engineering principles. Then the combination will gain a certain amount together. What that exact amount will be is based on observing similar engines with that package. So for me to spout off hp gains from parts is as good as pulling a number out of a lottery. If a headporting job was made for a specific cam spec (which it should) then gains on the order of 20-25 whp are not unheard of. So when a GSR with i/h/c/e (with the proper size for these) receives the cam/head addition, power figures around 180-185 whp are common. A more aggressive cam doesn't necessarily guarantee more gains if your CR does not provide enough dynamic CR or internal cylinder pressure to turn the crank at the right time.

You can have too much cam for the engine. People don't warn you about this.

If you want to learn some basics about cams, check out this month's Hot Rod magazine. Yes it deals with domestic cams. But if you ignore the bits about overhead valve lifters and SOHC stuff, the concepts about having not enough cam and having too much cam for the engine applies to our engines as well. It's a good teaching tool to read about before you run off and get a cam.


Just remember that our import standard for comparing cam duration specs between different manufacturers is at 1mm valve lift and not the domestic standard of 0.05 in. valve lift.

So if you see a certain number of degrees duration at 0.05 in., to compare that number to another cam's duration , this other cam must also report their duration at 0.05 in. You can't compare a cam spec in "adverised duration" or at 1mm lift to one that is not reported in that way...example: a cam with 255 degrees duration at 0.5 in. does NOT necessarily mean that it has more duration than another cam with 245 degrees duration at 1mm lift. You have to compare apples to apples...not to oranges. Again import cams are compared between different manufacturers at 1mm valve lift as the accepted standard. If they use durationat 1mm valve lift then you can see which one has truly more duration.
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Now to answer your specific question:

The Crane cams are very mild cams. They are just a little bit better than the 2000-2001 ITR/ CTR cams. In a stock CR package they would be okay but I find it difficult to justify shelling out the cash for something that is only a little bit better. Compare the spec to say a Skunk2 Stage 1 or a Crower 63403 cam which can work with stock CR and you will see what I mean..the Cranes are not "that" aggressive and therefore won't wow your socks off. You can get the same thrill IMHO with ITR cams and spend a little less.

Just remember also that warning and rule I told you about in terms of newbie hp accounting and that the wilder the cam spec, the higher the CR you will need as well (bling bling: must buy higher CR pistons with that wilder cam).

cheers
 

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Just so you know there is a wear guide on the honda heads, on the Ls its at one end or the other. It is a U shaped line with a circle in the middle, the head can be milled down to the bottem of that. The block is the same way. From my experiance on a itr, fully cc motor, milling the head and block all the way down, the compression ratio was only brought up one full point. ie:10:6:1 to 11:6:1 although this compression was never run on this perticular motor, thats what the comp. rat.was before getting low comp. pistons. Not exactlly sure about HP #, maybe 20 to the crank after raising one full point. Hope this helps
 

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Michael. What do you do for a living? You know sooooo much about integs. I'm new here and so far the only replys I like to see is either you or BoostControl
 

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I just put some srp 10.5:1 pistons in my LS and i am about to have my head shaved and im wondering when do I have to start worrying about valve to piston clearances? would 25 thousandths be ok?
 

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20 thousandths is the same as taking off 2 layers on a stock headgasket. You'll probably not want to go any higher than that.

people who have gone to 35 thou as an inexpensive way to increase static CR find later on that some high ramp cams are incompatible because the clearance was reduced too much. Milling not only reduces your piston to valve clearance, it also changes the cam timing (i.e. it retards the cam timing, approx. 2 dgrees per 12 thousandths milled off as I recall but don't quote me on that).

I suggest you use a thinner headgasket rather than milling. Headgaskets can be swapped out if it doesn't work out but milling is permanent and you can't take it back.
 

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OEM, just take one layer off. Also, Cometic makes some good head gaskets.

Also, MD, I see earlier in the thread you are talking about VTEC cams while the original poster has a GS, not a GSR.
 

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furious94ls just had his head rebiult on his 94 GSR after bending 2 valves at the track a while ago. theres quite a noticable difference now. he's smoking 03 nissan maximas now.
 

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From getting his valves replaced?!?! Tell me how that's possible unless he was out of spec.
 
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