Clevelands and FE are done, will start my first 5.0 !

[westcott cobra]

Hi all,

recently i sold my 427 Crendon Cobra with 433 FE and now I'm in the middle of rebuilding my AC MK IV with small block 5.0 HO power.

My first idea was to use my old hi reving Cleveland for the project but finally i want to stay with the "original" engine family.

After a short inspection of the engine internals i found out that i have to rebuild the engine. It is running but has some marks in the cylinder walls from former head gasket failures and some scratches and skuffs deep enough to bore it.

Because all the parts plus machine shop work, hottanking, cleaning, painting and so on are just a bit cheaper as a new shortblock from the US I decided to build a new one and keep the old one as a spare unit, just in case...

What i want is more torque over a broad rpm band and just a bit more HP as it has today.

Engine has to be very streetable and healthy, therefore these are my ideas:

-CR: 9,2:1
-Catalytic absorber, to be specified, maybe the original ones
-AFR 165 heads, KC ported, complete, sitting at home
-Lunati Voodoo hydr. roller tapped 61010
-COMP Cams 1634-16 - COMP Cams Ultra Pro Magnum Rocker Arms, 1:6
-JBA Headers 1621SJS - Cat4ward Headers, Stainless
-Weiand Stealth Intake 8020
-331 Shortblock, KC Street Performance
-Canton Oil pan 15-644, road race wet sump

For the carb I don't know right now.
A Holley Commander 950 TBI EFI with different jets is sitting on the shelf from a former project but i want to drive the engine the first few hundred miles with a carb.

Any recommendations for a carb matching the components above or the components in detail ?

I know that sooooo much posts as my one appeared in the last few years, sorry for this newest one.

Greetings from Germany,
Uwe

[YerDugliness]

If it were me building for street use, I'd use a Holley-style center pivot carb in the 600-650CFM range on the 5.0, certainly ask the advice of the cam manufacturer....or get a custom built QuickFuel from blykins.

The 5.0 in mine ran like a dog with a Holley 780CFM (#3310)....runs like a scalded-assed ape with the Edelbrock 575CFM Thunder Series carb (totally street driven, though) !!

Sounds like a great motor you're building there....ought to be really tractable, as well as trackable, with that EFI setup!!

Cheers from Dugly

[DAVID GAGNARD]

For the carb I don't know right now.
A Holley Commander 950 TBI EFI with different jets is sitting on the shelf from a former project but i want to drive the engine the first few hundred miles with a carb.

Any recommendations for a carb matching the components above or the components in detail ?

Using Holley's formula for determining carb cfm requirements of a given engine (cubic inches X max rpms diveded by 3456) assuming a 6000 rpm redline, your engine would need 574.66 cfms of air, also, assuming 100% VE....Add in antoher 50 cfm so you don't max out the carb and you need 624.66 cfms of air, so a 650 double pumper would be perfect....you would have good idle vacum and good low end torque as well as enough carb to see it through the rpm range......
a lot of times when it comes to carbs,bigger is not better.....

David

[Mark O'Neal]

Originally Posted by DAVID GAGNARD

Using Holley's formula for determining carb cfm requirements of a given engine (cubic inches X max rpms diveded by 3456) assuming a 6000 rpm redline, your engine would need 574.66 cfms of air, also, assuming 100% VE....Add in antoher 50 cfm so you don't max out the carb and you need 624.66 cfms of air, so a 650 double pumper would be perfect....you would have good idle vacum and good low end torque as well as enough carb to see it through the rpm range......
a lot of times when it comes to carbs,bigger is not better.....

David

I used to use that formula, with pretty much the same result.

Then I found out the motor made more power with a 780.

[olddog]

First let me say I'm just an egg head that reads and thinks about engines. There are much more qualified people on this site than I. My comments are more to provoke thought rather than a recommendation.

I got the impression you are wanting a very street friendly, not too wild, engine. You did mention good torque over a wide rpm range, so I'm not too sure where you are wanting to limit the rpm. I didn't look up the cam specs (I'm lazy), but I assume it to be more to the mild side. From those assumptions, I'm guessing a 6000 rpm top end.

If you are going to limit the rpm to 6K, consider a 347 stroker. It would cost about the same as the 331. It would give a bit more torque.

An aftermarket block would allow you a 4.125" bore or more. That would set you back more money, but it would also step up the power and reliability. From what you said I doubt you are looking that direction, but thought I would put it out as food for thought.

If you step up the displacement, you may want to consider the AFR-185 heads, but KC would know what is best there.

You may be better off to error on the smaller side for a carb. I would consider a 600 CFM with what you described. a 650 cfm, if you go with more displacement.

[westcott cobra]

I don't want to rev higher then 6K. What i want is a "bit" more HP and as much as torque i can get out of a 331.
The 347 i don't want to build because i really don't like the piston designs with small ring groove distances or open groove for the oil control ring in the pin area .

My MK IV has to be a cruiser with the ability to go a bit faster if needed It is a long nose body and looks very british with its green metallic paint, it will be a bit of cobra understatement with rear exhaust and small tires.

No track use, no strip, just going across the country to as much as possible cobra meetings with a smooth running healthy small block 5.0 with a bit more potential and a nice firing order.

The main cam specs of the 61010 Voodoo are:
Basic Operating RPM Range 1,600-5,600
Intake Duration at 050 inch Lift 211
Exhaust Duration at 050 inch Lift 219
Duration at 050 inch Lift 211 int./219 exh.
Advertised Intake Duration 262
Advertised Exhaust Duration 279
Advertised Duration 262 int./279 exh.
Intake Valve Lift with Factory Rocker Arm Ratio 0.541 in.
Exhaust Valve Lift with Factory Rocker Arm Ratio 0.549 in.
Valve Lift with Factory Rocker Arm Ratio 0.541 int./0.549 exh.
Lobe Separation (degrees) 112

Must be enough to achieve 270 or so real rear wheel horses and close to 400 lb/feet.

No? Yes?

For carb size I have 600 cfm in mind. By "i don't know now" i meant the manufacturer. My last carb on the FE was a Quickfuel HR series vac secondary with e-choke.

Is there any other not too expensive carb available with screw in air bleeds you made good experiences with? (Never ever BG .....)

Westcott

[blykins]

Originally Posted by westcott cobra

I don't want to rev higher then 6K. What i want is a "bit" more HP and as much as torque i can get out of a 331.
The 349 i don't want to build because i really don't like the piston designs with small ring groove distances or open groove for the oil control ring in the pin area .

My MK IV has to be a cruiser with the ability to go a bit faster if needed It is a long nose body and looks very british with its green metallic paint, it will be a bit of cobra understatement with rear exhaust and small tires.

No track use, no strip, just going across the country to as much as possible cobra meetings with a smooth running healthy small block 5.0 with a bit more potential and a nice firing order.

The main cam specs of the 61010 Voodoo are:
Basic Operating RPM Range 1,600-5,600
Intake Duration at 050 inch Lift 211
Exhaust Duration at 050 inch Lift 219
Duration at 050 inch Lift 211 int./219 exh.
Advertised Intake Duration 262
Advertised Exhaust Duration 279
Advertised Duration 262 int./279 exh.
Intake Valve Lift with Factory Rocker Arm Ratio 0.541 in.
Exhaust Valve Lift with Factory Rocker Arm Ratio 0.549 in.
Valve Lift with Factory Rocker Arm Ratio 0.541 int./0.549 exh.
Lobe Separation (degrees) 112

Must be enough to achieve 270 or so real rear wheel horses and close to 400 lb/feet.

No? Yes?

For carb size I have 600 cfm in mind. By "i don't know now" i meant the manufacturer. My last carb on the FE was a Quickfuel HR series vac secondary with e-choke.

Is there any other not too expensive carb available with screw in air bleeds you made good experiences with? (Never ever BG .....)

Westcott

I wouldn't let the oil rings get in the way of adding more stroke. It's a non-issue. A lot of guys say that, but if they knew how many 347's there were running around, it would change their minds. How much difference does .150" of stroke make? It can make a lot. Plus if you're making 1.4 hp/ci, another 20hp is quite a chunk.

With the cam that you listed, you probably won't be able to rev past 5000-5200. I would use a larger cam than that for a 302, much less for a 331. I would also limit the amount of split that is in the intake/exhaust durations. Eight degrees is too much in my opinion and this only adds to overlap and reversion. I like the 112° LSA, but I would limit the split to a single pattern cam for a street car. Of course this all depends on the cylinder head choice as well, as more flow will make a cam more efficient. The AFR 185 would be a great head for this combination.

It's hard to beat the Quick Fuel carbs and I would go with a 600-650 cfm carb as well.

[westcott cobra]

Brent,

I see your arguments regarding the 347 but will stay with the 331.

The KC cnc ported 165 AFRs are on my shelf since a month because i planned to drive my 5.0 without rework, just remove the emission parts, add new heads, cam and intake.

After the internal inspection i decided the rebuild, the decision for the 331 was made 1 month after the heads arrived...

Shipping costs to the US and back to Germany to exchange them for 185s are about 400 USD for these heads.

For the carb I will go again for the QF HR Series, for the 331 SBF the 600 cfm should be big enough for my planned rpm limit below 6000.

Can You send me a quote for a custom build/adjusted 600 cfm QF HR series inclusive shipping to Germany by mail to uwe.mueller@jci.com?

Thanks,
Uwe

[blykins]

So what are your arguments against the 347? I've never sold a 331 or even built one. The 347 components are the same price and I've never had an issue with oil consumption or piston instability, even on 347 drag race engines.

I'll send you a price on a custom HR 600.

[westcott cobra]

Deleted, was my doubled answer...

[westcott cobra]

Again doubled...I#m a bit stupid today.....

Westcott

[olddog]

Well it depends on how much port work KC did on the heads, but I would add 10 to 15 onto the duration. If the springs can take it, a bit more lift would help, too. A little chop to the idle, but far from radical.

I wasn't a fan of the 347, same as you. I have owned one for 4 years now. I can say in theory I like the 331 stroke better, but in reality there is nothing wrong with the 347 stroke. If your mind is made up, that's fine. It's your engine.

I still like the 4.125" bore blocks. Much stronger and better oil paths. Although you should be fine with a factory block, with what you are building. It would help with your power goals. I don't see a 331 that mild making 400 lb-ft at the wheels, flywheel maybe. I doubt 270 Hp at the wheels, but it might.

[Marcus521]

Deleted, was my doubled answer...
__________________

[olddog]

I pulled a book I have that is full of SB Ford combinations that were dynoed, and read through it last night. Interestingly they did a 302 with AFR-165 heads (out of the box - no port work) and a cam very close to the one you mentioned. it had a very flat torque curve. I was surprised to see that it pulled all the way to 5800 rpm where the valves floated. A comment that the springs were of poor quality and AFR no longer used those springs. It looked like the the engine would have peaked on Hp a bit north of 6000 rpm had it not floated.

They also did a 331 with AFR-185 heads (out of the box) and a cam a bit bigger like I suggested. The engine had a big step up in torque. Still fairly flat curve, but the torque did start dropping off more quickly by 5500 rpm.

If the port work on your AFR-165 heads improved the flow a fair amount, you may be fairly close to an out of the box set of AFR-185 heads. Since the short block and heads are already picked, the only thing left to work with is the cam, intake and exhaust. As I said a little more cam. I like the Edel air gap (dual plane) intake. I believe in step tube headers. I don't know enough on headers to say much more. Other than exhaust can make a huge difference on power.

Good luck.

[blykins]

[quote=olddog;1163837 I was surprised to see that it pulled all the way to 5800 rpm where the valves floated. [/QUOTE]

It would be much lower with 30+ cubic inches more displacement.

[westcott cobra]

For the headers I'm limited by the package dimensions comming with my MK IVs foot box design and inner fenders.
Shorty headers just fit in tight, the equal length headers are too "fat" and will interfere with the footboxes.
I think I have to stay with the best shorty headers for the 302 or weld my own headers.

The 4-tube-pack of a step tube header will not go between the footboxes and the round 4" frame tubes. I will bring up a pic here.

Some MK IV owners mount the shortys the opposit way to clear the boxes and frame and allow the biggest length underneath the floor for cats and tubes.

The KC 165 should flow just a bit more then stock AFR-185s.

Westcott

[Barry_R]

I actually prefer the 5.315 rod 347 combination. The extra rod length is near to meaningless. And I have several 331s running out there that do just fine as well.

I actually do not like the oil rings perforating the pin bore. What is considered an acceptable degree of oil control in a hot rod would be considered totally unacceptable in any OEM application. Most performance guys will never know since they change the oil every time the wind changes direction. Add to that the fact that the ring groove spacers are nowhere near as well made as the rings nor the pistons - it's an uncontrolled and un-necesary variable - you can often readily feel the difference in ring drag when turning the engine over on the stand.

The oft quoted carb formula is inherently flawed. Back when carb companies used SAE standards instead of making up cool sounding number, the carbs were rated at 1.5" of vacuum drop below the plates. You NEED some sort of reference restriction in order to derive a rating - but the values arrived at reflect a restriction in airflow into the engine - exactly the opposite of what you want.

[Keithc8]

I do not know how much power you are looking for but a nice 331C.I. with the KC 165 heads, hydraulic roler around 224/232 and a Performaer RPM intake should make a easy 425 to 435HP and I would think about the same torque.
If you have to run the header that you are talking about anything bigger or with a better head would be limited anyway. The exhaust on these cars kills more power than most people know. I have people buy big heads and then stick small tube headers on them covering part of the exhaust opening and the pipe size will not the exhaust flow as it should. The header pipe size and bolt pattern need to be considered when getting headers. This will in turn have a lot to do with the engine size and other things. It all has to work together.
I think you will be surprised at how well the engine will work for you.

Good luck, Keith Craft

[westcott cobra]

Thanks Barry and Keith for your input.

The headers will be JBA shortys with 1-5/8 primaries and 2-1/2 collector, this shoud not be too restrictive and will clear my footboxes.

Uwe

[Keithc8]

Uwe let me know when we can send some more parts to Germany. Good luck with your project. I think the headers will work pretty well with that project.

Thanks, Keith