I'm headed to M-O this weekend to race. Anybody else going?

I'm trying out a few things and uncovered a problem or two in the process.

For cooling, I'm running 2-3" ducts from the turn signal openings (one on each side)... I know many of you think it's not enough, but I'm willing to try it out before I run a huge duct.

I also replaced by EGT senders with some Westach parts. I was checking to see if they worked and oh, my..... they read a lot higher than my other senders did. I'm guessing the old senders were not the right calibration to work with my Westach gage.

I still have to do the alignment, I'm removing some camber to save weight....

QUOTE (groot @ Aug 19 2005, 09:15 AM)

I'm headed to M-O this weekend to race. Anybody else going?

I wish I was going! I would have liked to score another 6 points (as if I could do that at the Buckeye Sprints ) for a top 3 in my division this season.

QUOTE

I'm removing some camber to save weight....

I did some testing yesterday. With my horizontal cooling system it seems that cyl 2 runs much hotter than the others. My data suggests it is due to airflow under the car and into the engine compartment which alters the pressure differential through the cooling fins, especially at cyl 2. The differential grows with faster speeds. I have an oil filter and oil lines on the #4 side that interferes with the entering air, so cyl 4 doesn't get the same effect.
I plan to do some differential pressure tests with Magnahelic gauges soon, to verify my hypothesis.

I compared head temps with and without full tin surrounding the engine and the temps were slightly cooler without the tin. It may be that the air entering the engine compartment from under the car contributes somewhat to the available air entering the fan inlet.

BTW, I'm really happy with the power from my new engine with heads by Hoffman and assembly/tuning by Raby. I was about the fastest car on the track at NHIS (except maybe the Turner Motorsports BMW world challenge car).
Max rpm I used was about 7800. Kick ass!!

Thanks for the information, Chris.

I'll crawl up in the attic to grab some cooling tin before I leave today.


7800 RPM... I could use some of that. I'm worried about running too much RPM at the end of the straight. (Y 5th gear) I was turning 6000 RPM at the end of the straight at Grattan.

You might try something like the factory air deflectors that went at the bottom of the leading edge of the engine compartment. This would upset the airflow entering the compartment from below and maybe help the pressure differential through the fins.

What do you think is your new rev limit? The Y gear should work ok. Last year I was using an X gear with about 145hp and was still below 7K at the end of the back straight. This year I have a V gear and a lot more rpm.

I know the power drops off at 6000 RPM... but if I can run a bit more timing, I can stretch that a bit. But, I need to get the CHTs down to do that.

Brett donated the valve springs, so I'm not really sure what the rev limit is.

Based on your testing info, I was thinking the same thing about the deflector on the bottom front of the engine. Good info!!!

I've been thinking about this as well, and think it is very interestign the factory choose to install some air deflectors at the very back edge of the pan. This would either turbulate the flow (which is what I expect) or create a low pressure area behind them at higher speeds. The most telling information is the position of the rubber deflectors. Right in front of the cylinders on both sides. If they were for something else, don't you think they would have put them all the way across ?
This really makes me think they are there to increase the cooling ability.

As for the 2 3 inch ducts Kevin, I think that any fresh air you can point at the fan will make a difference. Certainly what may be more important is the duct leading into the hoses. Anything that will create a convergence will increase the eff. of the hose. (Bernouli)

What you have is what I have been thinking about running this year. But our motors are different. Do you have all of your cooling fins in your fan??? If so, i have been told the standard fan will cavitate, but I don't know the RPM. Maybe this is a factor??? Good luck this weekend, Remember, your chasing points.


Erik Madsen

Stock valve springs were good for 6100rpm. The HD springs like Web Cam sells can take over 7000 with the right setup. Do you know what your spring (seat or nose) pressures are or how close to coil bind they are at full lift?
Are you still running stock valves, or SS? Stock lifters or lightweight? Do you have a rev limiter? If so I might try 6500 to start with.

Good points, Erik.

I used some NACA ducts, shaved down for a tight fit, in the turn signal openings. Then I put some metal screen over it. It's actually came out pretty sweet.

I've thought about those plastic deflectors, too. They could have been for gravel protection (you should see some of the crazy things Ford puts on vehicles for gravel protection), but more likely they're for airflow control.

I have 2 fans, 1 stock and another with 1/2 of the blades cut out. At a practice day last week, I started with the partial fan and the CHTs were out of control. I bought myself a few more hot laps by going back to the stock fan. I may try both this weekend. I spend most of my time between 4800 RPM and 5800 RPM and so far, I think I'm better off with the stock fan.

QUOTE (Racer Chris @ Aug 19 2005, 06:56 AM)

Stock valve springs were good for 6100rpm. The HD springs like Web Cam sells can take over 7000 with the right setup. Do you know what your spring (seat or nose) pressures are or how close to coil bind they are at full lift? Are you still running stock valves, or SS? Stock lifters or lightweight? Do you have a rev limiter? If so I might try 6500 to start with.

Chris,

Stock valves, stock rockers, different springs/keepers, Jake's chromoly pushrods and his metal lifters. No rev limiter, just a 009 and Bosch blue coil. I don't know the pressures, but I've got room before coil bind and good clearance to the piston.

6500.... no power there, but if I can turn it that high, then I don't have to worry about my gearing. Cool....

If you run into valve float you can shim the springs to raise the limit.
To get more power at high rpm you probably need head port work, smaller stem valves and additional carb prep.

Good luck! Let us know how you make out. Also let me know what happens in the FP race.

Kevin, the valves springs should be safe to 6500 for sure and maybe 7000. I would test though. If you float the valves once it won't be that big of an issue as long as you don't keep doing it. What valve lash are you running? The retainers are lighter than stock. How much lift does the cam have?

One thing I forgot about, when I put that fan with 1/2 the blades on the car ran hotter, but I had also taken off the goofy plastic things under the car. I made some custom ones that were twice as wide and twice as tall. I also changed the angle to a steeper one. It made a huge difference.

Brett,

Thanks for posting that information. I thought it would make a difference. Good to know someone has tested them.

BOYS,

Put em on!


Erik Madsen

Kevin would you please get rid of that damn 009. Find a 205A from 1.8. That is the dizzy you need.

Yeah get a mallory you cheap prick. LOL Madsen

Sons' o' bi@#%$es......

I know, I know.......I'm cheap, but Jake and I are putting a Electromotive on the new engine.

Okay, so I'm back from M-O. Here's the report... some of which is/will be on the prod site.

Sat practice... I ran two 3" ducts from the turn signal openings to the front of the engine... ran on old tires and managed a 1:47.1 (my best time yet at M-O). CHTs stayed below 400 degrees (but crept up with really hard running) and the oil climbed to 250 degrees by the 10th lap. (BTW... I measure my oil temp just as it goes to the filter and cooler... the hottest location I could get to) I looked at the times other 6 EP drivers were running and realized that I'm not in the hunt for anything but scraps this weekend. Loshak and Schmitt both ran a 1:38 something. EGTs are a little high on #2 and #3, so I went up another jet size on those cylinders.

Sat qualifying.... the skies opened up just before our session. Knowing I wasn't in the hunt I opted to go out on dry tires and live with the results... the rain was stopping and I was hoping... It never got dry enough to do anything on slicks. I was the slowest guy who got a time. For some strange reason my oil temp skyrocketed during the session and I only ran one timed lap. EGT a little high on #1, so I bumped that jet.

I added a deflector between the firewall and the fan housing under the middle of the car... based on Chris's information.

Sunday race.... weather's perfect, low 80s, slight breeze and a few clouds. I starting 21st of 25... some other's never got a timed session. Steve Sargis was just behind me... he lost a wheel during the qualifying session and didn't get a time. I used my new tires My car was running well and I got to pass some guys in other classes as I worked my way around. CHTs stayed around 375-390 and I ran very hard. Oil temps crept up to 250. I managed several high 1:44s in the process. Still not competitive for EP, but getting closer. I finished 7th in class, but moved my way up to 15th overall.

Awesome Job,


Points and your best lap times yet. This should qualify you for the Runoffs yes???

Good to know the shroud deflector helped. Howabout a photo so we can share in the information. See you at the Runoffs you dog.

Erik Madsen

I'm pretty sure I locked up 9th place in CENDIV... through persistance more than speed, but it counts, too.

Now, I just hope not to embarass myself at the RUNOFFS.

The deflector may not exactly be worthy of a pic, but I'll shoot a few whenever I get around to taking the car off the trailer. I just used a 6" piece of alum flashing and pop riveted it to the body. The 3" ducts came out pretty nice, though.

I just spent some time going through the data and realized some things. I left some real speed out there. I know I could have run a 1:43 with this setup.

QUOTE (groot @ Aug 21 2005, 04:49 PM)

I added a deflector between the firewall and the fan housing under the middle of the car... based on Chris's information.

Good deal Kevin!

BTW, my suggestion was to put deflectors on either side, not in the middle. It looks like you had pretty good temp control though.
I think 250 oil before the cooler is fine. I measure my oil temp in the dry sump tank after the coolers and I don't mind if it goes up to 220.

Your times may come down another second or two at the Runoffs since the chicane isn't used.

Actually running a deflector in the middle may work well if you make some other deflectors to speed up the air on either side of the main deflector.

Cool, thanks for the input. I'll try that, too.

Brett, you're right about the springs. I was running the engine to 6400 RPM regularly. Thanks, again!!!

Now, I don't know why, but #1 stopped firing as I took the checker... need to get into that.

Oh, yeah, another interesting bit of information from my data......... I max out at 116 on the straight, which might explain a good portion of the gap between me and the leaders. Last year at the Runoffs, the faster guys were seeing 130-135 mph at the end of the straight.

QUOTE

Now, I don't know why, but #1 stopped firing as I took the checker... need to get into that.

Probably that selective firing issue with the 009.