SCCA ITS built L engines?

[turbogrill]

Hi,

 

Considering the age the Z cars seems to be a popular SCCA ITS engine.

 

It's a bit surprising since the engines has to be more or less stock under ITS  rules. And we all know what a turd a stock L28 is..

 

But I remember seeing a post on this forum that ITS built L28 actually had significantly more than the whooping factory 135hp.

 

Anyone has any more details about these engines?

 

How is it possible to extract any power out of the L28 if you are not allowed to touch the cam?

 

(I guess it applies to the L24/L26 as well)

[madkaw]

Good thing TonyD doesn’t get on here much anymore or you would get schooled on this. I believe I’ve read 208 hp on an ITS motor in its day, but I could be wrong . 

Voodoo and secrets that builders won’t ever give away. 

I believe in the rules there’s allowances for removing metal in certain places - head !

CR would be for race guess I’m guessing . 

Hell- maybe I’m talking out my ass

[ryant67]

Excruciating attention to detail would be my guess.  Everything perfectly balanced, precise clearances, removal of sources of parasitic loss, and the willingness/ability to push the engine above the RPM levels of a street build.  

 

I would imagine that ITS racers have engines with lifespans measured in hours, and they get treated with a much higher level of maintenance, as well as regular rebuilds.  As such they can be pushed much harder and survive.

 

It would be interesting to get an experienced answer.  

[turbogrill]

2 hours ago, madkaw said:

Good thing TonyD doesn’t get on here much anymore or you would get schooled on this. I believe I’ve read 208 hp on an ITS motor in its day, but I could be wrong . 

Voodoo and secrets that builders won’t ever give away. 

I believe in the rules there’s allowances for removing metal in certain places - head !

CR would be for race guess I’m guessing . 

Hell- maybe I’m talking out my ass

 

21 minutes ago, ryant67 said:

Excruciating attention to detail would be my guess.  Everything perfectly balanced, precise clearances, removal of sources of parasitic loss, and the willingness/ability to push the engine above the RPM levels of a street build.  

 

I would imagine that ITS racers have engines with lifespans measured in hours, and they get treated with a much higher level of maintenance, as well as regular rebuilds.  As such they can be pushed much harder and survive.

 

It would be interesting to get an experienced answer.  

 

 

But how how how how how

 

 

These are the obvious mods that are allowed:

- Megasquirt (using dizzy not trigger wheel)

- Headers + Exhaust

- Cold intake

- .040 over (but same shape, so no flattops on N47)

-  Intake match to head

- Valve guide can be changed (but no head work?)

-  Retard / advance cam (at least it's not mentioned not to)

 

How do you get 208 hp from that??

 

Tony where are you?

 

[NewZed]

I think that John Coffey had the high HP ITS engine.  Search his old posts.

 

Here's one example, but it doesn't describe the engine building just the results.  He mentions 200 HP.  But I remember reading some of his other posts.  It is about attention to detail.

 

Edit - also search just John Coffey and horsepower.  Every now and then he would post his best bang for the buck list for creating power from a stock starting point.

 

 

Edited July 31, 2018 by NewZed

[SleeperZ]

19 hours ago, turbogrill said:

Hi,

 

Considering the age the Z cars seems to be a popular SCCA ITS engine.

 

It's a bit surprising since the engines has to be more or less stock under ITS  rules. And we all know what a turd a stock L28 is..

 

 

Never heard anyone call any version of the stock L28 a "turd".  They are all very good engines, including the L24 and L26, heck even the LD28.

[turbogrill]

1 minute ago, SleeperZ said:

 

Never heard anyone call any version of the stock L28 a "turd".  They are all very good engines, including the L24 and L26, heck even the LD28.

 

I think they are a little slow in stock configuration compared to a modern engine. 

But I agree, I also think they are great engines. Durable, easy to work on and has a surprising amount of potential.

 

But either way, how do you get 200hp out of a stock L28? Mystery to me

 

 

[Chickenman]

Two things you have to do. 

 

1: Download the current SCCA rules and go over them with a fine tooth comb. Have preconceived notions about nothing. 

 

2: Details, details details. . You blueprint and maximize every thing. When in doubt, find a friendly Racer. Or ask a scrutineer. 

Quote

- Megasquirt (using dizzy not trigger wheel)

- Headers + Exhaust

- Cold intake

- .040 over (but same shape, so no flattops on N47)

-  Intake match to head

- Valve guide can be changed (but no head work?)

-  Retard / advance cam (at least it's not mentioned not to)

 

How do you get 208 hp from that??

 

 

^ That actually gives you a fair amount of Leeway. The MS (or any other brand Programmable ECU ) is a HUGE improvement.  Proper AFR's are essential. And the ability to program Spark curve helps as well.

The Exhaust and headers allowance really helps. Probably more head work going on than you realise. Port matching is allowed, so is CC combustion chambers, Multi-angle valve and seat grind.  Replacement of Valve guide allows some gains ( Tapered guides ) and likley Tuliped Valve Stems  are allowed. 

 

Reduction in friction is also a big area. Reduction in ring tension, engine build ( Bearing clearances )  to use lightweight synthetic oils. All are areas' for gain.  

Edited July 31, 2018 by Chickenman

[Chickenman]

18 minutes ago, SleeperZ said:

 

Never heard anyone call any version of the stock L28 a "turd".  They are all very good engines, including the L24 and L26, heck even the LD28.

 

 Exactly. I ran ISSCC D-Prod racing years ago, and their engine rules are basically the same as SCCA. We were twisting 7,2000 out of L24's back then ( Late 70's ) and making good power. Engines last forever. 

[turbogrill]

1 hour ago, Chickenman said:

Two things you have to do. 

 

1: Download the current SCCA rules and go over them with a fine tooth comb. Have preconceived notions about nothing. 

 

2: Details, details details. . You blueprint and maximize every thing. When in doubt, find a friendly Racer. Or ask a scrutineer. 

 

 

^ That actually gives you a fair amount of Leeway. The MS (or any other brand Programmable ECU ) is a HUGE improvement.  Proper AFR's are essential. And the ability to program Spark curve helps as well.

The Exhaust and headers allowance really helps. Probably more head work going on than you realise. Port matching is allowed, so is CC combustion chambers, Multi-angle valve and seat grind.  Replacement of Valve guide allows some gains ( Tapered guides ) and likley Tuliped Valve Stems  are allowed. 

 

Reduction in friction is also a big area. Reduction in ring tension, engine build ( Bearing clearances )  to use lightweight synthetic oils. All are areas' for gain.  

 

This is a new level for me, I am more of a slap everything together while kids are a sleep and hope it works (so far it has). But only built 2 engines so far, maybe the 3rd can be a little more detailed.

 

It's very cool, seems like there is plenty to learn.

[clarkspeed]

Yes, devil in the details.  Basically doing everything the rules allow and everything you would read in a balance and blueprint book.  Every clearance checked and rechecked.  Every tolerance maximized and duplicated.  A lot of other SCCA classes and pro-racing follow the same recipe.  And the best dyno proven parts that are open like exhaust.  It is hard to get there building yourself but >200 at the crank is very possible on a 2.8, but don't underestimate running a 2.4.  Higher rev limit with lighter weight is as fast and sometimes faster.  

 

I just refreshened a 2.4 ITS engine of unknown origin.  Nothing special there. I did see a few things that looked "different" but provided no advantage.  Not too many Z's running ITS now that the price has escalated.