How about your best guess-RPM

[gregaba]

Running a 428 blueprinted block. 427 4 bolt mains, Racetec forged pistons, 11.4-1 compression ratio, bore 4.164-deck 10.155
I am going to run the D cam for now but will probably swap it out in a few months.
Harland Sharp roller rockers,TFS power port heads-no mods-, FE Power timing set and cover with FE power intake adapter, TFS single plane intake 4V with Holly Sniper EFI with a future switch to Megasquirt EFI, Hooker super comp headers or Mad dog's.
 will be using the 6R80 behind it with a 3.73- 4.33 rear gear.
I would like to know about what RPM's people have safely run similar  combo's at launch and shift points.
I know there are a lot of factors that will make this only a guess but i would like to see what everyone thinks is reasonable.
Thanks
Greg
Thanks
Greg
 

[Joe-JDC]

I raced my 452 FE for several years with D camshaft, MR heads, TW, C-6/trans-brake at 4500 rpm, and shifted 1-2 at 7000, 2-3 7000 rpm, and went through the lights at 7400 rpm to 10.94 @ 123.65 mph on regular basis.  '69 Mach I with 4.57:1 gears, 10.5 x 15" tires. Mechanical tach drive tachometer.   Joe-JDC

[gregaba]

Nice running 69. I would be thrilled with 11 second time.
Engine is going in a 63 Galaxie 2 door sedan. Car came from the factory without heater Etc. but is not a light weight. Has had the rear modifier with 8 inches shorter wheel base. The rear has been narrowed buy the original owner and I can get 13 inch tires in the rear.
I pulled the roll bar out but left some of the other mods on the car.
It is just going to be a fun car for cruise nights and some trips to the drag strip.
I did add a radio because I am a whimp.
Greg

[Falcon67]

You didn't say what rods are in the motor and what your expected converter flash stall may be.  Good rods should not have an issue with any street/strip RPMs (6800~7200 or so).  A tighter street style converter will be the real limiter in your combo.  You'll not be able to get much past 2000 staging RPM holding with the footbrake and it will also limit the rate of acceleration.  You'll also likely end up "short shifting" because buzzing it up won't make it any quicker, so 6500~6800 would be my guess for best overall ET/MPH.  If you run a loose converter that flashes to 4000+, then maybe more RPM.  Loose converters generate heat during cruise, so there's that. 

[gregaba]

I have a new set of the Scat h beam forged rods stock size.
As to the converter as of now I will be running the stock 6R80 converter but am considering an aftermarket but they are $1200.00. For what I am using the car for I am not sure If I will need it.
One thing about the 6R80 is the factory built in trans brake which will help on launch.
I am not a trans expert so any advice is welcome.
The car will be mostly a cruiser fun car with may be 8 to 10 trips to the strip a year.
Greg

[My427stang]

The issue here is you are asking two questions and one is harder to answer

1 - Safe RPM - I'd say your parts, if machined and assembled well would be good to 7000, maybe 7200 shift point, but if it's a factory 428 crank, they can be fickle.  Balancing matters and recommend a close runout and mag check, magging not only on the crank but also #2 and #4 mains at the threads and in all saddles if it wasn't done during the conversion to cross bolts.  I will also add that those are heavy parts, so I would likely balance every part you can bolt on to the crank.

2 - Peak power RPM - The D cam is an unknown with TFS heads, from the original banter, I was not a fan, but that's not what I mean.  A 335 cfm, relatively small port head, with a good chamber is what guys dreamed about but did not have when that cam came out, same with the good intake.  In fact, I am not sure we have seen much modern cam testing on big, tight LSA cams with the TFS heads yet.  I really would recommend some dyno tuning before it goes in and make some decisions from there on gear and converter choice.  The TFS top end will make power, probably lots of it, but where it peaks may turn out to be different than the MR/HR/TPs of the past

As far as the converter, I do not think you will have a choice in the end, small-ish motor, big cam, high rpm, it'll need to be loose and strong enough to handle the RPM and power.  Dyno is a benefit again as it will help you pick a gear and a converter

[gregaba]

When we had the block machined we ran a sonic check on the cylinders and magged  the block and also ran a pressure check. We checked the cam bores for correct alignment and had to align bore the new main caps.
I am picking up the block Saturday and will be dropping off my crank assembly at that time. I don't have much choice on the crank because it is the only one I have. It will be checked and if it is suspect I will order a new replacement. It will be balanced using [rods bearings pistons etc.] all the assembly
Hope I can use it or the build will take longer then it should.
I am planning on breaking it in on a dyno. The Street Outlaws racers have a shop 6 blocks from my house and I talked to them about doing a dyno break in and tune on the engine. The guy who owns the shop runs the red 55 Chevy on the show. It will be interesting to see how the cam works with the TFS heads and the single plane intake with the FE power adapter. If the cam doesn't work out I have 3 more new cams I can use or I can take the dyno results and use them to select a better cam.
The converter is where I am at  this time at a loss on. I have all ways ran manual trans and not that up on converter technology. The rear gears I am open on as I am trying to get a rear with some street ability and a little drag use with the street use being more important.
I don't really want to worry about excessive heat from the converter but can live with it.
This is just a hotter then stock engine and not really a race engine but I still would like a good runner.
Thanks everyone for the help on this.
Greg

[My427stang]

So the dyno will set you free......

When you dyno you will end up with the HP and torque curve for the engine. 

If it were pure race, you'd likely gear for trap speed, but being a street car, a bit of spit balling is likely in order.  I would probably gear for OD cruise at where you anticipate it would be comfortable.  For example, my 489 with a upper 240s cam, we started at OD X final at 2.36 and it was a little too tall, so it ended  up at 2.63 using 4.11s. and a .64 OD

For yours, 2.63 will be too tall, almost guaranteed, smaller motor, bigger cam, bigger car, a 6R80 has a 4.17 1st and a .69 OD.    There will always be enough 1st gear, so say you go for a 3.00:1 compound in OD that would be a 4.33 gear in the rear, likely pretty good, especially if you retain a lock up converter.  However, be sure to run a good balanced driveshaft because it will be spinning fast on the highway

I sure wouldn't go lower, because 1st is so low, but 1st being low in an automatic isn't as bad for a street car as a bad OD choice because it can shift very quickly.  Lets say you wanted taller gears, and you went 2.87 final, a 4.11 would be pretty close.  I wouldn't go taller than a 4.11 though, it does tame down 1st a little, but the the dyno will tell you if it will be happy.  My gut says 4.30s for that combo even though 1st will be so short

As far as the converter, after you pick a gear, know the weight of the car and have the torque curve, you call a good converter company and they give you what you need.  In your case, I suspect the converter will  be loose, but as long as the lockup works, it won't run hot when cruising long distances, but failure to run a loose converter with that cam will likely make it very fussy to idle and worse to drop in gear at the rpm the cam wants to idle at.  The converter does two things in this case, loosens up for idle and when in drive, and creates torque multiplication for an engine that may be soft due to the big cam....both good for you.

So, short version....dyno > gear choice > converter > cool tranny as required.  Don't jump ahead

[gregaba]

Thanks for the help.
The reason I haven't ordered a rear pumpkin yet is because I wasn't sure what ratio to order. I like the ideal of a 300-1 final ratio in drive on the highway. That would give me a good MPG and still be low enough in first for good acceleration.
I would like a lock up converter anyway. Like I said I am not up on auto's but have heard about the benefits of the lock up. i guess the dyno will tell me.
I had planned to order an aluminum aftermarket driveshaft because I didn't get a shaft [or may be I did] with the 63 when I bought it and the stock one wouldn't work with the 6R80 anyway.
Not sure about the weight of the car because it was modified by the original owner and with the altered wheelbase and other mods he did to race it. I will get it on a trailer after I get the engine and tranny in it and weigh it.
I won't have the engine in the car until next year because this stuff is expensive and I have to do a little at a time.
Still have to change over to disc brakes and rebuild the front suspension and add the Culvert traction bars and leafs and am ordering the parts as I get the money.
Greg

[My427stang]

I think the 4.30s will be nice for the OD and still be able to handle the big cam, but don't worry about not having enough first gear.  That tranny has a 4.17:1 first gear, a C-6 is 2.40:1

So, your car with a 4.30 gear will be 4.30 X 4.17 = 17.9:1, A C-6 would need a 7.47:1 rear gear to match that tranny, you'll be out of 1st in a blink of the eye. 

In fact, even if the car had 3.00:1 on the rear, you'd still have 12.51 compound in 1st, which is equal to a C-6 and a 5.21 gear.  1st isn't an issue at all, and second will be like a normal C-6 in 1st.

As far as the lockup, just want to make sure you understand what it will do, generally programmed in higher gears, it locks the converter with a little solid clutch so the converter doesn't slip at all.  Not usually strong enough for racing, but in the top 2 OD gears it will usually lock and feel like it adds/splits another gear.  The fact it's locked keeps fluid cool and makes the tranny more efficient

As far as weight, just need to be close, it's a primarily street car, go with a 6 cyl AT version, close enough in my book, like I said, dyno, gears, weight then converter, why put the tranny in and take it out?  You can get pretty close

[gregaba]

It looks like right now a 4.30 will be about what I need. I think the 6R80 has a lock up converter stock with 3 clutch's if I was reading the articles right.
Regardless it looks like I will need a good aftermarket converter.
As far as the weight I am not concerned a lot with it except to build the drive train to handle it. The car has no under layment, carpet or other heavy items in it. I don't think it ever had any of these items since it was a week old.  i am going to add some insulation and carpet. I took out the roll bar and some other heavy items for the street so may be the weight will equal out.
I checked the weight on another site and it said it weighed 3600 pounds with a 289-auto.
Thanks again for the help.
Greg