572 all aluminum headed to dyno

572 Indy block with Indy heads headed to the dyno. Best Machine built the long block, we added the Wilson EFI intake and the billet dry sump pan. Should have it on the dyno next week and then it goes into a '67 Belvedere for some drag racing come spring.

Heads...-1's or 573-13?

572-13 heads

The ends of the heads are machined flat.
The EZ heads are done that way.

I like these dyno posts.
Looking forward to more details on the engine. To put the dyno numbers in context.

Interested in the dry sump setup, any lifter valley scavenging?

Correct, Big EZ heads, 325 cc. Compression is 14.5, cam is 280/296 at 050. We'll run it with 2 inch dyno headers. Throttle body is a Holley 2000 cfm with a 4500 bolt pattern. Intake is a Super Victor fully ported by Wilson. T&D rocker arms, Callies crank, Callies rods, Jesel belt drive.

Sounds like a powerful combo. I would love to see back to back numbers with larger headers more suited to 572 CID. How long are the dyno headers?

Is it too early for me to guess 920 HP? But the small headers may reduce peak HP.
From Indy web site for the Big EZ: CNC porting 325cc runners, 370 CFM at 0.700"

2 inch is the biggest Mopar header we have in the dyno room. The headers that fit the chassis are bigger, I think they are 2.25 but they don't fit the dyno. The dyno session is mostly used for confirming the engine is good to go as well as dialing in the EFI tune.

I'm not sure on hp so it will be interesting. I pushed my old 514 with EZ heads up past 900 hp a few times and it had some of the same parts. We used the 2 inch dyno headers for those pulls as well as the same intake and throttle body combo. My heads were a little big smaller than these heads and of course I was giving up almost 60 inches to this combo. The 280/296 camshaft is way different than anything I ran. Most of my testing was with a single pattern cam or a very small split of 4 degrees. I never ran anything with 16 degrees split like this one has. I expect this engine to make more than 900 hp but who knows, the cam and the headers might not get along well enough for that to happen.

It’ll be interesting to see how that cam works at the top end of the curve.

.
I bet it will nose over about 6800 rpm? May end up at 880 hp? But make great torque from 5000 up.

Yeah I have no idea. 16 degrees of split is outside of my working knowledge. I ran a 280/286 in my 514 as well as a 282/288. Both of those cams worked pretty well in that engine. This is a small exhaust port so the extra duration might be what it needs. I might have been leaving power on the table with one six degrees of split. We should have numbers in a week so we'll see what they show.

Do you expect the large duration split to improve or reduce top RPM power?
I do wonder if the "small" 2-inch dyno headers (which may be longer than 30"?) will reduce the top RPM power.

I don’t know that I have an “expectation” on what it will do.
This motor has slightly bigger heads than a 580 we had on the dyno a couple years ago.
It also should have better oil/windage control, a better intake manifold, and more throttle body capacity.
The one here had a couple more degrees of intake duration, but less split.
It didn’t make anywhere near 900hp, but we weren’t expecting it to either.
Peaked at 64-6600, and didn’t really drop off till 7k(down 20hp).

I’m interested to see where the TQ peak occurs, and then how flat the HP curve is at the top end of the pull.
Basically....... can the big split help cover up for the smallish intake/exhaust ports for that displacement?

If it had “big” heads, I’m sure that trend of the extended top end would be there....... but not sure what to expect with the smaller heads.

When the induction isn’t the cork in terms of where the peaks should occur, the big split can really help move the peaks nicely up in the rpm band.

2" Headers are going to hurt HP on the dyno - we have seen more than 30+ HP loss with the smaller headers going from a 2 1/4" to a 2" to 2 1/8" stepped TTI header - I can also tell you from experience those heads did not work well for us with that cam spec on the exhaust side. Should be interesting to see what it makes - Are you going to run a vacuum pump ??

It has a dry sump oil system now

Loaded up and ready to go.

Who specc’ed the cam?

Can you give the complete cam specs ? Maybe show the cam card . Gary

If Best Machine built it I'm betting they came up with the cam grind.

Looking forward to the results.

Any more pictures/details on the oiling system?

Awesome engine!

If Best Machine built it I'm betting they came up with the cam grind. [/quote
I have had them do a motor and had the cam for it elsewhere... which I why I ask
In my case I took Dwaynes recommendation

Nothing special in the oiling system, mostly off the shelf parts. Aviaid billet pan and a Peterson R4 pump. Here is a link to the pan: https://www.aviaid.com/shopsite_sc/store/html/mopar-oilpans.htm

Did the heads get 2.25” intake valves installed?

Yes, heads were reworked to match this shortblock. Chambers opened up for the 4.50 bore size, 2.25 valves, etc.

It seems like a small head for what otherwise seems a pretty aggressive setup, any reason why? S/F....Ken M

It is what the customer wanted to do. It makes sense based on the customer's plan for his car.

I've not seen a duration split like that on a Big block, it's pretty common on high HP small blocks though.

Will be interesting to see the results

Some LS engines come from the factory with 20 degrees more exhaust duration. I don't know why they do that but they do. I think the LS7 engine has about 20 degrees more duration on the exhaust than on the intake and that is a production engine right off the showroom floor.

When is dyno day?

I have run exhaust splits that far many times on a BB. We have run as much as 16 degrees more on the exhaust side. Be screwing a new Predator together here soon and based on past experience it will have at least a 10 degree split(cam is the only thing we have not decided on yet). Expecting to to make 1130-40 with a very bracket friendly single 4 combo for stop racing.

Any other guesses?
For the record, using those small headers I am subtracting 30hp. 890 HP with the peak below 7,000 rpm.

I'll guess 904hp. Peak around 6700.

Indys suggestion to me for a 572-13 head on 550 cubes was 285/305/112 in at 108. Considering those heads come with a 1.88 exhaust valve, i was surprised . They also said max lift of . 825. I will make due with my 284/296/114 with . 868 gross intake lift. Considering lash etc i will be below . 848 net lift intake.

Sounds like a beast.

PipeMax says 904 hp too.

We made a few pulls today. It made 870 power at 6800 and 760 torque at 5400. Found a few items to work on. Not sure if we'll put it back on the dyno or just make the changes and put it in the car. Depends on what the owner wants to do. No doubt in my mind that it would easily make 900 hp with some minor changes.

Used the clear valve cover to verify top end oiling. Everything looked great. This engine uses pushrod oiling with the T&D rocker arms. The engine ran great, no leaks and only a tiny bit of aluminum trash in the pre-filter. We cleaned the filter after each dyno pull and by the third pull the filter was spotless.

very nice

Short video of the rocker arm oiling. This is at a fast idle. Quite a bit of oil gets slung around even at 1500 rpm. At higher speeds the window is covered in oil and you can't see anything.
https://www.youtube.com/watch?v=QXWqTQBE-no

Just putting larger dia headers on it should make more peak HP. About how long are those 2" dyno headers? maybe 34" ???

I don't have a good feel for the torque peak RPM, so it is nice to know 5400. I could only guess 5500-5700.
Do you think that is mostly a Super Victor intake function, and a Indy 440-3X would push the peak higher?

Does the Indy block have bronze bushings or a wide open channel to feed oil to the lifters? Any restrictor to the lifter oil passage? What pushrod oiling lifters is the customer using?

Best installed lifter bushings and the engine has Crower lifters. I assume there is a small hole drilled in the bushing but the engine was purchased as a long block so I don't have any pictures of the internals.

I think the 2 inch headers are 32 inches long. I had Stahl build them for me 20+ years ago. I've used them on 900+ hp engines before but the engines were smaller. If I was trying to wring everything out of this 572 then I'd have a larger set of headers built. PipeMax recommends 2.25/2.375 step headers with a 4 inch collector.

Andy, i am surprised pipemax came up with 2 1/4 to 2 3/8 tubes. Pipemax gave me 2 1/8. To 2 1/4 for a 550 cube 1050 hp build. The 550 with 440-1 heads made 926 hp with 2 1/4 dyno headers and only lost 7 or 8 hp using my chassis 2 1/8 headers.

Here is my story on headers, and it has been repeated numerous times. My son had a set of 2 1/4 to 2 3/8" stainless tubes for his dragster with a 4.5" merge collector with a 4" choke, he loves his bling so even though I told him they were to big he wanted stanless. I have told home for a year they are to big. Finally after a year and change he put the 21/8" to 2 1/4" with a 4" merge 3.5" choke on the dragster. It instantly picked up 6 hundredths and with jetting ended up .08 faster than the larger header. Also picked up 3 mph. Car has been mid 4.53 at 153 with the smaller header, I'll let you all decide what it makes for power but it weighs 1920 and these runs were of course in Vegas. Best ever with the big headers was 4.61 150. Needless to say he is now building a new stainless set to match the smaller header. From my experience most Mopar guys seem to LOVE headers that are to big! My Stratus had headers that started at 2 1/8" to 2 1/4" to 2 3/8"had a 4 1/2" merge with a 4" choke(too big) and it was 1200hp

Andy, how high did you take it, and what was the power at the end of the pull?

DONT want to Hi Jak this....but ive been told my 2 1/8 to 2/1/4 headers were too small, and way too long at 32 to some 40" tubes. Now im told to build a set . the "new" headers are going to be 2 1/4 to 2 3/8 and with a 4.5 collector....and no longer than 26"
AL you know what im building now. My current 530" i was told i was leaving at least 30hp or more on the table between the headers and the B1 intake/spacers.

We pulled 4500 to 7000 rpm. The power curve was still flat at the end of the pull. The power numbers on this pull starting at 6500 rpm are 855,854,859,861,856 and then 860 at 7000. So dead flat for the last 500 rpm. Should pull down the track pretty well in high gear.

In the case of a nitrous or blower deal I believe bigger is better. FWIW it of course is all combo dependent for sure but in your case I would likely look at the larger tubing size. Also high RPM stuff seems to like a bit more header provided its not a very small cube deal. We went from an 1 7/8" to 2" header on the Vette a few years ago to a 2 1/8 2 /14 2 3/8" deal on the Vette and found 28HP. In that world thats huge but we knew we had grown well past the small tubes. We have pipemax as well, but couple that with our experiences to make a final decisionon tubing size. BTW the large tube headers that were on our dragster were from when the engine was a nitrous piece trying to run TD.

The top end of the curve looks good. I’m sure the split is helping with that.

Yeah, that could be the benefit of having so much split. If it was my engine I'd try a cam in there that I think would be good and then I'd know. I have a feeling that the cam specs I think are good might not make as much power as the cam that is in there. But that is how you learn.
I'm converting it over to a crank trigger now since the distributor had some spark scatter. The owner is waiting for a new Reid case Powerglide so no rush on getting the engine into the car. While I have it in my shop I'm going to tidy up a couple of things. I never liked the way the dry sump pump was mounted so I'll build a new bracket for it and clean up some of the plumbing.

I'm surprised that those heads can make 900HP but then...I've never seen them. What do you feel needed changed to realize 900HP? Either way sounds like a good engine.

My 514 engine had EZ heads on it and it made over 900 hp several times. Here is a super long thread on that engine if you want to look it up: https://board.moparts.org/ubbthreads/ubbthreads.php/topics/804381/14.html
Chuck said I should've tried more ignition timing so that is one thing. I also had the AFR at 12.8 which is safe. We could've leaned it out a bit. We were using C12 which is a decent fuel but there are other fuels which can pick up power. Bigger headers would probably make more power. PipeMax says the valve lift need to be higher. Right now the intake is choked because of the low lift. We didn't want to go with Jesel rocker arms on these heads so we are limited by the shaft rocker in what you can do. I'm sure there is more power in the valve train but not easy to get to in this configuration. Switching to Jesel rocker arms on my old 514 was key in picking up a bunch of power. Also, if this was my engine I'd switch over to a belt drive distributor. The belt drive distributor is more stable which means you can safely creep up to the limit with the timing.
My 514 started out as a 750 hp engine but after a 100 dyno pulls we had it over 900 hp. Same basic long block combo, just changed the cam a bunch of times, ported the intake, switched to Jesel stuff, etc.

My feeling on the affect of the big split is....... I feel like you’d have to turn the motor even higher to really see the influence of it...... sompared to something similar but with less split.

The thing I’d be curious about in that scenario was whether or not the big split cost any power within the “useable range”...... compared to less split.

That stuff rarely gets tested for typical bracket race combos.
Usually you’re looking for a number, and as long as the results are pretty close....... it’s “good to go”.

With the work done to the heads, they are basically improved 440-1 with the lower EZ exhaust port.
So with 572 CID, 14.5 CR, lots of duration, Wilson intake, I can see the 900HP. Not EZs right from Indy...
My old 540 with 440-1 CNC 345 heads was a copy of a 875HP motor and was only 13 CR.

Dwayne,
Do you think the 5400 rpm torque peak RPM is mostly a Super Victor intake function, and a Indy 440-3X would push the peak higher with 572 CID?

Jim, I have never used a SV for a BBM, so I really can’t answer that.

However, a 572 I built that used 572-13 365 heads and the 3x intake made peak tq at 5600.
That manifold was just port matched to the heads.
Those heads have ports with a larger cross section and bigger valves than some EZ325’s, so I have to believe at least some of the higher peak tq rpm is attributed to that.

That isn't much difference for the big increase in volume. Were the cam specs similar? I'd be disappointed if I told the owner of this engine he could pick up power by switching to 572 heads down the road and then found out that it didn't move the peak much.

I think Greg won the bet. I feel the customer should be happy with that engine. Especially with the larger dia headers in the car.

ANDY/JIM ...I guess I didn't liken this 325 head to a cnc !345! -1 let alone an 'improvement' over that head, which has proven itself to make that power. The 345 is made with the 2.25" intake. The "etc." didn't speak to 20cc TO ME anyway. I was more complimenting/pleasantly surprised than denying the possibility. Also was curious what you thought would improve power.
JIM...I never 'ran' the numbers on your 540 but I know it ran good. What was the mph/weight? If you feel it doesnt take away from this thread can you share the details of that motor? For some reason I thought it used hand-ported -1's. I agree that with a different header there would be more power but, I would think that would necessitate a cam change to fully realize more.

HardcoreB,
The only other significant info on my old (2015) 540 CID was the Best Machine spec cam 279/290 112 LSA and 1.65 T&D paired rockers. About 0.777/0.750 lift. The car ran a Ron's Flying Toilet alcohol injection. I loved that injection.
Nothing fancy.

Correction factor on these pulls was 97% so we were losing 25 hp from the correction factor. Uncorrected numbers were 885 hp. Of course, it would've been tough to hook up at the track on a 50 degree day! I think the baro was 103 kPa so air was good.

The customer wasn’t looking for a high rpm screamer.
He wanted something low maintenance.
I freshened that motor after a few seasons(250 passes), and it was like new inside.

It made peak power at 6800(918hp), and he shifted at about 7k.
Ran a best of 8.33@165 in a 2750lb car.
The 918hp was with an 1150 carb. In the car he ran a 1050 I reworked that was down about 10hp on the dyno.

The cam was 283/292-12.

I'd expect more power from 572-13 heads but I suppose if it had a cast intake and a modest cam lobe then 918 might be where it ends up.

I was pretty happy with it(and so was the customer), and the on track performance spoke for itself.

As always the MPH and Weight ALWAYS tells the true tale. Dynos are a tool not a be all end all. The 8.33 at 2750 is making decent steam sounds like Dwaynes dyno is on the stingy side if anything FWIW

I agree . Pretty good MPH at that weight.
Doug

Andy I don't see a pick up on the crank? was rhe dyno pulls with a dual-sync?

Dyno pulls were with a dual sync. I switched over to a crank trigger after the dyno session. The dual sync didn't provide stable timing so we're changing it before the car goes to the track. I'm also redesigning the oil inlet and pump bracket.

I don't think I'd feel good about recommending 572-13 heads to this customer and then have him only pick up 50 hp. If this customer switches to 572-13 heads down the road then I'd want to see over 1000 hp.

Will you still use the DS or switch to a pro billet? What EFI will he be using?

Thanks, john.

I'll use the DS but only for the cam signal. I'll get the crank signal from the crank trigger using a Holley Hall Effect pickup and a MSD four magnet wheel. I'll keep the 50 degree reference angle from the DS. They have a Holley HP ECU in the car running V5 B170. It is sequential injection using Holley injectors in the manifold runners near the ports.

Got ya.
Any reason for the MSD wheel vs your 36-1?

John.

Respectfuuly, if you can explain how these '900hp' 325cc EZ-1 low -port heads are better than a 345cc -1 then it would be easy to explain how an equally prepped set of 572-13 heads would pick up OVER 50HP. There are a few examples of 572-13 headed motors that make over 1000HP. At least one I know of came from your last engine builder! 8.6's @ 3350 on a 10.5 tire about 15 years ago. Beyond the added flow and cross-section just like you have mentioned the improved valvetrain allows 'more cam'.

It is a BB Chevy front damper pattern so my 36-1 doesn't fit.

8.60 @ 3350 would require a little over 1000 hp depending on how well the car was sorted out. I think the customer would be happy with that. Chuck didn't think 1000 hp was an issue with 572-13 heads, good compression and the right pick of cam, rockers, and exhaust.

The motor I built used the smaller 572-13cnc365 since the plan was to not rev the motor all that high.
On my bench that version of the 572-13 only flows 5-10cfm more than a 440-1cnc345.

I'd rather have a stingy dyno sheet, and a happy time slip, than a happy dyno sheet, and stingy time slip. The 572 Andy built is going to make a great bracket engine for the customer.

Finished up the new dry sump mounting bracket so now the engine is ready to go in the car. I also converted the dual sync distributor wiring over so it will plug into the same harness as the crank trigger. Now the EFI system is getting the crank signal from the crank trigger and the distributor provides the cam signal and distributes the spark. Might eventually upgrade to a belt drive distributor but for this season I think they'll run it like this.

The 572 is in the car and getting ready to go to the track. First track day here is March 26, forecast calls for rain so we'll see if it happens. They were planning to run a PG behind this engine but the Reid case has never shown up so they put the 727 back in the car. Had already built a new crossmember and loop for the PG so all of that stuff had to be cut out and redone. Sucks to be building cars when everything is on backorder.

Ugh! Welded the new stuff and had to cut it out. Pain in the butt.

Worked on getting the idle dialed in today. This engine needed a different fuel map than the old 505 due to the very radical cam. I wasn't able to use the O2 sensor to control the AFR at idle so I had to build a manual fuel map. But it didn't take too long to do and then we a little bit of testing in the driveway. It jumps when you give it the gas!

Finally got it running well enough that it can go to the track. The cam used in this engine was not EFI friendly! I think this was the most work I've ever had to do to get a tune dialed in. It wasn't too hard to find a happy spot for idle, but the off idle area was super difficult to nail down. The engine would die as soon as it went into gear and it wouldn't do anything when the pedal was slowly depressed. Finally figured out that this engine works okay with a lean idle, but it wants a bunch of fuel added as soon as the pedal is moved off idle. Anyway, got the tune wrapped up and then loaded the car onto the trailer so they can take it to the track on the next sunny day.

What does the car weigh race ready?

Ready to run without a driver is 3000 lbs. Not sure on the distribution, I'd have to look up the scale info.

Ran 9.36 @ 143 first pass off the trailer with the new 572. That was with the transbrake at 3000 rpm and shifting at 6300 rpm. Pulled a pretty good wheelie leaving the line which kind of surprised the driver. Going to take a little bit of time to get comfortable with the extra power. I think the car has enough power to go 9 flat at 150 mph but it is going to take some time to sort it all out. Might need to make some changes to the chassis before that happens.

Thats about 772 hp at the engine. going by the wallace calculator.

Using 9.36 at 143 mph:
Wallace at 3000 lbs: HP computed from your vehicle ET is 721. flywheel HP
Wallace at 3200 lbs: HP computed from your vehicle ET is 769. flywheel HP. Adding 200 lbs for driver.


Shifting as early as they did, it should go quicker when they are ready to rev it higher.
Using 9.00 ET:
Wallace at 3200 lbs: HP computed from your vehicle ET is 865. flywheel HP (about what the dyno measured).

Jim, my comment was as it stands 772 hp at 3200 lbs including driver. not what it may do in the future.

Yup.
I was just adding some detail for the reader, showing est driver weight etc.

I tried the Wallace using weight first and then MPH, ET said 747.11 HP, MPH said 809.35 HP

Car ran consistent 9.80's for the past couple of years with a stock block 505 and Trick Flow heads so the owner is happy with the big boost in performance. They are racing today but I'm not at the track. I'll be interested to see where the times end up once the car gets sorted out. I'd be surprised if the car has a high 8 in it, but I'm thinking they'll be able to run low 9's on a regular basis.

The Moroso chart shows a 9.40 for 143mph.

Power to weight of 4.44

Wallace> 765fwhp@3200lbs

60 Foot E.T. : 1.30 Seconds
1/8 Mile E.T. : 5.92 Seconds
1/8 Mile Trap Speed : 114.78 MPH
1/4 Mile E.T. : 9.39 Seconds
1/4 Mile Trap Speed : 143 MPH

865fwhp 3200>
60 Foot E.T. : 1.25 Seconds
1/8 Mile E.T. : 5.68 Seconds
1/8 Mile Trap Speed : 119.58 MPH
1/4 Mile E.T. : 9.01 Seconds
1/4 Mile Trap Speed : 149 MPH

http://www.wallaceracing.com/accel-calc.php
always used this for years, input weight and change hp for ET/mph at sea level numbers.

I downloaded a few data logs today and looked them over. As expected, the stall speed went up with the change from the 505 to the 572. The converter is flashing to 6600 rpm now when the brake is released and then it drops back a hair to 6500 as the car starts to accelerate. The driver shifts 1-2 at 7300 and the rpm drops back to 6600 rpm. Same on 2-3 shift and then the car goes thru the lights at 7000 rpm. Car doesn't have a driveshaft sensor so I can't see slip.

The vitals all look great. AFR is 12.8 all the way down the track, fuel pressure is steady at 60 psi, oil pressure is right at 70 psi, coolant temp is 180 degrees, battery is 13 volts with the alternator charging. Engine is using a little over 400 lbs/hour of fuel as it goes down the track.

I looked at three runs and they all looked exactly the same. He has the 2 step set at 3500 rpm which seems low to me, but it is pulling a two foot wheelie so he doesn't want to go any higher.

Can you give us all the incrementals and respective MPH? That may paint a better picture. Also what is the DA/elevation/weather info? Thanks!

Here is a screen shot of the data log. The white line is 6500 rpm. I showed the data log to the converter mfg and he recommended shifting into 2nd sooner and then winding the motor a little harder in 2nd before shifting into 3rd.

Based on those comments I am gonna guess the converter is made by A1 And yes out of first sooner is generally always a good idea and the faster way down the track.

I was thinking the converter needed to drop back more after shifts but the mfg told me that these days they don't focus much on drop back rpm. He said they have some very fast cars that run with very small drop backs after gear changes. Keeping the engine right at max power all the way down the track is what they are trying to do. So that makes sense, I guess the issue is having the converter slip enough to move the drop back point higher into the power band without having it slip too much. The stall point on the existing converter is only a few hundred RPM less than peak power.

One of THE biggest issues I find when helping folks with their combos is the converter fall back. Most guys think 15-1600 is fine, WRONG! Thats outdated antiquated thinking on the subject. All that is going to do is slow you down. Every combo is different for sure but anything with 4 digits of fallback is going to be to much. In my experience "loose inefficient" converters tend to be fast. If you are looking for an ultimate low ET then thats they way one should lean. Companies have gotten much better at making loose converters more efficient in high gear for sure. We even have a lock up option now. In the heads up car we like to see 5-600 on drop back. But alot of factors play into getting there, weather, gearing, tune up etc.

I've had several 9.5" converters in mine. From 1300 fall back to 600 fall back. The 600 was pretty good. The current one drops about 800-900 depending on shift point rpm. But it is consistently better on R/T than the other two.
Doug

I help tune an 8 second car with a PG. That car only falls back 50 rpm on the 1-2 shift. Kind of crazy and I'm not sure that is the fastest way down the track but that is how it is set up. You can't even really hear the shift and the data log only shows a small blip when it shifts.

I was originally taught that the engine should fall back from peak power to peak torque on the shift which is about 1500 rpm for most engines. But I think that is now considered "old school". It does make more sense to keep the engine right around peak power as much as possible.

My S/P car with a Mikes Monster glide with a 1.80 low gear set drops between 1400 and 1500 RPM depending on the shifting it out of low gear, shifting it at 7000 RPM would drop it back to 5600 RPM, shifting it at 7300 RPM would drop back to 5800 RPM in the 1/4 mile
All the incremental times except the 1/4 MPH were identical, it ran 8.862 ET at 148.? MPH (the last two MPH digits are in the logbook in the trailer) shifting it at 7000 RPM, shifting it at 7300 RPM 45 minutes later in the other lane made it run 8.864 ET at 150.?:? MPH The 60 ft, 330, 660 and 1000 FT times were identical to each other

You would probably go quicker with less RPM drop but it can be a hassle to test converters, especially at the track. Need a couple of strong, limber helpers to dive under the car and change the converter. I'm not interested in doing it at the track anymore that is for sure.

Awe come on we have been known to have the transin and out three times in a day, and trust me in the Vette NOTHING is easy.

IF you have decent data to provide......i have been told you will keep going faster, every time you change the converter

Wish that was true..Being lowly NA racers we have to change stators, or trans gear rations sometimes way to frequently chasing weather conditons. Part of the joy of racing across the country

But we only have 42 data channels we monitor, maybe we dont have the right one

Here is an OLD screen capture from 2016 when we only monitored a few things and were still learning how and what the car wanted. Also way less RPM then. Looks a LOT different these days but dont have a picture of any. Maybe ill take one this weekend and high lite all the channels just for confusion

i really doubt the owner is going to be making a bunch of convertor changes, when he plans on switching to a Glide anyways. The only thing that matters at this point, is the customer happy with the results?

I would agree but always fun to speculate. In a glide the converter is the make or break piece.....Even more so than a three speed.

“Engine RPM” = 9777

That was back when the engine was a "big" smallblock. It was 440" a fair bit smaller now and the RPM is a fair bit higher these days. We now shift 2/3 at 9900ish go through the top end at 10,2-10,400

We have been racing 1/8 mile out west of late. We don't change the car from our NMCA trim for it, we run legal weight and our normal trans ratios, rear gear and converter and go through the 1/8 stripe still on the converter, which stalls at 9200-9300 if we got the stuff right.

Al, looking at your data, is that where you like your A/F at or did you correct it?

First off I really didn't intend to muddle up Anyds thread so bad, so I apologize. Since this is not a Mopar figured no one would care to know.

Every combo is different and every fuel, racefuels vary widely, has a different ideal stoich number(I see racepaks all the time where people don't use the correct stoich for their fuel, lambda really is the better way but I like stoich). Bottom line is we run the car where it is fastest, we don't have a number in mind and shoot for that on the track. We pay attention to the timeslip and when we are happy with what we see there we then will come up with our own target AFR number. Again all combos are different but don't ASSUME stoich is where you get the optimal performance. I know some folks think that number is a be all end all and I'm here to tell you in the heads up world that it just isn't that simple. Dont chase a "magic" number chase the slip......

That screen capture was early on with the smaller engine and we were not 100% on it for sure. Carb was to small(2.300" throttle blade)and we were struggling with the new changes to the manifold, first time we had the BIG intake on the car. Having said that for the fuel we ran back then the car was always happiest at 11.6-7-1 for a target AFR. These days we are at a higher stoich number on the tune, and a different fuel. Its always a balancing act with a single 4 carb and intake to get all 8 holes happy. We are still chasing some distribution" issues" but the car keeps getting faster. Carb is bigger, fuel is different and we run a fair amount more RPM these days. The car just went 4.98 140 last time out so we are getting closer to the fast guys in NMCA NA10.5. We dont make a ton of power we try to be really efficient down low. We have a coupe timeslips that show sub 1.10 60' but we don't 100% believe that number yet, but either way aint bad for a small block at 2770lbs. I don't worry near as much about the "ideal" afr as I do the wheelspeed at .5 into the run If AFR is in the ballpark we are ok, if wheelspeed is not in the target zone we just are not fast.

Just to muddle it up some more here is a screen capture of a run a last year. Driver short shifted(refuses to use an air shifter) but just to get an idea of distribution on all 8

The green line, and red line are supposed to match in high gear. LOL.

They get much closer in a 1/4 mile than the 1/8, maybe even more odd looking for a clutch guy Beenmy experience looser is better in our world...Remember we don't set the car up to run 1/8. However you do know with a lock up that green line actually goes above that red one right

I did not know that. Interesting.

Belvedere was back at the track today making passes. First pass he hooked up and the car went way up into the air. Scared the driver a bit since the car had never gone that high. Front was probably 4 or 5 feet in the air. Next pass he lowered the two step too much and the car bogged off the line. So it is a work in progress.

Only made two passes?

They were still racing when I left. Even with the bog off the line he ran a 9.30 so once he gets the launch sorted out he should pick up some.

Looks like the car would benefit from an anti roll bar.

Yeah they were talking about that. I think they are going to put wheelie bars on it and add a rear anti-roll bar.

Definitely NEEDS an anti roll. Lots of ways t tune a wheelie out and if only using them as a "safety" device will be just bad as tuning the wheelie out on performance.

Ran a 9.27 today without any changes to the engine.

Getting there Andy. 794 hp what was the best mph?

145 mph. Wallace says 850 hp, Moroso slide rule says 810 hp. I don't think the calculators are correct yet since the car isn't dialed in. The driver is still working on the best launch RPM as well as shift points. The chassis hasn't been fully sorted out either.

I thought the race weight was in the 3200lb range??

I posted that the car weighs 3000 lbs

So, 3000+ driver.

I guesstimated 3200........ I suppose that could also be 3300, or more.

Yep, driver is a very big guy.

The Big EZ heads made it two seasons before they developed leaks in multiple intake ports. So we're looking at different options. Looks like the best bet is to step up to a set of 440-1 castings with the 345cc porting package. We'll have the heads cut to the same 74 cc combustion chamber so the CR stays the same. Hopefully valve to piston stays the same but that will need to be checked. Hopefully the valves, springs, rocker arms, etc. all swap over from the Big EZ heads to the -1 heads. As far as I can tell everything will swap over, but I could be overlooking something.

I was of the assumption that the intake port of the EZ was the same as the -1. The difference between the two being the exhaust port height. I have to say I wouldn't be happy with multiple intake port leaks after 2 years of use.
Doug

Oooof! that's not right. Hope there is some restitution for you. Do they leak OIL or COOLANT? What MPH/ET did the car wind-up running? Probably not great MPH because it's not the most aerodynamic set-up.

The cnc345 is really better with a 2.25” intake valve.

Were those used in the EZ heads?

As cast, the EZ head has its own unique port shapes not shared with the other models. The floor is higher than a -1, with a much more rounded approach to the SSR, and a larger SSR radius.

I do believe the ez325 and the -1 325 utilize the same cnc program in the intake ports(I’m not certain of this since I haven’t had a pair of each here in the shop at the same time), which removes quite a bit of material from the EZ floor.

Agreed...the -1 345 SHOULD have the 2.25" And IIRC AndyF said his had the 2.25 installed by BEST. Wonder if they use the 'SR' INTAKE port with a lower exhaust? Randy has the cnc '345' -1 Indys with 2.25" Intakes on his jalopy with a SMALL/gentle cam you spec'd. 540" 12.9:1 It showed about 146 or so MPH so far @ 3300lbs. But there's definitely room for more in it's performance.

Hey Sean,
Looks like I quoted the wrong post

The Big EZ comes with a 2.19 intake but Best Machine opened the heads up to 2.250. So we'll be able to swap the 2.250 intakes over to the -1 heads. We kind of have to go this way anyway since the Big EZ castings are not available at the moment. The other choice was to step up to the 572-13 heads but that was going to be a bunch more money and time to replace pistons as well as other parts.

The car was pretty consistent in the low 9's the last time I saw it. I don't think I saw the car run at all in 2023. They toured around to some different tracks but I never happened to be at the same spot.

Heads are leaking coolant in multiple ports. I've heard that it can be a problem with the Big EZ heads, especially when they are opened up for a larger intake valve. We rolled the dice on this engine and lost. I have a lot of confidence in the -1 345 package. I've seen a lot of those heads in use and haven't heard of any issues with them.

It might be worth sending the heads to Indy to see if they can be repaired.

Do you know what areas of the port are leaking?

I know a guy with both 440-1's and 572-13's that would consider selling one or the other. Same guy is modeling some 1.3 ish C/H 572-13 pistons around a 4.505 bore.

I talked to Indy about that and they said it is a known problem and that they can repair the heads. The leaks are all in the same area on each intake runner. In the bowl area above the valve seat near the short turn. You have to rotate the head at just the right angle to see the crack.

The engine builder said he doesn't want to put heads with multiple repairs back on the car so he voted for new castings.

I figured that’s where they would be leaking from.
A lot of material gets removed from there with the 325 program.

The EZ intake ports are not the same as the SR either.
In ootb form, they’re better……..and easier to get into the 340+ range.

Hard to believe I sold that cam to your friend 15 years ago!!

The cost to go with 572-13 is high, since you have to change rocket gear, pushrods, pistons. But power at that level is never cheap. Top it off with a recert on my car, since i am certain it can now run sub 8:50 and exceeds 150 mph, needing a head restraint system this year. In my case, going from a 550 cube 15/1 compression combo with maxed out 440-1 heads sporting 2.30/1.78 valves, dyno numbers were 926 hp. A move to 572-13 cnc385 heads, same size at 549, but an aluminum block, yielded 982 hp at a higher 7600 rpm . Now if i build a bigger shortblock,,,,,,,,,,,,,,,,,

Right! He's really happy with it. At the rebuild, he considered more power so, I loaned him a bigger one to test fit but it didn't have the P2V to use. I more showed the specs to give a performance context to this thread.