big block vs small block?

[wwhite72]

Cleveland heads on a windsor started with the Boss 302. The 302's are the predecessor to the 351 windsor. The trans am series had displacement restrictions so ford was limited to the 302. They won so often because the cleveland heads of the time crushed the windsor heads. Today the aftermarket has improved the windsor heads, but the canted valve design still breathes better because the valves can be bigger. So many oher factors come in to play....no way to do apples to apples today. But in 1969 it was newer design technology.

 

[Mesozoic]

So grab an early '69-74 351W block, or the new Boss 351 block (or a Dart block for that matter), and bolt on a set of Kaase C-400 heads and be done with it.

 

[woodsnake]

I just went through this whole thread, and I have a couple of questions...

The OP never said what car this was going in, so I will ass-u-me it is a 71/3 mustang. I get the argument for and against the BBF/SBF engine, but there are a lot of other things to be considered here other than just a 500 hp engine. Rear end gear, and transmission selection also play a pretty big part in planning one of these builds..

I see mention of twisty roads, which is cool, and daily driver, which is cool. But nothing about a commute, or traffic. I would think that a with the afore mentioned AFR heads, A nice roller cam, and a 3.89 gear, an engine built either in Windsor, Ontario or Cleveland, Ohio would fit the build..

 

[cazsper]

My apologies. The car in question is a '73 Mach-1. The transmission I'm planning is a manual (T-56 or at least a TKO-600) with 3.50:1 or 3.73:1 gears with a Detroit TruTrac (275/40-17's in the rear). Living in the California bay area, I am in traffic as much as I am cruising the freeway. Whenever I can, I drive over the mountains to the beach or the occasional trip to Lake Tahoe (about 4 1/2 hrs away).

 

[woodsnake]

I wouldn't use anything less than a 3.5 gear..In my 68 Cougar, I have a 289, that was bored .030 over, and .010 over and under on the rods and mains. I decided on the Edelbrock performer RPM cam( 496/.520 lift), thinking it would be a nice, medium street cam...

I also recently added a pair of performer RPM heads, and have the Edelbrock dual quad air gap intake.

At 70 MPH, in 5th gear, (T-5 trans) I am below the power band, and so I need to down shift to pass anything on the interstate. Sucky.

I also get a 'lean surge' condition at cruise.

One of these days, I will change up the rear end up to a 3.73, or 3.89. The engine will be "on cam" at cruise, and probably be more efficient, with the cam and heads I have on it.

In my 69 Cougar, I have a 351W, that I went ahead and payed for the retro roller cam conversion. That engine has Trick Flow fast as cast 170 heads on it, and only a .513 lift cam. It also already has a 3.89 gear in the rear, with T5. I am looking forward to finishing it up!!

I expect the 69 to have a really great mid range, pretty good torque, pull plenty hard, and still be plenty street able.

So, there is my free advice, that is worth what it cost.

I Think you will be happy with a 205 headed, roller cammed Windsor, with a 3.89 gear..

 

[cazsper]

Hmm.. I've used 3.50 gears in a lot of my cars. I'm surprised your having issues with them. Do you think your dual quad setup could be part of the issue? From what I've read, a dual quad setup is primarily for higher RPM setups.

 

[Finmach]

When it was better at the job than a 427 side oiler...Good read http://www.7173mustangs.com/thread-the-amazing-351c-4v

Cleveland was made to hang with much bigger motors in racing...Like the 426 hemi...Kinda funny how with the same lift it makes the same power of any of the monster big blocks of the era with less cubes....Counts how crazy you wanna go..But block can handle over 750 hp...You have to get a dart block to hang with a stock Cleveland 70's block ..It can handle as much HP as a Gen 4 big block chevy.....It's a well webbed and built up in the right places.....And head's are still good racers to this day..Only reason not being used today as much...Cast iron and heavy....If they made cheaper aftermarket heads for them they would be the kings still, thing the SBF has over a cleveland i think mostly is aftermarket parts.."dart blocks and aluminum heads and such"..Why should suppliers make race parts for a Engine not being made anymore? It is a shame really...Bad press killed it...And alot of Ford racers kept using it years after it was out of production.

And as for the heads...As posted above in the artical

"It's cylinder head is the ultimate canted valve cylinder head. It's basic architecture continues to influence the racing heads designed by Ford and Chevrolet to this day. If the design was faulty, this wouldn't be so"

"was capable of competing on equal ground with hemi headed 7 liter motors. With the same 0.6" lift endurance cams, at the same rpm, with the same carburetion, the 351 cubic inch Ford made equal horsepower as the FE427, the Boss 429, the 426 Hemi and the 421 Super Duty. It could power a Torino around the super ovals like Taladega and Daytona at equal speed, and with equal reliability as the big blocks. It could cruise around a super oval at 7200 rpm all day long without breaking. It did this with a thin cast block, no side oiling, no steel crank. The 351C 4V was assembled on an assembly line at 20% of the cost of a Boss 429 or the 427 FE. "

That will be the last thing i got to say about the Cleveland...Yes im a fan of the it..But i like them all

This is little offtopic but an reply for hyena429.

There was a time when bringing a 351c for nascar track was like going to gunfight with a knife - like the 1970 Nascar season. There is a reason for how did the barrels got even. 351c made an impact at Nascar stock car racing in the 1971 - 1973. 351c truly powered the torino’s at the super ovals at Talladega & Daytona at equal speed as did the Boss 429 and as did the 426 hemi. This was in 1973 season when Bud Moore was building cars for Bobby Isaac, Darrel Waltrip, Donnie Allison, George Follmer, Buddy Baker and Bobby Allison and all with race 351c engine. Bud Moore was one of the first Ford heroes who read the rule book and realized that by going with smaller engine you could f.ex. get rid of the restrictor plate (between the carb & intake) which the 7 liter needed to use to bring the speeds down.

Here’s a direct quote from a Dr. John Craft Ford, Lincoln & Mercury stock Cars book. “Even so, canny mechanic Bud Moore was laying the ground work for future Ford greatness that very season. You see, though Pearson was still mopping up on the high banks with the help of big block (Boss 429) power, sanctioning body was taking a jaundiced view of 7-liter powerplants. As a result, the ever-chasing rules book making life increasingly difficult for big-block-based teams. Innovative types like Moore (just back from the Trans-Am wars where small block reigned) quickly discovered that smaller displacement engines were far less regulated by the infernal rules book than mountain motors were”.

I hope Dr. Craft wont kick my butt for this, but I found this very intresting and relevant. Btw, I can only recommend Dr. Craft books from the Nascar - no wonder he has been granted the Dr. status, I mean he is a Dr. Nascar.

You can clearly see the powerdrop in Nascar from the average speeds per race at Talladega which needs big hp.

avg. speeds.

1969 Nichels Engineering ’69 Dodge 153.778 mph (247.482 km/h)

1970 Petty Enterprises ’70 Plymouth 152.321 mph (245.137 km/h)

1970 Petty Enterprises ’70 Plymouth 158.517 mph (255.108 km/h)1971 Wood Brothers ’69 Mercury 147.419 mph (237.248 km/h)


1971 Holman-Moody ’69 Mercury 145.945 mph (234.876 km/h)


1972 Wood Brothers ’71 Mercury 134.4 mph (216.296 km/h)1972 Hylton Engineering ’71 Mercury 148.728 mph (239.355 km/h)


1973 Purolator ’71 Mercury 131.956 mph (212.363 km/h)


1973 Eastern Airlines ’72 Plymouth 145.454 mph (234.086 km/h)


1974 Purolator ’73 Mercury 130.22 mph (209.569 km/h)


1974 STP ’74 Dodge 148.637 mph (239.208 km/h)


1975 Sunny King ’75 Ford 144.948 mph (233.271 km/h)


1975 Sunny King ’75 Ford 130.892 mph (210.650 km/h)


1976 Norris Industries Ford 169.887 mph (273.407 km/h)

1976 K&K Insurance Dodge 157.547 mph (253.547 km/h)

1977 Gatorade Chevrolet 164.877 mph (265.344 km/h)

1977 Hawaiian Tropic Chevrolet 162.524 mph (261.557 km/h)

1978 First National City Oldsmobile 155.699 mph (250.573 km/h)

1978 W.I.N. Oldsmobile 174.7 mph (281.15 km/h)

1979 Hodgdon/Moore Ford 154.77 mph (249.078 km/h)

1979 Gatorade Oldsmobile 161.229 mph (259.473 km/h)

1980 NAPA Oldsmobile 170.481 mph (274.363 km/h)

1980 Purolator Mercury 166.894 mph (268.590 km/h)

http://en.wikipedia.org/wiki/Talladega_Superspeedway

check the avg. speeds from there. By the development, disc brakes, better aerodynamics the stockcars started to fly again after a few years.

I wouldn’t ever go back to sbf, but I have an ol’ relation with 351c… so if I’re to build a stout SBF I would definitely go with canted valve head desing like CHI or P-38 heads instead of in-line desing. Canted valves gives you probably better valve shrouding, bigger valves and if your head mid-high lift is as excellent as P-38: s I would like to see how that performs in 0.050” 265-270 roller cam – should be nasty.

Otherwise I read back the ol messages and needed to say, that you can go with your existing suspension if going with BBF according my experiences. CHI 400 heads all the engines I can see them are having +4.100” bore so there might occure some valve shrouding with the stock 351w ’69-’74 block?

 

[droptop73]

One flaw in the average speeds is, that it is a race average including yellow flag laps. A better gage of performance would be to look at qualifying speeds but that is skewed by aerodynamic advances. Basically comparing speeds as a measure of power over a 20 year timeframe would tend to be inaccurate as there are many advances in chassis, tires and aero.

Big block fans will be big block fans and the same with small block fans. It is most optimal for overall performance to have a vehicle with 50/50 front to rear and side to side weight distribution. That, for me, means a smaller lighter engine in a relatively stock chassis. Like it or not a bigblock type engine hung over the front wheels is detrimental for handling, drivability and overall vehicle dynamics.

 

[wwhite72]

I agree that looking at avg speeds of races at a single track can be skewed by so many variables that the information is almost useless. I understand why you might pick a high bank to focus on big blocks...but then why not look at Daytona? But again, many variables come into play over this period of time. Ultimately it is all BS because we all need to turn right once in a while. The trans am series was a much better judge of real world performance car setup. But rules kept them with 302's....with Cleveland heads! Ha ha

 

[woodsnake]

The 3.50, would be an awesome gear for my car with a 4 speed, the engine is right in the sweet spot. However, with the over drive, it drops the RPM below the power band..

I have the dual quad from Edelbrock with the linkage hooked up to be progressive, instead of 1:1. I don't know if a richer jetting on the primary 2 barrels would help, or not....

http://www.summitracing.com/parts/edl-2035/overview/make/ford

I am convinced that a steeper gear would keep the car in the power band, even in Over Drive.

 

[Finmach]

I agree with you guys that there are several variables to the avg. speed, but it gives you a rough direction, similar results can be seen from the Daytona results from 1969 to the late seventies. Best would be the qual. top speeds for sure but it needs a sh#¤load of work to get them. I needed to go back to my books and checked the restrictorplate – it actually came in to play in 1970 to slow down the 426 hemi and 429 boss. Conventional wedge heads like 427 tunnel port could be used back then without restrictorplates. Just think the modern Nascar if they could run without the restrictorplates – could we see naturally aspirated 900 hp small blocks?

Ultimately it is all BS because we all need to turn right once in a while. The trans am series was a much better judge of real world performance car setup. But rules kept them with 302's....with Cleveland heads! Ha ha

Now I understand, when turning right use SBF and when turning left use you can trust to the BBF (@ nascar). Trans Am sanctioning body allowed for the season 1971 the 5,7 liters. Unluckily for the Boss 351 the Ford's racing budget was allready paralised for the 1971 with 85 % cut in funding. Many cool things were brough down. My friend has a '71 Boss 351, it's not a cannon, but a nice performer in stock trim, it runs 14.00s on quarter with the narrow period correct tires - no threat from the ricers.

I had 18 years ago a set of 351c 2v iron heads modified to be used with 302, I was going to build an old school street boss engine for my ol' '65 fb with mechanical flat tappet and Boss 302 rods. Unluckily or luckily I went to army and the engine project was abandoned.

 

[hyena429]

– could we see naturally aspirated 900 hp small blocks?

they could have 1000 hp naturally aspirated small blocks

 

[Mesozoic]

My N/A small block ran my '71 down the track in 12.30 with a bad tune when it was carb'd. Not sure if anyone's noticed, but they don't make big blocks for cars anymore. It's simply not even necessary with modern technology in design work. The McLaren F1 generates well over 600 hp out of a 6.1L V12 N/A. Don't get me wrong, I like big block Fords, but massive displacement used to be the cheapest method for generating big numbers. Nowadays, engineers are able to squeeze massive numbers out of smaller displacement engines via better machine tolerances, modern designs (Coates, DOHC, and variable valve timing valvetrains, computer control, for example), and highly efficient forced induction. My friend has an '85 Capri, driven on the street, generates 1000 hp with a turbo and a Dart based 304 cid SBF. I decided not to upgrade my fueling so i'm stuck at about 650 myself with a twin screw blower. All for about $10K in the motor, including the blower.

If you've got a big block in your old Ford, that's cool and I would keep it that way. If you don't, then unless you've got a raging compulsion towards big blocks, build an engine that's going to perform the way you want it to, regardless of whether it's an inline 6 or a turbo SBF.

 

[Finmach]

My N/A small block ran my '71 down the track in 12.30 with a bad tune when it was carb'd. Not sure if anyone's noticed, but they don't make big blocks for cars anymore. It's simply not even necessary with modern technology in design work. The McLaren F1 generates well over 600 hp out of a 6.1L V12 N/A. Don't get me wrong, I like big block Fords, but massive displacement used to be the cheapest method for generating big numbers. Nowadays, engineers are able to squeeze massive numbers out of smaller displacement engines via better machine tolerances, modern designs (Coates, DOHC, and variable valve timing valvetrains, computer control, for example), and highly efficient forced induction. My friend has an '85 Capri, driven on the street, generates 1000 hp with a turbo and a Dart based 304 cid SBF. I decided not to upgrade my fueling so i'm stuck at about 650 myself with a twin screw blower. All for about $10K in the motor, including the blower.

Yes exactly, these our pushrod engines are dinosaur’s. They don’t use either SBF:s for the production vehicles. Engine’s were used in production vehicles as following:

1962–2000 Windsor V8—small-block (221/255/260/289/289HP/302/351W/Boss 302)

1968–1997 385 V8—big-block (370/429/Boss 429/460/514)

1970–1982 335/Cleveland V8— small-block (351 Cleveland/400/351M/Boss 351

1972–1985 Ford Australia produced Cleveland V8 engines 302/351 (Geelong plant)

At this current state I wish Ford would have LS style SBF instead of the super wide 32v modular engines. Lucky though for us ’71-’73 enthusiast a 32v modular will squeeze between our stock shocktowers as seen here:

http://www.7173mustangs.com/thread-1972-mach-1-w-32-valve-cobra

Modular really benefits from the 4 valve per cylinder layout, it’s got a huge curtain areas and those stock blocks can handle up to 4.700” stroke. I was very impressed from the Jon Kaase’s and the Accufab built +400 cid 32 valve modulars for the Enginemasters 2013 competition. HP was pretty high for small n/a engine, now bring the compression down and add 14 lbs of boost and we are talking 4 digit hp numbers.

If you've got a big block in your old Ford, that's cool and I would keep it that way. If you don't, then unless you've got a raging compulsion towards big blocks, build an engine that's going to perform the way you want it to, regardless of whether it's an inline 6 or a turbo SBF.

I agree 100 % with you, we can use the straight 6, SVO V6, 4 cyl ecoboost, 302/351w/c, FE, 429/460, modular, even the V10 all these bastards can be fitted to our big ponies (not simultaneously but separately…) without a major modifications.

Here is a one way to full fill hp needs with 1971 Mach 1: