Test Results - 66200i6 (Dyno)

66200i6

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So...here's the spec's

200 Cubic Inch with New Aluminum Head & matching intake:
no port matching or chamber work and measured chamber volume of 55-56cc (+/-.5cc). Bored thirty over and honed w/Honing Plate.
Dished pistons with an appox. Compression Ratio of 9.5 to 9.8:1 (still need to do static pressure test)

Carb: Off the shelf Holley 4160 390cfm (main jets #65) mounted perpendicular to the crank.

Tires: 195/75/14 @ 25.98" Dia.

T-5 and 8" Diff w/2.79 gears (way too tall).

Curb Weight 2900# w/driver and full tank (weighed at truck scales 5/17/0:cool:.

Cam Grind: H-264-12-B

Cam timing per Waterhouse Motors @105*.

DizzyII timing: 12* initial, 17* Mechanical starting at 1250, all in by 2700 rpm, 14* Vac. Adv. (manifold). Total 43*.

So, at the wheels I'm getting 166 Ft-Lbs torque and 144 HP. The Air Fuel Ratio (AFR) min 12.0, Max 13.6, Avg 12.6 (Holley 390 out of the box).

The first pull was in forth gear. With the tall gears (2.7:cool: it was taking forever to get to 4500 rpm. John finally stop the pull to change the programing. In forth gear the Dyno speed was over 120 mph and climbing. John finished the pulls in third gear. At rpm for the other pulls we were still doing 90+ mph.

The torque curve was very flat and didn't start to fall off until ~4900 rpm. The HP started to level off at about 5100. We tried lowering the initial timing to 10* with slightly lower resulting output. We then tried increasing the timing slightly to ~15* initial with about the same result from the first pull.

The only change made was to increase the initial timing to 14*. So after three pulls and the initial timing change, we were done.

My numbers are lower than some of the other tests but I am very happy. The important factors for me are good low and mid range torque, compression low enough I can turbo if I wish and the possibility of running on regular fuel. Based on the torque curve it looks like 3.50 gears are about what I need to run 70 - 75 mph at a lower rpm. I'll have to work the math out later. The only problem I see going to 3.50 gears is keeping the tires from spinning. I will probably have to invest in a nice set of wheels and tires at that time as well. I think I'll wait until the rubber is used up on the current tires though. Shouldn't take long...

John provided me with a csv file so I will be converting to Excel and plotting. I will have that to post soon.

See Ya'll on the Highway, Ric.
 

82F100

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Ric, 120MPH :shock: :shock: on the open road you'd have a bunch of v-8 guys frustrated cause they couldn't shake a lil' ol' 6 banger :D
Thanks for the numbers
 

MustangSix

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The AFR ratios look a little fat. A slightly leaner setup might pickup some power.

Otherwise it looks good! Way to go!
 

66200i6

Famous Member
Thanks, guys. John had mentioned the same point about the AFR, Jack. I thought I would run a while at this point until I had a few miles on the engine. I would rather be slightly on the rich side of the best setting. I'm almost to the 500 mile mark so I will tinker later.

Also, I forgot to mention that these numbers are with the 10"x2" K&N filter on the carb. I don't know if that would make a difference but I wanted to know what the numbers would be when I am on the road.

Ric.
 

Bort62

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Ric,

Also of note is that you are only running 29* total timing. My gut says that is pretty low, and you may be leaving a good amount of power on the table.
 

MustangSix

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Holleys are always a little fat out of the box. I suppose its to make sure nobody kills an engine or has severe driveability issues. An engine will run fine if a little too rich but not as well if a little too lean.

And I know most think 390cfm is big enough for a 200, but I still contend that with a good VE ratio, you could go a lot bigger. A 500-600 CFM vac secondary 4bbl would probably work well, even on an engine that small. My theory is that even though you have only six cylinders, every intake event on a 200 is over 33ci.

Not sure if you measured it, but at WOT and max power, what was the manifold vacuum reading?
 

66200i6

Famous Member
Bort, at Hwy speed I should be seeing 45 total. The one thing we changed was the initial timing to 14*. That would drop of coarse when I stab it so I guess I could look into the total mechanical advance setting. I’m still waiting to hear from mrarley on his specs so we have a more realistic comparison.

Jack, we didn't measure the manifold pressure during the pulls.

I'm sure the logic behind your thoughts on why the larger CFM carbs would work well or make more HP would make a good topic. Even with each event at 35ci you’re just over 200 CFM. The only drawback with the larger CFM for this small of engine is the need to re-jet accurately. There are fewer guys that understand this than there are not. I was shooting for a simple setup/configuration that could be considered "Off The Shelf". I was hoping Mike could use this as a baseline that anyone could purchase, bolt together and drive.

Ric.
 
A

Anonymous

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Ric,

Nice numbers for right out of the box! ;)

Thats a vacuum secondary carb right? Are you still running the stock secondary spring? I picked up 3 mph and 1/2 second in the qtr mile by just changing secondary springs.

I dont know how much hp that tranlates to though.... :unsure:

And I know most think 390cfm is big enough for a 200, but I still contend that with a good VE ratio, you could go a lot bigger. A 500-600 CFM vac secondary 4bbl would probably work well, even on an engine that small. My theory is that even though you have only six cylinders, every intake event on a 200 is over 33ci.

Thats exactly why I took Jacks advice last winter and bought a 600 Holley, but then my use of the car is totally differant than what yours is! ;) :LOL: :LOL:


Later,

Doug
 

66200i6

Famous Member
Doug, yes the 4160 is a vacuum secondary. I haven't touched it, yet. I have some work to do as far as the kind of vacuum readings I get throughout the rpm range. I still want to do a pressure test as well to confirm my compression.

My driving will mostly be between 2nd and 4th gears. With the torque and rpm range of this cam I am looking forward to enjoying the foothills of the Cascades and Olympics this summer. I still have some work on the suspension to do though before that happens. Right now with the original suspension and stock rims and rubber I'm asking for trouble. In the mean time we'll enjoy some cruising close by.

Gene, I have three 4100's on the shelf. One of them is the polished body that was offered back in the 60's, a 1.08 venturi C5ZF F. I plan on rebuilding that one and trying it later maybe. Unfortunately I will have to rotate it parallel to the crank and rework the throttle setup. So it may be much later.

After watching the Dyno video of mraleys I'm sure I need the same blower hat setup Billr is running. Low profile and 0 restriction. That little 10" dia filter may be a restriction.

Ric.
 

66200i6

Famous Member
Gene, I just re-read your post again. I thought the car that was Dyno-ed with the Pony carbs was mraley's. Have I been asking the wrong guy for timing specs?

Ric.
 

Bort62

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66200i6":2ed0uvj3 said:
Gene, I just re-read your post again. I thought the car that was Dyno-ed with the Pony carbs was mraley's. Have I been asking the wrong guy for timing specs?

Ric.

I believe Mraley's name is also Mike.

Ric, my point about advance pertained to WOT, as vacuum advance will be 0 at wide open. 29 (12 + 17) seems a little low to me, and you may have significan't power left just a twist of the distributor away.

It will be good to see what Mraley's total was during the infamous Pony test. I'm trying to wrangle it out of him on the main forum ;)
 

66200i6

Famous Member
Oh?

Yes I have been asking about the entire setup. The info is invaluable when trying to compare performance numbers from one build to another.

The initial is now at about 14* with the 17* Mech. But it sounds like you think 31* is still too low. During the runs we tried lower than 12* and higher up to about 15* initial. We got lower performance numbers so we dropped it to 14* or 31* "all in". It will be interesting to see the entire range while I'm running. I have a new Stewart Warner tach that works and looks great. I think it is time to get the matching vacuum gage and start taking some data.

Ric.
 

wsa111

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Lets get back to business.

Jack, i agree with you on mixture, drop 2 jet sizes.
Doug, made a proven suggestion & that would be to get the vacuum spring kit from holley & install the lightest spring in the kit.
Ian, yes you are right on the advance. Put 22-24 degrees mechanical advance with 14 initial which will give you 36-38 degrees total.
If you have too much vacuum advance call performance distributors & they will sell you a can with less advance if necessary.

Give it a try and you will definately pick up some lost power. Bill
 

Bort62

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66200i6":33rbsee7 said:
Oh?


The initial is now at about 14* with the 17* Mech. But it sounds like you think 31* is still too low.
Ric.

That's the thing, we really just don't know yet.

Different style combustion chambers will tolerate different amounts of spark advance, and no one has really figured out what is "best" with the AL head. It sounds like you were feeling around and I can see why you set it where you did, but that does seem kinda low. Like Bill has stated, I would sort of expect max power to be found @ 36-38 total advance.

It could be a combination of the overly rich mixture as well as the retarded timing. Tuning can be a little tricky...
 

Bort62

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Also, I wouldn't be too worried about the tires spinning.

As much as we love these engines, they aren't exactly tire burners, regardless of gear choice.

Yes, you can smoke em up if you want to, but I don't think there is a single member here who's car has sufficiently high off idle power to make it difficult to not spin the tires.

That is more of a positive displacement supercharger kinda thing anyway.
 

wsa111

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Ric, i forgot you have the duraspark.

After you get the mechanical advance correct there are a couple of vacuum advance units available.

Borg warner has the short advance V398 & there long advance slot is V397.

I use the short V398 on my duraspark & set the vacuum settings at 4" starting to advance & full advance by 13". Works great. All you need is a allen wrench & a vacuum pump.

I will test my V398 for actual degrees when i get a chance. Bill
 
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