Blowing 3 Gees on my Six

[170-3tree]

I agree with fsd. Either cam will perform better with a higher stall than stock. Which one to get, I do not know.

If your truly undecided on the cam, I was told that 274 would be relatively mild in a 250. Maybe not as mild as a you want, but the 264, may be too mild. If you git on the horn with clay Smith and talk with them, they can set up a grind in grey area for you. I almost had them do a 268 grind for me but some of my friends talked me into more. It's only $20 extra too!

Fsd is the guy to talk to about which stall to select, but you can also find countless posts of people on the forum with so many various cams on different engines that have so many drivability issuesor even idle issues that are only remedied by either less cam or more stall. And while the engine is out of the car, get that distributor curved, if not by fsd then someone who knows what they are doin. It will take that much more guesswork out of gettin the very most out of your car and the new build.


Hope that gives a teeny bit more insight.
Gerald.

 

[Luke76]

Guys, thanks for all this good advice. FSD, I would not have given a second thought to my torque converter if you hadn't brought it up so I'm glad you did. I get what you're saying now about the stall speed, you got to go easy on us newbies. I would be happy for any specific suggestions you have but I'm guessing we need to know the cam profile first.

Gerald, that is also an excellent idea to about the re-curve, I am pretty certain I could benefit from it just judging from existing performance. I didn't know Faron did that but I just Googled him and now I do. Faron I will PM you about doing a re-curve if you don't mind.

Still the cam has to be settled. The more I think about it the more I agree with Richard that a dual pattern cam doesn't make the most sense for this engine. I do not believe exhaust is the bottleneck in my build. I asked Mike what he thought (I know he's busy, so may not get an answer). The custom grind is also a good option, but if I don't know better to decide between 264 and 274 I sure don't know better to decide in-between.


Luke

 

[MPGmustang]

luke,

i would look in a different direction... most CSC are HP geared... why not stay 'stock' ish and go with an isky 256 cam?
256: 256/256 - 202/202 - .450/.450 - 112* - 1500-4800

okay, roll with this one here... you get to keep stock converter
112 lobe center will help keep high vacuum if you have power brakes....
.450 will help engine breath better, with 1.6 rockers it will lift to .480....
duration, low and tame/smooth...

but knowing what I have seen, my 264/274 110 is 'rough' in my 200 compared to Gene's 278 cam with his 2800 stall TC... from what I have seen, his is really tame for the 250 and he's pushing close to 165hp at the tires... I think a 264/264 cam can get away with a stock converter... but I'm the guy that would try and test it for my own understanding... I have tested alot of theories...

 

[Luke76]

Richard,

I don't mind replacing the TC if the cam calls for it, so I don't want that to be part of the decision. The cam needs to have some other selling point besides letting me keep the stock TC. I want to get the most performance out of this build that I can, without going overboard. I can tell you right now with everything I've done so far, but with the stock cam, I am rather disappointed in the improvements.

When you say Gene's 278 cam is "tame" in his 250, can you describe what you mean by that word? Are you talking about his engine or the TC? I just looked up the specs on Gene's build and they look remarkably close to mine, at least on the engine. If by tame you mean his 278 has a smooth idle and is nicely mannered, then it would stand to reason a 264 or 274 should work quite well on my build.

 

[xctasy]

.....

but knowing what I have seen, my 264/274 110 is 'rough' in my 200 compared to Gene's 278 cam with his 2800 stall TC... from what I have seen, his is really tame for the 250 and he's pushing close to 165hp at the tires... I think a 264/264 cam can get away with a stock converter... but I'm the guy that would try and test it for my own understanding... I have tested alot of theories...

The extra 25% capacity makes the 278 cam really mild on a 250, but gives heaps of chop on a 200 cubic inch engine. Deal is that the extra 0.784 inches of stroke is a massive change to the dynamics of a 3.68" bore engine...the 250 is darn near a tractor verses the already torquey 200.

Rod to stroke ratio is the same with both engines. The air speed is at any given time, 25% more with the 250 because of the increased stroke.

Regards torque converter, I'd be conservative and follow FSD's advice. I know that stock C9 versions on the 1969 to 1980 200 and 250 Falcons in Australia ran a 1650 stall converter, factor rated, but it was the same as the 302W and 302C 2 and 4V stall converters, no change from 1969 to 1982. When the GT spec 351C was used with 280, 290 or 300 degree cam , a step up to 2350 was made. Same with the 1983 5.0 liter Fords. Stock, 1650. 5.0 4v, 2350 rpm.

I'll bow to superior knowledge as to what running a 1650 rated with 2 or 4-bbl stockish 302W making 140 to 160 hp net stock, and 210 to 240 lb-ft stock would be on a stock 87 hp/159 lb-ft 200 or 99 hp/200 lb-ft 250 is, but the V8's have less torque off idle than a 250, so I'd say 1650 would be the same with each engine.


Over here with C4 or Borg Warner 35/40/51 s , we use a nominal Use a 2350 to 2500 'call' stall converter to be safe. Our six cylinder C4's are the same between 200, 250 and 302W, as the bellhousing was separte and the 200 was a tall deck 250 with a really long 6.27" rod and the earlier short deck 200 stroke.

 

[chad]

or 99 hp/200 lb-ft 250 is, but the V8's have less torque off idle than a 250,

just wanna utilize that - 1000 to 2500 rpm
Hope this aint a jack, we're on cam - how to spec that for the 250?

 

[Luke76]

Ok guys, I've decided to go with the 264 single pattern, 112* cam. Gotta make a call at some point so that's the one.

FSD or anyone else, if you have a recommendation on a specific brand or model of TC to look at, I'm all ears. It sounds like something around ~2500 RPM might be what I want.



Luke

 

[MPGmustang]

yes, tame as in nice idle in gear, smooth running, but there are a lot of little things to consider... higher CR gives him less initial and max timing. he also has a 500cfm carb... and his stall converter is 2800, his mpg won't be pretty..

I think you should stick to the 264 or lower cam.

reason why, from my view point...
C4, PS, AC...
all of these will lower the idle, cams with more duration drop lower with more accessories.

You'll be happy with the 264, and with the 1.6 rockers you'll be closer to 270 air flow without the extra duration...

BTW any after market cam is a better choice than stock, cause you get better breathing time or lift and ramp rate and more overlap that really helps the engine. you were disappointed because the cam was holding you back.

what is your rear gear again? IIRC i think it was around 3.00's? if so I'd consider going to 3.2's or 3.5's...

for the TC... I think what xctasy mentioned, go for a 2300 stall speed, I still think the stock will be good for the cam, but to be safe a 2300 will be just as good, anything higher and I fear you will loose engine efficiency.

another thing to look into, is the carb and timing as mentioned, timing can be little off and FSD will do a great job for you. the carb, I'd run it on a dyno, not for HP readings although that's a good thing to see, but for AF at WOT, here it's 65$ for 30min... it's cheaper than a wideband...

 

[Luke76]

Yeah, my rear diff is 2.8 which I agree could be changed. It's on the list of things to do but probably will have to wait until my wallet recuperates. :roll:

Here's a B&M 2400 torque converter for a fairly reasonable price, so far as they go. They also have a 3000 RPM, FSD you implied maybe a TC rated at one thing will actually perform at another. Would you say the B&M 2400 is too little for my application? It sounds pretty much like it would be in the sweet spot to me, but I'm no expert.

TCI is another brand I hear about a lot, but their website is kind of a mess to figure out... and they don't seem to even provide any sort of stall ratings, they just group their converters into non-helpful categories like "street fighter", "saturday night special", and "sizzler", whatever those mean.



Luke

 

[xctasy]

FSD says that the rating is just a number, and that if you have a 250 then the stall rating listed is wrong wrong wrong when whacked behind a 250. His recomendations were based on experience of where the torque sets in, so the same converter in a 220 ft-pound 250 will flat line at a different point than the same verter in a 5.0 GT with 220 ft pounds. In practice, little pip squeek 3000 stall converters can be just right for a low end torque 250.

I'd just like to say that the off idle peformance characteristics can be tailored with cam, compression, stall and ignition timing. FSP finds that if you run the right amount of spark lead and compression, the off idle hole can be worked around.

Talk with him. Your engines are different to our cross flows, so what we do down here might not apply to you.

 

[Luke76]

Just an update to the thread...

We've had a hell of a time finding the pistons I chose for this build (Tempo flat-tops) and I won't bore you with the details. Sourcing parts on this build has been one of the biggest challenges (other than my own incompetence) and has set me back about two years total. But we did finally scrounge up six working pistons and I think now I'm in business. The block is still at the shop but should be ready soon.

In the meantime I have not been idle. The DUI distributor was re-curved by FalconSedan (Faron Rhoads) and I have high hopes for the improvement that will bring.

I also took the cylinder head to "Rick's Cylinder Head Services" in Milwaukie, Oregon. They are experienced in welding cast heads and I had them weld over the gaping hole in the port divider left by Portland Engine Rebuilders when they installed the divider two years ago. Rick's did a great job and I am pleased with the result. I've attached some before-and-after photos below.

BEFORE





AFTER

 

[Luke76]

By the way, my 264/274 - 112* Clay Smith Cam is for sale in the sale section, click here.

If you recall I decided to go with the 264 single pattern...


Luke

 

[bubba22349]

Nice job

 

[MPGmustang]

that sir is nice and clean. well done!!

Luke, recently i've been play'n with rear gears and to be honest, I wish I did it sooner!! went from 3.2 to 4.11 to 3.8, the 4.11 should have been really good, but I didn't calculate tire squish which is an extra 300 rpm. the 3.8 is great but with little bigger tires I'm equivilent to a 3.70, and I'm as happy as a clam on RPM's. really think you should look into it.

 

[Luke76]

Richard, I've been reading your "Basics" thread - at one point you said the switch to 3.8 dropped you 250 rpm at 70mph, but I didn't catch what your original RPM was... Where are you at 70 mph now with the new tires and 3.8?

With my 25.5" tires (195/75R14) I'm right at 2900-3000 at 70mph (2.8 rear), which seems a bit high compared to what the calculators predict. Of course my tach may not be very accurate. Either way I do think the 2.8 rear is too low but I want to finish the engine first before experimenting with the rear gears.

Have you had your DUI recurved by FSD yet? I got mine back just a few days ago, haven't had a chance to talk to him about it yet. From visual inspection the first thing I noticed is vac advance seems to have been set to full with a nylon spacer. Not sure the actual advance specs now with the re-work, hopefully he will post here as I think it might be of general interest.


Luke

 

[64falconsix]

I Fell asleep reading this thread on my smart phone. you seem to have learned alot for a newbe to the automotive world, I admire your patience and persistance. I have been building hotrods for 35 years and built several race engines for friends and family and still research and ask questions. with your cars weight and engine specs I think you will be happy with your cam choice especialy with the higher ratio rockers, it should work well with the auto trans and high rear axle ratio and stock converter. One thing I did not see or maybe I missed was your spring choice, open and closed specs at installed height and coil bind height. Does your granada run the 8" rear axle?
if so changing the gear ratio to something with a little more snap is as easy as changing the chunk. If you do a lot of highway driving though I would stick with a 2.78 or 3.00. Back in the day I had a couple of chunks with different ratios and would swap in the lower gears when I was hitting the track.

 

[Luke76]

Hi 64Falcon - yeah, the thread is getting pretty long. I think when I finally get the engine back and start reinstalling it I might start a new thread, this one has been winding all over the place.

I have the 289 SBF springs on the head now, although I think CI recommends the 302 for the 264 cam. At the very least I'll break in the engine with the 289s and probably I'll just keep them on there because I don't anticipate much revving at extreme RPMs. As for spring specs and coil bind, it's something I need to check, thanks for reminding me.

PS: Yes, I have the 8 inch rear. Good to know it's an easy swap for the gears.

 

[FalconSedanDelivery]

Luke your Vac advance has been limited on when it comes in and how much ,doesn't start till 10 inches and isn't all in till 15 Its Not , also the Mechanical advance has been limited to 9 degrees ( 18 crank , and has a very progressive curve , with it all in by 3100) , before it had 12 all in by 3000 , BUT , it had 10 at just over 2000 WAY TOO QUICK !! , the Late Heads are VERY Detonation prone and do not like much over 34 degrees total ( depends on compression , cam , octane , vehicle weight and altitude where car is driven most , sorry been busy assembling Dists and 3 Engines for customers

 

[MPGmustang]

With my 25.5" tires (195/75R14) I'm right at 2900-3000 at 70mph (2.8 rear), which seems a bit high compared to what the calculators predict. Of course my tach may not be very accurate. Either way I do think the 2.8 rear is too low but I want to finish the engine first before experimenting with the rear gears.

That's something I forgot... you have a 1:1 final drive, mine is a .68:1 final drive... that greatly affects your handling and acceleration. for you I think your TC will make the difference on acceleration.

First, had 195/70-14 (24.74 in) with 3.2 rear gear, 70mph was roughly 2000rpm it always seemed to need more RPM. could easily down shift to 4th for a 3000rpm passing gear. I wanted somewhere in the middle for cruising.

with my 4.11 gear I have an equiv of 2.79 final drive (4.11*.68) and that with 24 inch tires gave me "2650" rpm, but it read 2900-3100 on the tach (think I need a filter for the DUI as the noise affect tach needle)honestly I really didn't like it, passing gear was 3600-3800rpm and it didn't help.

with 3.8 I went and changed tires right away, and I'm happy as I think I'm where I'm supposed to be (3.8*.68 = 2.5 OD final gear). tires are 225/70-14 (26.40in) I calculate to 2300rpm, but tach reads 2600rpm, and passing is 3400rpm. all at 70mph. with the higher gear I have more vacuum available to cruise with, not as much as I hoped for but enough to easily stay out of the power valve.

If I had an auto with a 250ci i6, I would try and look into an AOD, mod the block to accept the bell housing top bolts, and run a 3.5 rear gear with your tires. you'll be in the same ball park cruise RPM as I am with 3.8 gear and 1inch bigger tires the main benefit is a lower take off gear. that makes the difference in traffic. but an auto with my 200ci, I would go switch out to 2.8 rear gears and try to get even bigger tires, I think I can run 27.5 or 28 inch tires safely in the back, the front would be my limiting factor. but I don't mind different sizes on front to back.

the last thing to affect accel is the carb/ignition, I didn't send it in to FSD, I'm still in the middle of what to do, so I'm fiddling with a mr gasket kit #929 for $6 and put stronger springs on to limit advance curve, running close to 19* static. and have the vacuum canister give a total 20* with 15inch vacuum (15 is all I make) so with a light pedal I get great mpg (21 city so far) and with a heavy pedal horrible mpg (lowest was 14mpg so far) but it's easier to drive. I even think I can run more static of like 22* then the carb, I changed jets in spring to something smaller, but now with hotter (dryer) weather I need even more leaner jets, so I'm pig rich with only a 2 month old tune... I have adjusted the carb since but still the jets need to be smaller.

sorry for the long winded reply, and late response... hope it helps. IMO keep your rear gear, hope the TC helps you accel better.

 

[bubba22349]

No block Mods needed for a 250 the SBF V8 AOD trans will bolt right up.