So here's what I'm doing for the engine as part of my "GT style" conversion. First and foremost, I figure that an engine in a GT style car has to be rev-happy.

So, here's what I'm putting together, with the help of my trusty wrench, Ron Green of Campbell Gararge in Montreal:

Short stoke 2.5 Porsche engine:

1) Used 7R engine case, align bored, Timeserted, shuffle pinned
2) 90 mm JE pistons, 10.5 compression ratio
3) 90 mm replated Nickasil cylinders, sourced from EBS
4) Standard piston ring set
5) 66 mm counterweighted crankshaft
6) GE 80 camshafts
7) EBS racing valve springs
8) EBS valve spring retainer set for above
9) 2.0 connecting rods
10) ARP rod bolts and nuts for above
11) twin plugged heads
12) Electromotive HPV twin ignition
13) Turbo lower valve covers
14) front mounted ol cooler with "GT Style" installation
15) new bearings and gaskets all around
16) miscelaneous engine parts, stock.

I still need to figure out what to do with the port sizes in the head. The target is to have a 8,000 rpm redline, and 250 hp, although the redline is more important than the hp to me.

So that's the plan. I pulled the trigger on the hard parts above today. ( I already have the crank and the miscelaneous parts).

Induction is going to be 40 mm PMO carbs, jetting to be determined.

I'll post to this thread as progress is mad on the engine.

Michel Richard

most of the race 2.5 go with 46's one locally went to pmo 50's. 2.5 at 8k is a large air pump.

Greg,

I hear you. To me, this is mostly a street engine, with a little track time, so I don't want to lose tractability. I'm told that the GE 80 cams on that engine should still provide smooth idle.

The 8,000 rpm thing is mostly because I find high reving engines to be thrilling. If I miss a few hp because of the small (relatively) carbs, so be it. Still, if you tell me that 40 mm is much too small, I'll certainly investigate. I would think that Richard Parr at PMO should have good data on these things.

Michel

I would check them out, little to prove my point but as you open those 40's I think that you lose some of the venturi's effect. Air speed with 38's in a 40 or 38's in a 46..?? I'm a not a techie by any means and my 40's despite spending nice money getting them rebuilt never seemed to "fit" the motor. The 46's went from a 2.9 to my 2.5 and I never touched them again.

Check with some one who really knows, unlike myself!!

8,000 is to high for a mag case. you will walk the crank right out of the case if you take it that high too many times. i have a 2.5 with much higher compression and could take it to 8,500 very easily. found no difference in power at over 8,000 then that at ~7,200, and the motor will last longer. which is a good thing when the motor cost 25,000.

agreed, but mine was in an old AL case, had red line set at 7k and rev limiter at 7500.....based on my cam not much more up there power wise, but damn it sounded good.

Sounds fun. If I ever build a new motor for my current 914, it would probably be an "old school" 2.5 alum case w/ Webers...an MFI 2.8RSR spec would not be bad either...for now I'm saving my pennies and hoping this one doesn't go BOOM too soon.

I agree with Greg, I would look at a bigger carb and then get some custom venturies to keep the velocity up. You could go with a little higher compression. This will help get some of the bottom end back. Do not worry about smooth idle. You can make any cam idle smooth with individual runner intake systems. I would throw a little more lift in there, but don't go up on the duration.
What is the duration on the GE80s? What are your plans for an exhaust system?

I would really look at a programable fuel injection system, it will allow you to get some more HP and drivability out of it.

I love the sound of the high revs, too.

I keep my limiter set at 7k and just smile when the motor tickles it.


KT

QUOTE (Brett W @ Dec 20 2005, 09:08 PM)

I agree with Greg, I would look at a bigger carb and then get some custom venturies to keep the velocity up. You could go with a little higher compression. This will help get some of the bottom end back. Do not worry about smooth idle. You can make any cam idle smooth with individual runner intake systems. I would throw a little more lift in there, but don't go up on the duration. What is the duration on the GE80s? What are your plans for an exhaust system? I would really look at a programable fuel injection system, it will allow you to get some more HP and drivability out of it.

I think an FI system is a better option. More control is gud.

i'm not that experienced with porsche engines, let alone the six's. but it seems that the 40's would be to small for 8k rpm. try jogging and breathing though a straw! it would most likely struggle to rev that high and flatten out. larger carbs will let'r breath. big carbs can be made to work.

You can make big carbs work better on the bottom end than you can make little carbs work better on the top end. You could always pick up the Vario Ram intake froma later model engine and control it with an aftermarket EFI. THis would give you both, torque and HP.

Id shy away from using the 2.0 rods. They are the least desirable rods to use on a performance engine. A few months ago someone on Rennlist was selling set of Carrillos, they have probably been snagged by someone already.

Pauter makes nice rods, but there prices go up everytime we buy a set

everything else about the build looks good

What heads do you have? I ported the heads on my personal engine 38/38, which is S configuration. the carbs I used before I went to EFI were 40 mm webers with 34 mm chokes.. btw my engine is 2.2

I had web-cam grind me a cam that is a cross between a S and 906 cam. which I timed so peak power occured at 7000 rpm. I got the cam timing zeroed to where I like it on the dyno

I havent built an engine with GE 80 cams yet but I have heard great things about them.

How long are the stock 2.0 rods? What kind of rod stroke ratio do they generate. You can use the rod ratio to tune some better low end drivability into the engine if you want.

For the price of those PMO's I'll get you a deal on an SDS FI system.

The PMO's are nice, but I wouldn't go back to carbs if you paid me.

/6 SDS is under $2k for crankfire...some MFI intakes, $400 in injectors...WB meter.
And you'll still have money left over.

OK,

Thanks for the collective wisdom. I'll comment and react to the various input:

First, generally, I'm a big believer in the fact that good enough is often just that: good enough. And in keeping a firm eye on the target.

Once again, I'm building a "sport" engine, one that I hope will be fun and exciting on the street, and be track-able once in a while.

So:
1) on the mag case and 8,000 rpm. I've taken my 2.2E built on a 5R case to 7,500 several times, without any problems. I'm pretty sure that the 7R case and upgraded valvetrain will safely take me to 8,000. Not for extended periods, and admitedly at a certain cost in engine longevity, but I doubt 8,000 will blow the engine. Sure, an aluminum case would be better, but they're hard to come by. They're non-existent, that I know of, in Montreal.

2) On the induction. In view of the number of comments above, I will certainly investigate. I think it's probably a good idea to at least start the engine with some carbs, because it's easy to do so. I would probably go to some sort of injection if I need to move away from the PMO 40s. The problem with fuel injection systems is that they sound good on paper and in theory, but they're a lot harder to get support for and lot harder set up. I agree that once dialed-in they'd be much easier to run.
I'll certainly talk to PMO to see what they think. And once again, I'm not looking for an engine that is at its most efficient at 8K, only an engine that is able to run and sound exciting when up in the upper reaches of the rev range.

3)on the 2.0 rods: Carillo and Pauter rods are approximately 5 times the price. And the 2.0 rods will work.

4) The heads are from my stock 2.2 E. We'll keep the valves (they've got less than 5,000 miles. Spoke to my mechanic last night, and his suggestion is 37/35 (IIRC) for a streetable engine. He says he would recommend another couple of millimeters if i was going for a screamer of an engine. That is one area where my mind really is not made up.

5) Mark, are you saying that a /6 SDS system that would do both injection and ignition would be under C$ 2K ? I have'nt bought the Electromotive system yet, so it's not too late.

Thank you all for your input.

Michel

I'd have to check it out...but I know a guy who bought a twin plug system 3 years ago and it was about $1700 US...so a single plug system must still be under 2k canadian.

PM me if your interested and I'll find out.

QUOTE

The problem with fuel injection systems is that they sound good on paper and in theory, but they're a lot harder to get support for and lot harder set up. I agree that once dialed-in they'd be much easier to run.

Both SDS and I will support you 100%.

The SDS will come loaded with the base program to your spec and injectors. I have 911 maps on file.

I could lend you my WB.

No Carbs needed for break in.

If your builder doesn't know squat about PEFI I'll talk him through it.

Hell... give me a bit of gas money and a place for the family to stay for the weekend and I'll come up and help you break it in.

As long as the car is "on the road" I can have it "dialed in" in one day.

SDS is simple.

I know Mark and some others like the SDS system, but in my opinion it is just that Simple. It works OK as a replacement for a carb system but it does not have the flexibilty to be tuned as well as a true standalone system such as the Autronic or Motec. There is plenty of support for each system. Many companies have systems for the 911 based engine.

In the beginning setup on the FI will be a little more laborious than carbs, but in the long run the mileage and drivability will always beat carbs.

Brett...Have you used an SDS?

What do you mean "true stand alone"?

QUOTE

In the beginning setup on the FI will be a little more laborious than carbs

That tells me you haven't used an SDS.

Mark,

Because I have the carbs, I would like start with those.

Does the SDS take care of the ignition too (i.e. is it an engine management system) or just the injection ?

Inviting you to come over and set it up in the spring is not impossible. Or me drving it down to your shop on the carbs. That is all several months away, though. (note to California guys: we got a foot and half of snow last week)

Can you point me to a good web page with details on the system ?

I already a pair of WB sensors, with the Innovate hardware. Oh, and please remember I'm doing a twin plug system, you were talking about single plug prices in your next-to-last post.

Michel

I know when Henry Schmidt put my 67S 2.0 together, he bothered to upgrade to the 2.2 rods over the 2.0 rods...
(For a STOCK motor no less)

I certainly don't have the experience or expertise regarding building... but I've heard more than a few times from people that I trust, that upgrading from the 2.0 rods is a very good Idea if you want the motor to last at more than casual rpm.

brant

Ill mention the connecting rods again.. Porsche reinforced the bottom end of the rods when they increased displacement from 2.0 to 2.2L. Your building a high revving 2.5. You said you planned on winding this engine out to 8000rpm, stout connecting rods are a must.

Ive seen a case almost sawn in half by a broken connecting rod, it aint a pretty sight.

2.2E heads are pretty choked .. the port size is 32/32. 2.7 US& ROW heads were 35/35. I had the heads on my 2.2 opened to 38/38

Id rethink the bottom end on the engine you want to build..I think lhe last set of pauters we bought was $1400

your engine build going to cost thousands more.. and if a rod lets go youve lost your total investment

rod length brings up alot of issues, longer rod to strock ratio will decrease the side forces that scuff the piston to the cylinder, this does reduce friction. it also incresses the tdc dwell time , this can cause problems of to much combustion pressure make for higher head temps and also detonation prone. Jake chime in her any time.
shorter rod to piston ratio is the anti to these, but also will have a stronger induction pulse due to the faster piston speed and accelerations. also same goes for the exhust. this can make up for a non-ideal intake port [size of port or valve or both] how ever the exhust could be hurt by not having time to flow all the gasses out.

just a big balancing act on a tight rope

that why not everone builds race engines and the good ones have engineering degrees

The SDS can't be setup to run in sequential injection, doesn't datalog to a laptop, can't interface with a laptop, and ghettos its way through several functions.

For example how can you tune an engine if you can't overlay read outs from a REAL wideband O2 sensor, map, tps, rpm, ect, iat, duty cycle? It would take all day to scan through a little screens worth of data. Where I can layup all of the fuel tables and ignition tables in 2D or 3D graph and quickly compare all data points without scrolling through single numbers. I can analyze trends quickly and make adjustments. Saving my customers money and time.

The SDS has no limp mode, no safety overides, can't effectively control Variable valve control and variable intake manifold operations, can't handle any pulse width modulated signals for devices utilizing such signals, no adaptive capabilities, no system diagnostic feature, etc.

For vehicle owners looking to upgrade to a simple fuel injection system and leave it alone, it may be OK, but I certainly wouldn't push it for any of my customers.

Is Autronic, Motec, Megaquirt, Hondata, AEM, etc the answer for everyone? No but they are better than the Simple Digital Systems. Your right, I have never, nor do I intend to waste my time and money with a system that will not do exactly what I need it to do.

I'm not as knowledgeable as I'd like to be.
but what Tim is saying makes A lot of sense.
if your going to have 15K+ into your motor, its at least thinking over!

brant

Sorry for the thread hi-jack. Tim and Brant are right.. RPM= Ruined People's Motors. If you are going to expect your engine to perform like a race bred engine you will have to take the proper precautions. You don't want to skimp on something as important connecting rods when you have 15K on the line.

Gentlemen,

The reason for going to 2.0 rods is that ARP does not make rod bolts specifically for the 2.2 rod. I'm not going to the 2.0 rod to save money: I already have 2.2 rods in my current engine.

I spoke to Henry Schmidt. He has a solution that uses 2.2 rods, rod bolts that ARP designed as steel replacement parts for 935 Titanium bolts, along with 928 rod nuts. The problem with that solution is that it's fairly difficult for me to source all those parts at a reasonnable price. Henry agrees that the 2.0 rod solution is a workable one.

On the other hand, the people at EBS say that plenty of 2.5 short stroke engines have been built using 2.0 rods and ARP bolts and that they work fine.

So, for a full race engine, I'm sure that using aftermarket rods is a better solution, but I think that for a hot street / some track engine, the 2.0 rod /ARP bolt solution will work. I'll go with those and let you all know how it works out.

Michel, I'm in awe of the progress you have made with this car. I'm glad for you that you acted quicker than me when you bought it. Your engine specs are very close to what I have in my conversion. I think your goals of 8,000 are optimistic. I know my engine will do it, but the dyno proved that peak hp was in the 6,800 to 7,300 range depending on jetting, fuel octane changes, and exhaust system. While it might sound great (it does, I think I have the sweetest sounding car), I think trying to achieve higher rpms on a consistant basis will not gain anything performance-wise. It will still perform and sound awesome at lower top rpm than what you are shooting for. In the end, go for what you want, as you will be the ultimate judge of your project. I always look forward to your progress.

T.C.

T.

Thank you for your kind words.

Peak hp around 7,000 with the capacity for 8,000 rpm would be fine with me. My objective is to have an engine that can do 8,000 once in a while, for short periods, even if hp drops a little at that point.

Which rods to you have in your engine ? What do you have for headers ?

Michel

T,

And what hp figures did you get ?

M

T,

You mention jetting, which seems to mean that you have carbs, which ones ? And what port sizes ?

M

2 liter rods
2.7 heads
ports where larger
specialty crank
46's
european race header
crankfire single plug
compression was about 10:1

190hp at the rear wheels
138 torque

peaked around 6500,ran all the to the 7500 cut off no problem...details would have to be looked up!!

QUOTE (Brett W @ Dec 22 2005, 01:23 AM)

The SDS can't be setup to run in sequential injection, doesn't datalog to a laptop, can't interface with a laptop, and ghettos its way through several functions. For example how can you tune an engine if you can't overlay read outs from a REAL wideband O2 sensor, map, tps, rpm, ect, iat, duty cycle?  It would take all day to scan through a little screens worth of data.  Where I can layup all of the fuel tables and ignition tables in 2D or 3D graph and quickly compare all data points without scrolling through single numbers.  I can analyze trends quickly and make adjustments.  Saving my customers money and time. The SDS has no limp mode, no safety overides, can't effectively control Variable valve control and variable intake manifold operations, can't handle any pulse width modulated signals for devices utilizing such signals, no adaptive capabilities, no system diagnostic feature, etc. For vehicle owners looking to upgrade to a simple fuel injection system and leave it alone, it may be OK, but I certainly wouldn't push it for any of my customers. Is Autronic, Motec, Megaquirt, Hondata, AEM, etc the answer for everyone?  No but they are better than the Simple Digital Systems.  Your right,  I have never, nor do I intend to waste my time and money with a system that will not do exactly what I need it to do.

Almost everything you said falls into the "who cares" department

QUOTE

sequential injection,

Very few cars run sequential injection, very little is gained by this. You forgot it’s also batch fired…again very little to be gained.

QUOTE

Doesn’t data log to a laptop,

This is the one I hear all the time....who cares besides techno geeks.
Sure it might come in handy on a high-end racecar, BUT a streetcar??? Come on. Just run the damn engine!

QUOTE

Doesn’t data log to a laptop

,
again see above.

PLUS your behind the times as SDS got sick of hearing these lame reasons, gave in and you can now download for data logging.

QUOTE

and ghettos its way through several functions

.

That’s a broad paintbrush with no substance...please explain the things it ghettos its way through.

QUOTE

For example how can you tune an engine if you can't overlay read outs from a REAL wideband O2 sensor, map, tps, rpm, ect, iat, duty cycle?

In about 10min with no dyno....I counter-point that how can the average person tune with all this clutter (and dyno time).

The average person is so over whelmed with information overload that they shy away from PEFI systems. Look at Michel here on this thread, I've told him that the SDS will start right up, within minutes I'll have the A/F dialled in (not that I'll have to tweak it much from the pre-loaded base line), BUT still he wants to break it in with carbs.

QUOTE

It would take all day to scan through a little screens worth of data.

Again the systems you use are not user friendly. Fast scrolling did take a day or so to learn all the tricks, but once you get the hang of it it's very easy.

In a race app I could make a major engine change and be dialled in good enough by about the 3rd corner. Can you say that?

QUOTE

Where I can layup all of the fuel tables and ignition tables in 2D or 3D graph and quickly compare all data points without scrolling through single numbers.  I can analyze trends quickly and make adjustments

.

Again more clutter that boggles the end users mind....not to mention as I said SDS now has data logging.

QUOTE

Saving my customers money and time.

I'm sorry but this is the biggest laugh! How do you save them Money! With dyno time? With a system they don't have a clue how to tune?
Please, it makes you money every time they have an issue because they can't figure out (or a just plain too scared to) how to fix it themselves.

QUOTE

The SDS has no limp mode

Doesn't need it. Besides water damage and a couple of the old style coil packs the only failures they've had have been user error.
For me 4yrs (2 engines, sold one) and I've never broke down.

QUOTE

can't effectively control Variable valve control and variable intake manifold operations,

Please again...what engine are we talking about?? I agree that if your running a V-tec or vario-ram this isn't the system for you, BUT in our apps this a TOTALLY USELESS feature.

QUOTE

can't handle any pulse width modulated signals for devices utilizing such signals, no adaptive capabilities,

Many systems can't handle every single system out there...you should always check to see if your components are compatible. As far as Tach's and MDS it's plug and play, no moduails to buy.

QUOTE

no system diagnostic feature, etc.

Almost every time SDS gets a return there's nothing wrong with the system. If there is something wrong it's a fried board because the user swapped the +/-.

I'm not saying SDS is the best system, as I don't think there is a "best" system. The biggest beef I have is the the SDS requires a bunch of in-line fuses that are not included, to me they should already be on the harness. Minor I know, but they just should be on it already.

I'm just pointing out some of your preconceptions are wrong and stating that a system sucks without ever having your hands on the system is just hear-say with no basis in fact.

TimT

Shut-up...Shut-up, Shut-up, Shut-up!
I'm on a rant!

Im just sitting on the sidelines eating some popcorn

That's OK...your system is also batch fired...he'll be knocking it next

Let me drop this little "bomb"

When I had an understanding of "how to" sync my triple Webers, it was less than an hour. Haven't touched the settings since last January.

Sure, jet cleaning, air cleaner washes...

I was just telling somebody a couple of days ago how simple it is. You could turn in all the idles and air corrections on my carbs and I would have it back to where it is now in 15 minutes, I promise you that.

If and when I ever take the car to a dyno, *maybe* there are gains to be made.

Carbs are not evil. Sure they rough start when cold, but I hope none you go romp on your motors when they're cold.

7300 rpm revving 2.0 SIX on carbs...Out.


KT

Actually the Haltech E11v2 can be set up for full sequential injection, and direct fire ignition. We installed this system on a turbocharged Supercup engine we built. The Bosch Motronic brain was removed and the E11 installed. The installation is really sweet. The original harness for the engine was used, and with the exception of the different color ECU the install looks like it cam from the factory.

The E6X is the unit we sell most of, and yes it is batch fire. On the /6 engine we wire pairs of cylinders together so its really semi-sequential, or semi-batch. ie a pair of injectors is firing when a pair of pistons approach TDC.

Batch fire is fine. making the wiring harnesses is easier, etc..

The 935 clone we built is running E6X batch fired/wasted spark/staged injection, that engine has some get up and go

QUOTE

Very few cars run sequential injection, very little is gained by this. You forgot it’s also batch fired…again very little to be gained.

Every single production car in existence since the mid 90s uses sequential injection, Why because it is the right way to do it. Plus it is cleaner as far as emissions go. When you are tuning a car in location that demands vehicle inspections you have to be able to run it clean. Yes you can do it with batch fired, sometimes.

QUOTE

This is the one I hear all the time....who cares besides techno geeks. Sure it might come in handy on a high-end racecar, BUT a streetcar??? Come on. Just run the damn engine!

I care. I will not risk a 10K-30K$ motor with an EFI system that I can't control every aspect of its operation. Why do you think the factories work so hard on fine tuning the systems in production cars? Because they can't have the liabilty of a car failing an emmisions test, crapping out on the freeway in the middle of rush hour, or puking an engine. I want the same quality of drivability for a customers car as they would have from the factory. That means fine control of fuel and ignition parameters, air temp and water temp corrects, O2 reference, etc. Yes Simple can do some of this.

QUOTE

That’s a broad paintbrush with no substance...please explain the things it ghettos its way through.

For example, it does not offer different maps for a variable cam timing engine. It does a simple switch with no way to control the parameters of the switch or what happens beyond the switch point. Same goes for the Variable intake setup on the Acura engine, the Porsche engines, or BMW engines. You couldn't control the variable intake setup on an SHO engine or traction control system on a Lexus engine. They assume you will just richen up the Fuel tables for anything beyond where that switch is activated. With one of teh systems I am working with you can control the parameters looked at before the switch comes on and the tables referenced by the ECU after the switchover. I can reference MPH, Engine Temp and TPS to alter these points.

QUOTE

In about 10min with no dyno....I counter-point that how can the average person tune with all this clutter (and dyno time). The average person is so over whelmed with information overload that they shy away from PEFI systems. Look at Michel here on this thread, I've told him that the SDS will start right up, within minutes I'll have the A/F dialled in (not that I'll have to tweak it much from the pre-loaded base line), BUT still he wants to break it in with carbs.

The average person doesn't have the understanding of FI operation to tune an engine anyways. Put the average joe on the engine dyno and then the experienced tuner on dyno and see who comes out better. Then send the two out to tune part throttle and watch who comes back with a smooth driving car. Won't be the average Joe.

QUOTE

Again the systems you use are not user friendly. Fast scrolling did take a day or so to learn all the tricks, but once you get the hang of it it's very easy. In a race app I could make a major engine change and be dialled in good enough by about the 3rd corner. Can you say that?

They are user friendly. Most users have no problems using the system. It is not for the average joe, they shouldn't be tuning an engine anyways. Good enough will get you a mid pack finish. I prefer to show up at the track with a fully dyno tuned engine and make a few subtle changes as the weather and track conditions require.

Carbs are fine, they have worked for many years succesfully. They are easy to install and relatively easy to tune. For Michael's situation he will sacrifice some drivabilty for power up high because of the carbs. I don't relish the days of clogged idle jets and having to change my jetting with season changes.

QUOTE

I'm sorry but this is the biggest laugh! How do you save them Money! With dyno time? With a system they don't have a clue how to tune? Please, it makes you money every time they have an issue because they can't figure out (or a just plain too scared to) how to fix it themselves.

Why should the user have to tune it? If the tuner did the job right to start with there should be no user tuning that needs to be done. How many times do you take your factory stock Chevy or Ford back to the dealership to have them retune the FI system? How many of your customers do you want tweaking that 150hp per litre engine? Why would they need to if you did your job?

QUOTE

Doesn't need it. Besides water damage and a couple of the old style coil packs the only failures they've had have been user error. For me 4yrs (2 engines, sold one) and I've never broke down.

Again I guess it is not important because YOU have never had a system fail. Ask EVO owners how it feels to have their AEM system blink out and leave them walking. Bet they wish they had a limp home mode. Can you tune the SDS to handle to handle an overheating condition? What happens if that GM three bar sensor fails? You are left walking with no option, short of calling AAA.

I tune Honda and Acura Engines, Type Fours, VW fours, Turbo VW fours, Some V8s and other engines. With some of the combinations that comes across my counter, I want the maximum control. I can't tell a guy who just sunk 10K into turbo four cylinder that SDS may or may not keep his engine alive. I know Hondata, Motec, Autronic, etc can. I am pretty sure the Haltech system can handle that stuff as well.

For many guys converting from carbs to FI for their older cars it probably is a good way to go, but I won't recommend it to anyone. Just because you have had decent luck with the system doesn't mean it is the best system for everyone. The best system is the one that gets the job done, safely.


In the past I did the basic research into SDS and when I saw that it did not do what I wanted, then went on. There was no reason to do further research.

Michel,

7R case
2.2 rods
2.7 heads
JE custom design pistons
2.2S crank
custom cams
40's
Kerry Hunter headers into megaphones
Crankfire twin-plug
compression 10.5

230hp @ flywheel
185ft/lbs @ 3,500

T.C.

T,

do you have you rport size ?
your jetting ?
When you were Dyno-ing, did you get info on the richness of your mixture (O2 readings)?
Rod bolts?
What do you use as a redline ?

Thanks,

Michel

Yes, that sounds like quite the mill.


KT