69 replies to this topic

[chris haldeman]

Yep that too!

[Jamz14]

I said suspicious; not scared.

 

Bench, I was eluding to another question in my post. I was asking about compensating for any mechanical retardation by the head being lower by changing the stock cam positions when at TDC. That is the direct question.

 

The eluded to question is a question that most mechanics ask or think about; are there, or could there be, a performance advantage by doing something other than doing it stock? In this particular case that means; is there a performance advantage by not having the cams in the stock position in reference to TDC?

[Brandon]

I said suspicious; not scared.

 

Bench, I was eluding to another question in my post. I was asking about compensating for any mechanical retardation by the head being lower by changing the stock cam positions when at TDC. That is the direct question.

 

The eluded to question is a question that most mechanics ask or think about; are there, or could there be, a performance advantage by doing something other than doing it stock? In this particular case that means; is there a performance advantage by not having the cams in the stock position in reference to TDC?

 

I'm 100% agreement on what you're getting at, but it is my understanding (I'm not the expert) it would not be a "techable" rule to claim cam position being one tooth off.  I liken it to being similar to minimum ride heights when you know how much bumping around we tend to do in SM.  That doesn't mean there might be a portion of the GCR as it relates to 'proper engine build' requiring accurate timing being implemented...I just don't know.

 

Regardless, with the other aspects of our engine specs being so stringently defined, I think there is very little left in terms of monkeying with the mechanicals (outside of head machining) that improves performance.

 

I'm a pedantic bastard: alluded to

 

** Elude == to evade and/or make unavailable

** Allude == to lead towards/provide direction

 

** Fetch's Dickshunairy

[Johnny D]

https://www.youtube....h?v=CcFIZF9ORRQ

J~

[Brandon]

https://www.youtube....h?v=CcFIZF9ORRQ

J~

 

Hahahahahahaha!!!!

[Jamz14]

Brandon, you are absolutely right and I am highly embarrassed by my grammatical errors.

 

Other than that; I am not worried in any way that setting of the cam position would violate any rules. It doesn't. I am interested in whether looking at this area might yield a performance advantage that I am not taking advantage of.

[Jim Drago]

I'm 100% agreement on what you're getting at, but it is my understanding (I'm not the expert) it would not be a "techable" rule to claim cam position being one tooth off.  I liken it to being similar to minimum ride heights when you know how much bumping around we tend to do in SM.  That doesn't mean there might be a portion of the GCR as it relates to 'proper engine build' requiring accurate timing being implemented...I just don't know.

It is absolutely "techable' and has been teched at Runoffs in the past on several cars, myself included. The timing belts sprockets were inspected and before removing the belt the tech inspector came and inspected not only belt location but also made sure the cam gears were attached to the cams in the correct mounting position.

[Jamz14]

It is absolutely "techable' and has been teched at Runoffs in the past on several cars, myself included. The timing belts sprockets were inspected and before removing the belt the tech inspector came and inspected not only belt location but also made sure the cam gears were attached to the cams in the correct mounting position.

Are you saying that if I offset the cam position by one tooth from the stock alignment that that is illegal? If so, can you point me to the section?

[Bench Racer]

Take a peak at the FSM installing a cam belt.

[chris haldeman]

Bench is spot on in his fsm response. All work must be performed too fsm specs unless spelled out specifically. More too the point I have tested belt installed off a tooth and it is too much advance or retard. Each tooth is I think 12deg and that is way too much. Typical loss of 7hp

[Jamz14]

Bench, give me a break. I can set the MECHANICAL timing to FSM spec as good as you and I am as familiar to what it says in the FSM as you. That isn't the question.

 

The questions are 2.

 

1. Show me the GCR that prevents me from slipping one or both of the cams in one direction or the other when the engine is at TDC?

2. Is there a performance benefit for retarding or advancing one or both cams from their factory defined stock settings when at TDC?

 

So no one is confused; I am not talking about changing the number of teeth in between the cams on the belt. For instance, I am not suggesting that we should set 18 teeth between the cams on the belt. I am asking these question in reference to when the engine is at TDC is there a benefit and a rule that covers me rotating one of both of the cams away from their factory defined position ( still with 19 teeth in between the cams just with one rotated in one direction or the other one tooth away from that cam being in the FSM defined position for TDC).

 

I am not asking anything original. People know the answer to both those questions. I just don't ( at least not the performance question, I firmly believe that there is no rule that prevents me from changing the MECHANICAL timing). I haven't been doing this game as long as others.

[Jamz14]

Chris, just saw your post as I posted. Thank you. I dont feel that the to FSM specification is adhered to or used in that way. If that is the case then you can be DQed for not torgueing your hubs to factory spec, ETC. the spirit of that rule was to prevent machining outside spec. Not tuning IMO.

[Jamz14]

Chris, Geometry was not my strong suit. Does this makes sense; if one tooth is 12 degrees, would that mean that there are only 30 teeth on a cam gear? I'll count tonight. But if there are more than 30 teeth, can a one tooth difference equate to 12 degrees?

[Tom Hampton]

James-

 

the rule is 9.1.7.c:

 

...

 

Assembly, rebuild, and refurbishment procedures, and all associated dimensions must adhere to the published factory service procedures, except as otherwise stated in these rules. No components may be added or omitted from those specified by the published factory service procedures. All components must be standard dimensions. It is permitted to use industry standard procedures to repair damaged non-engine components (e.g., welding a transmission or differential housing).

 

...

 

I wish people would stop quoting "spirit".  Rules don't have spirits.  They have words.  Note the words above list "assembly" and "rebuild".  I don't think the FSM procedures allow for "assembling" or "rebuilding" the engine with the timing belt off by a tooth. 

[Jamz14]

Let me change spirit to intent of the rules then Tom. Rules do have an intent. The "words" are the mechanism for imparting intent and understanding. Many rules in our class and other classes have had to be rewording specifically because the intent was abused.

 

So when the FSM says I have to use a new drift pin when I rebuild the gearbox then I must use a new drift pin or be DQed? So all those running without top bolts in the tranny should be Dqed? Those that have zip tied certain parts on should be Dqed? ETC ETC ETC. With your logic not one of those is legal and I should protest you all and have you DQed?

 

Even reading the exact phrasing you posted above it seems that the intent is to keep people from modifying the parts themselves. Not in preventing us from using the parts we are allowed in creative ways.

[Johnny D]

You get Dq'd from a stated rule, not a stated intent.

J~

[Tom Hampton]

I don't agree with your position on "intent" either.  Its the same side of the coin of my pet peave. 

 

I can't prove you used an old drift pin.  But, I can prove that you assembled your timing belt wrong.  I can point to the page(s) of the FSM where it clearly describes how to ENSURE that the timing belt is installed with the correct timing (only one way), and I can show (through inspection) that your timing belt is NOT installed iaw the FSM.  Thus you got some 'splainin' to do.

 

You say "should be DQ'd" several times.  I would replace "should be" with "can be" or "are at risk of being".  "Should" implies a judgement---aka you are a cheating bastard and should be DQ'd.  I'm not judging.  I'm just saying that the rule is there, and where it can be PROVEN that you didn't adhere to it, you can be DQ'd. 

 

We all know there are "protests" and there are "weeny protests".  We all also know that being known for filing weeny protests isn't going to be good for ones racing experience. 

[Jamz14]

No problem then Johnny. Then I can righteously have people DQed for their hubs not being torqued at factory spec. Yes I might be an asshole, but you can sure bet after a couple events with people DQed per the rules words that the words would change in a heart beat. You know, like Mazda Raceway last year.

[Jamz14]

Ok Tom, but I CAN prove that your hubs are not torqued to factory spec.

[Tom Hampton]

If that were true, I have no problem with it.  In my specific case, no you can't.  Because mine ARE torqued to FSM specs---its part of my pre-race inspection checklist, along with all other suspension and driveline nuts/bolts (all of which are torqued to factory specs).  The exception to that would be the alignment cam bolts which are tightened to the "jesus f-ing christ" level---protest away.