Randy is correct ! Engine discussion here.
1Zz vs. 2ZZ vs. 4AG vs. Honda ??
All reduced to 1600cc per existing rules.
Randy is correct ! Engine discussion here.
1Zz vs. 2ZZ vs. 4AG vs. Honda ??
All reduced to 1600cc per existing rules.
Steve - thanks for answering my EMail - I'll post your response in a minute. I read a lot of info on the web, and it appears the 2ZZ head geometry is better than the 1ZZ, but the valve actuation may be a problem for higher revs. The 2ZZ block is an aluminum matrix closed cylinder type - I read the pistons have a special coating on them - lots of diferences between the engines.
Doesn't the Honda rotate the other way?
Anyway, the class philosophies need written/re-written for all our formula classes (except perhaps FS). In FA, can we allow any 4 cylinder engine but provide a maximum intake venturi size for all engines? - and pretty much leave it at that?
Most of our formula classes need some re-invigoration. To me, we need a mix of spec and (more) free classes.
Intro: I think that my questions below are somewhat related to this topic. I'm not too knowledgeable about the current engine situation. A statement I've read lately seemed to indicate a new situation with TRD? Are they the only provider for Toyota FA engine parts? Are there recognized problems with current atlantic engines? Enough so that new engines will probably need to be introduced soon?
Anyway - to my FA Engine questions:
I'd like to get a feel for the mileage between rebuilds, rebuild costs and HP for the most common atlantic engines.
My engine builder (Sam Nelson, Cumming, GA, who I'm happy with), suggested that when we rebuilt my supervee engine we go with a less radical cam than used by the pro supervee engines so that I would have more reliability (and lower RPM torque) for my regional SCCA racing. Sam recommends rebuilds around 10 hours/1,000 miles, depending on the age of components (i.e., which parts were new in the last rebuild).
Someday I may get a "true" atlantic and since I'm very budget conscious (I really shouldn't be in FA to tell the truth, but ...), I'd like to know which engines would be best for me.
From what I know, these are the most common engines found in used atlantics:
Cosworth
Toyota (injected)
Toyota (carbed)
Mazda 12a
I'd really enjoy hearing your opinions about the pros and cons of each.
Thanks.
Racer Russ
Palm Coast, FL
From what I understand, Toyota is discontinuing their involvement with the pro series, and with that the pro-spec parts supply may dry up unless they decide to continue producing components to support club racing. But unless you are building a pro-spec motor, there are not many TRD parts that go into building a club Toyota motor. Even the injected club motors these days are so hacked up and modified that they may as well have been produced from scratch. But as for problems with the current motors: yeah, they're expensive grenades...Questions from RussMcB:
A statement I've read lately seemed to indicate a new situation with TRD?
Are they the only provider for Toyota FA engine parts?
Are there recognized problems with current atlantic engines?
Enough so that new engines will probably need to be introduced soon?
I'd like to get a feel for the mileage between rebuilds, rebuild costs and HP for the most common atlantic engines.
From what I know, these are the most common engines found in used atlantics:
Cosworth
Toyota (injected)
Toyota (carbed)
Mazda 12a
I'd really enjoy hearing your opinions about the pros and cons of each.
We have been rebuiding our Toyota 4AGE motor at around the 1000 mile mark, at a cost of $5k and an output in the 250hp range. Our last rebuild was actually around $8k, but I had to replace a cracked cylinder head (the head was quite old) so there were costs for the brand new casting, porting and general prep work.
Pros: assuming your motor was built by a professional, it is a very well developed motor whose behaviour is predictable within a given operating range. The engine is not fragile as long as it is not abused, and you don't have to fiddle with the thing in the car. The most in-depth our engine maintenance got was pulling the plugs to check ballpark mixture and we changed the main jets about a half dozen times last year. That's it. The Ralt has been very well developed with this engine package as well, so there is a lot of setup knowledge floating around out there, which may have to change slightly in the face of new CG locations/heights and engine tractability, etc. That may not be so serious an issue for teams/drivers that are adept at setting up the car, since they're going to adapt to the circumstances anyway. But for a newbie or someone not as technically inclined, plugging in a motor with different mounting locations and block flexibility characteristics may be the difference between being able to follow somebody else's advice and being lost in the woods.
Cons are that they don't last too long and they're expensive.
Ren
Having driven the class for longer than I care to remember (Argo, RT-4, Reynard) and used both Toyota and BDA, my vote strongly favors a Jennings Cossie. I have nothing bad to say regarding the Loynings Toyotas. I preferred the installation and maintenance associated with the Cossie.
Charlie Warner
fatto gatto racing
'Cause there's bugger-all down here on earth!
FYI - Here is Steve Jennings reply to an earlier Email of mine:
Robert: I have been doing a 1ZZ project for off road Class 10 Baja 1000
racing for almost 3 years now. The team owns a Toyota dealership so must
use a Toyota. We looked at all the small Toyota engines and chose the
1ZZ over the 2ZZ. The 2ZZ valve actuation mechanism is not suitable for
racing.
It is obvious ( to me ) that the 1ZZ has the potential to make more hp,
torque, rpm and weigh 20 lbs less than the 4AG for a lot less $ than
the current $60k one guy is paying for his "special" 4AG:
Very basic stuff like the valve included angle, port angle and shape,
tappet size and cam drive (chain) are all much better than the now
antique 4AG.
So far we have bored it out to 82mm and de-stroked it to 1650cc for the
class. At 1600cc the rod to stroke ratio will still be very close to 2:1.
My estimate is that if the 4AG has been developed to 100% then the 1ZZ
will equal that level of performance at 75% .
It is ok if you want to post this reply at apexspeed.
I was down at Sebring this week an saw alot of the new Pro Mazda cars along with an FA with the older version Madza motor. The Madza seemed only slightly slower out of the corners but had good power compared to the Toyotas. I was told that it lacked a little grunt but was very competitive.
It is my understanding that the new Pro Mazda motor is not legal yet in FA, is that correct?
Why arn't more guys going to Madza. I was told that they run forever and make good power?
I also saw an F3 car running in FA with a VW motor. Car looked really nic but they were having head gasket issues.
(Take all of my answers with a grain of salt - I don't know anything for sure).Originally posted by Dan Kennison:
It is my understanding that the new Pro Mazda motor is not legal yet in FA, is that correct?
I've heard from someone considering a new pro Mazda that the performance potential of the engine (or maybe it was the stated HP) was enough above current FA levels so that they didn't think the pro Mazda would be allowed in Club FA. I think it may have been rated at 280 HP, but I could be wrong.
I've heard that to get a lot of power out of a 12A (the legal FA engine), they have to be modified enough so that a lot of the inherit reliability is negated.Why arn't more guys going to Madza. I was told that they run forever and make good power?
Interesting. I think the VW is in the list of approved FA engines (Cosworth, Toyota, etc.). And I guess the F3 chassis could fit within the Club FA chassis rules, so I shouldn't be surprised. I am pretty sure that to go above 1600cc with the VW engine the whole car must fit the old Pro Super Vee rules, which are pretty different from the "regular" Club FA chassis rules. If the car fits Pro Super Vee rules, the engine can be 1835cc.I also saw an F3 car running in FA with a VW motor. Car looked really nic but they were having head gasket issues.
Racer Russ
Palm Coast, FL
Charlie, what is your current FA mount?
Stan Clayton
Stohr Cars
In answer to my direct question regarding the availability of TRD supplied parts for the 4AG in club racing, Tom O'Connor sez that Toyota will continue to supply parts. They currently have about 35 Cylinderheads and more ( than 35 ) blocks on the shelf. He reinforced that Toyota intends to continue selling these parts. If there are any parts besides heads and blocks that can't be sourced somewhere else, please let Tom know so he won't be caught short. He added that Toyota is commited to PRO Atlantic thru 2005.
Steve
Steve,Originally posted by S Jennings:
In answer to my direct question regarding the availability of TRD supplied parts for the 4AG in club racing, Tom O'Connor sez that Toyota will continue to supply parts. They currently have about 35 Cylinderheads and more ( than 35 ) blocks on the shelf. He reinforced that Toyota intends to continue selling these parts. If there are any parts besides heads and blocks that can't be sourced somewhere else, please let Tom know so he won't be caught short. He added that Toyota is commited to PRO Atlantic thru 2005.
Steve
Where are you getting ported heads?
Would you care to talk to RFD about or engine builder program?????
Curtis
RFD
Curtis, What kind of difference on the flow bench do you get between a well ported 4AG cylinderhead and a Cosworth BD cyl head with 1.36 and 1.18 ( or there abouts) valves and a 3.344" bore ?
Steve
Someone sent me a private message and was asking about the F3 car I saw at Sebring. It was forward to me without a return email address.
The car was being preped by Cap MotorSports. It was classified as FA for the National SCCA race.
if you need any additional information: Dan.Kennison@PremierHolding.com
Dan
Stan,
My current atlantic mount isn't. I did about 16 years with an Argo, RT-4, and finally Reyanrd 89/90. Switched to historic (Shadow F1) and BOSS (Reynard F3000) two years ago. Have a CSR Lola Olds to keep in practice with Club races.
Charlie Warner
fatto gatto racing
'Cause there's bugger-all down here on earth!
Ted,
I seem to recall that you wrote in another thread that you are turning your Cossie to 11,500? Is that right, and could you tell us more about the engine's particulars?
Thanks!
Stan Clayton
Stohr Cars
Curtis: I didn't mean to embarass you with my questions about air flow numbers in two specific FA engines. I do not know the answer and I have been doing these engines for a long time. Word about your work quality is starting to leak out and we expect you to be busy. You will certainly get a shot at the next FA Pro engine cylinderhead, if there is one.
Steve
Steve,
You didn't embarrass me, .. truth is, .. I didn't know exactly, .. and didn't want to guess. So I was working on finding out, .. exactly. I respected the question, .. a VERY good one. An engine builder who is sharp enough to ask something like that, . . . is one I'd like to work with.
So, I have a few Toyota heads that I've done some development work on and looks very good, .. I have a Cosworth head that I'm starting my development on, .. as well as a few others. I'm hoping to move into others as well, ALMS, GT etc.
If "word is leaking out" then I would hope you've heard details of how I work with engine builders. It's a close working relationship.
I use computer models to help work out volumetric efficiency with crank degrees, piston speed and cam designs. There's much more to this then just making a head flow well, .. where it flows well and the balance between the intake and exhaust flow, .. as well as cam all effects the volumetric efficiency. Of course it all comes down to the dyno and race track, .. and because of this requires a close working relationship between myself, .. the engine builder and ultimately the racer.
BTW, .. Rennie if you see this, .. .. e-mail me so I can e-mail some of the Run Offs photos.
Curtis
Curtis Boggs
RFD
Is "Leaking out" a good thing when talking about a head porter? [img]tongue.gif[/img]
Curtis,
Rennie's email address is rennie@rennieclayton.com
Stan
Stan Clayton
Stohr Cars
No, .. .. but don't ask me if I give good head.Originally posted by Scott Gesford:
Is "Leaking out" a good thing when talking about a head porter? [img]tongue.gif[/img]
Curtis
Curtis, Speaking of leaking out.....I have a used, ported 1ZZ head that is , you guessed it, leaking out. Would you be interested in flow testing it along with your BD and 4AG samples "in the interest of science" ?
Steve
Steve,Originally posted by S Jennings:
Curtis, Speaking of leaking out.....I have a used, ported 1ZZ head that is , you guessed it, leaking out. Would you be interested in flow testing it along with your BD and 4AG samples "in the interest of science" ?
Steve
Send me every head you have to flow, .. in the "interest of science" if you like, .. .. the 1ZZ i would be VERY interested to see.
Who ported it ???
I'm very open to development projects, .. and of course that is what I love about cylinder head work.
Curtis
RFD
703-541-0565
Curtis, a used ( and leaky ) 1ZZ toyota cylinder head was sent last week to your shop. (FedEx ground) Let me know if you need any other stuff to do the flow test. And no, there is no inlet manifold yet for this piece.
Steve
Steve,Originally posted by S Jennings:
Curtis, a used ( and leaky ) 1ZZ toyota cylinder head was sent last week to your shop. (FedEx ground) Let me know if you need any other stuff to do the flow test. And no, there is no inlet manifold yet for this piece.
Steve
Got the head, .. thanks for sending it, ..
I've got to make a valve opening fixture for this head, .. but not a problem.
Perhaps you should send me an e-mail with some details, ..
bore, stroke, cam specs, .. etc. For the software I use.
curtis@cboggs.com
Just from looking at it for 2 minutes, .. I can improve on this.
Curtis
RFD
Curtis, Use Toyota 4AG cams and a 82mm bore .
Steve
I was wondering what type and year street car our Toyota Motor originally came out of. What kind of horsepower it had before all the modifications. It seems like it must have been quite an old model.
Anyone know?
Dan Kennison
I think it was the first generation rear engine MR-2. As a production engine it was probably not the best choice but hind sight is 20-20! Before the Pro series went to Fuel injection people were twisting these things two super high RPM's and the resulting ventilated blocks were making Toyota look bad-I think the company pitch at the time was "Oh what a feeling!"- yea like BANG! So when they came out with the FI and the ECU they could build in a rev limiter to help preserve their image.
IIRC, the official TRD racing version of the 4age was based on the 1986-7 supercharged 4agze block and head. The block has thicker walls and more webbing, while the head was the large port, thick walled casting (though it isn't real "thick"... ). New blocks and heads are still available from TRD, but I understand that they won't be casting more of them.
A well-built 4agze can be safely revved to at least 10,500, but has several fundamental design shortcomings for an all-out racing engine. Principal among them are a too small bore and a too long stroke for a 1600cc engine.
I expect other engines to take over from this 20 year old design in the next few years.
Stan Clayton
Stohr Cars
Stan
What would you suggest for the next SCCA FA engine ?
Steve
Steve,
In my opinion the 4age (and the 1zz and 2zz by extension) suffer from their road car origins, which emphasize low- to mid-range torque over high RPM horsepower. I have read that you consider the newer Toyotas superior to the 4age, and don't doubt that's true, but I still think they suffer from a bore that's too small compared to their stroke for an all-out racing engine. Personally, I probably wouldn't change from a 4age to a 1zz for an Atlantic engine - there isn't enough to be gained in my personal opinion.
I favor the highest possible RPM in all-out racing engines. To me that argues for a large bore, short stroke engine, such as the Cosworths offered by you and others. A bigger bore allows for larger valves, lower peak piston velocities, and a host of other benefits. The 4age (and 1zz-2zz) have a 0.95 stroke/bore ratio (at a nominal 81mm bore and 77mm stroke), while a Cossie at 90mm bore and 63mm stroke offers an inherently superior 0.70 ratio. This not only allows for much larger valves, but allows the engine to rev to 12,800 RPMs while maintaining the same average piston velocity as the 4age at 10,500 revs. Add a more favorable rod ratio and the benefits multiply.
Now, whether that is "the next SCCA FA engine" or not remains to be seen. After all, lots of engines are eligible. If I was starting over, though, I would certainly give this some serious consideration.
Regards, Stan
Stan Clayton
Stohr Cars
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