Close



Page 1 of 2 12 LastLast
Results 1 to 25 of 33
  1. #1

    Default Should i Twin-turbo my 1979 cobra with a v8?

    Random thoughts today, was wondering if anyone with some expertise had anything to say about this?
    1979 mustang cobra v8 302 4 barrel carb, 345 rear end
    My younger cousin was looking into buying his first car and looking at imports and said he could smoke my mustang and i replied saying i could beat anything if i had a twin-turbo which got me thinking if its actually reasonable or not to try this out.

  2. #2
    FEP Power Member
    Join Date
    Aug 2005
    Location
    Lancaster, ca
    Posts
    2,242

    Default

    If you can afford it and it's legal where you live, DO IT!

  3. #3

    Default

    Well I'm in Washington and I don't need to pass emissions since it's so old, and I am going to downgrade my current vehicle so I'm hoping to get around 2 grand extra!

  4. #4

    Default

    It would be wise, I think, to spend some of that budget on getting yourself a decent 302, like and Explorer motor, to start with. They are common and cheap, and breathe way better than a '79 302.
    Brad

    '79 Mercury Zephyr ES 5.0L GT40 EFI, T-5
    '17 Ford Focus ST
    '14 Ford Fusion SE Manual

  5. #5

    Default

    That sounds like a good idea to me! But going down that logic path, Should I then just buy a cheap 4 banger for body and swap the engine and turbo that instead of the cobra? My cobra is still pretty much all original except for a bigger carb and straight-pipe exhaust.

  6. #6
    FEP Senior Member rob342's Avatar
    Join Date
    Aug 2014
    Location
    darien, il
    Posts
    522

    Default

    when i bought my 92GT, it was bone stock with a 4.10 and a little baby powerdyne blower. i had no traction in 1st, 2nd, and 3rd was "iffy". 4th was ok. if you add power you'll end up modding a lot more than the engine if you plan to beat anything. keep that in your mind/budget.
    i have a 1992 GT, 4.10, 5spd.

  7. #7

    Default

    Yeah the thing is that this was my daily driver since I bought it and I didn't want to do much to it since it was original and I thought it would be worth something but I got another car and threw the mustang on craigslist and got no bites so I'm kinda just feeling screw it, let's make a race car instead.... So I'm up for spending a bit to make this pretty fast

  8. #8
    FEP Super Member Travis T's Avatar
    Join Date
    Jan 2011
    Location
    China Grove, North Carolina
    Posts
    5,267

    Default

    If your Cobra has a four barrel, it's been modified a little bit at least. 3.45 gear, that means you still have the 7.5 rear axle which you'd need to replace. You'd end up swapping the entire driveline out of your Cobra so I wouldn't bother if it's in good condition.
    1984 Mustang GT owned since 1991 (first car). Mercury Mountaineer GT-40P engine, some suspension mods, currently undergoing a five lug SN95 brake upgrade and more suspension mods. Some minor body and interior mods have been done as well.

    2004 GT convertible, 2001 Taurus LX, 1994 F150, 1950 F-1 Ford Pickup

  9. #9
    FEP Super Member onetrackrider's Avatar
    Join Date
    Apr 2009
    Location
    Denver, Colorado
    Posts
    4,660

    Default

    pic's of said Cobra please..
    Current rides:
    89 LX 5.0, 5 -spd..the Lemon
    86 RS Capri 5.0 Auto...
    86 LX Colorado SSP 5.0 5-spd (Sadly Sold)
    85.5 SVO, Finally Got Boost
    83 RS Capri 5.0, 5-spd (another sadly sold)

  10. #10

    Default

    If it were me, I would modify it. If nothing else, when you drop the Explorer motor in, you can set your matching number 302 aside and keep it as is in case you want to go back to original. Again if it were me though, I would just dump it. Any engine made for a '79 model car was a turd. I think even just swapping engines will make you VERY happy.
    Brad

    '79 Mercury Zephyr ES 5.0L GT40 EFI, T-5
    '17 Ford Focus ST
    '14 Ford Fusion SE Manual

  11. #11

    Default

    If it's the original 3.45:1 rearend, then maybe the car wasn't built with the 302/5.0.

    What are the first five characters of the V.I.N?
    '88 Mustang GT convertible, T5, 3.08:1 gears. 5.0 Explobra Jet: A9L Mass Air conversion, Fenderwell Mac cold air intake, 70mm MAF meter = 4.6 T-Bird/Cougar housing + '95 Mustang F2VF-12B579-A1A sensor, aftermarket 70mm throttle body and spacer, Explorer intakes, GT40P heads with Alex's Parts springs and drilled for thermactor, Crane F3ZE-6529-AB 1.7 "Cobra" roller rockers, Ford Racing P50 headers, Mac H-pipe, Magnaflow catback, Walbro 190 LPH fuel pump, UPR firewall adjuster and quadrant with Ford OEM cable, 3G conversion ('95 Mustang V6), Taurus fan, rolled on Rustoleum gloss white paint...
    Past Four Eyes: Red well optioned '82 GT 5.0, Black T-top '81 Capri Black Magic 3.3L 4 speed, Black T-top '84 Capri RS 5.0 5 speed.Over 200,000 miles driven in Four Eyes, and over 350,000 in Fox Body cars.

  12. #12
    FEP Power Member
    Join Date
    Jan 2014
    Location
    Arlington, Texas.
    Posts
    1,016

    Default

    The drivetrain you would have to put in it for what you are asking it to do would be more than what the car is worth. For traction you would have to tub the wheel wells with a narrowed rear end. Not to mention a full roll cage set up. A twin turbo set up would also mean the 302 block would not be able to handle that kind of power for very long. 500 HP max is about far as you can go. I'd just go buy 4 eyed race car and do what it takes to make it street legal. Much cheaper.

  13. #13
    FEP Super Member Travis T's Avatar
    Join Date
    Jan 2011
    Location
    China Grove, North Carolina
    Posts
    5,267

    Default

    Quote Originally Posted by grabbergreen84 View Post
    If it's the original 3.45:1 rearend, then maybe the car wasn't built with the 302/5.0.

    What are the first five characters of the V.I.N?

    That is a good point - only the 2.3 turbo came with that gear.
    1984 Mustang GT owned since 1991 (first car). Mercury Mountaineer GT-40P engine, some suspension mods, currently undergoing a five lug SN95 brake upgrade and more suspension mods. Some minor body and interior mods have been done as well.

    2004 GT convertible, 2001 Taurus LX, 1994 F150, 1950 F-1 Ford Pickup

  14. #14
    Venomous Moderator Hissing Cobra's Avatar
    Join Date
    May 2002
    Location
    Wareham, Massachusetts
    Posts
    9,720

    Default

    It's not just the motor that you have to build. You have to have a great ignition, exhaust, cooling system, transmission, rearend, and suspension. Slapping a turbo on a 302 sounds like an easy thing to do but there's a whole lot of other things that need to be addressed and none of it is cheap. What you're proposing sounds great but it's going to cost you at least $10,000 or more just to get the drivetrain right so that everything can handle that kind of power.
    Pete Slaney

    1979 Mustang Cobra

    347/T-5/4.30's
    420 rwhp/380 rwt (New Motor)
    11.49 @ 121.86

    306/T-5/4.30's (Old Motor)
    307 rwhp/278 rwt
    12.38 @ 111.38

  15. #15
    FEP Super Member Ken P's Avatar
    Join Date
    Jun 2005
    Location
    Woodstock, Georgia
    Posts
    3,213

    Default

    A lot of good points here. One thing to consider is doing only a single turbo instead a twin set-up. A whole lot less plumbing and easier to tune. If you go twin turbo and then over boost on only one side it can blow the motor in half so to speak.

    A turbo is fun but can be quite expensive.
    86 LX Coupe 4E
    84 SVO Watkins Glen Pace Car 1E
    85 SVO Hertz 4E
    85.5 SVO 2R orig owner
    86 SVO 7B
    66 Fastback
    55 Willys Jeep Overland Wagon

  16. #16

    Default

    I leave for work and all these replies happen! So here's more info on car https://seattle.craigslist.org/see/cto/5080729494.html thats about everything to do with it.
    I'm really only looking to spend like 3 grand on the thing, less preferable

  17. #17

    Default



    Nice Cobra! I love that color.
    '88 Mustang GT convertible, T5, 3.08:1 gears. 5.0 Explobra Jet: A9L Mass Air conversion, Fenderwell Mac cold air intake, 70mm MAF meter = 4.6 T-Bird/Cougar housing + '95 Mustang F2VF-12B579-A1A sensor, aftermarket 70mm throttle body and spacer, Explorer intakes, GT40P heads with Alex's Parts springs and drilled for thermactor, Crane F3ZE-6529-AB 1.7 "Cobra" roller rockers, Ford Racing P50 headers, Mac H-pipe, Magnaflow catback, Walbro 190 LPH fuel pump, UPR firewall adjuster and quadrant with Ford OEM cable, 3G conversion ('95 Mustang V6), Taurus fan, rolled on Rustoleum gloss white paint...
    Past Four Eyes: Red well optioned '82 GT 5.0, Black T-top '81 Capri Black Magic 3.3L 4 speed, Black T-top '84 Capri RS 5.0 5 speed.Over 200,000 miles driven in Four Eyes, and over 350,000 in Fox Body cars.

  18. #18
    FEP Super Member xctasy's Avatar
    Join Date
    Jun 2012
    Location
    Dunedin 9011, New Zealand, South Pacific
    Posts
    3,961

    Default

    NEB

    Not Enough Budget.

    The turbo or turbos have to be perfectly sized, and managed ofr fuel delivery. EFI, stroker don't feature for you, but managing a turbo via carb is harder as the engine has to cope with charge density variation, inter/after cooling. Compression ratio, cam, igntion, everything has to work, axle capacity (you can't use a 7.5 without fear of it breaking, you wouldn't use 3.45's, you would have to consider end use regarding the gearbox type, the block isnt stallar for strength, and if you mess up on any aspects of the carb, turbo sizing or fabrication, it'll roast your every quarter your bank has every time you explore the delights of the abdiatic turbo cycles.


    Here is how to put a single turbo on a 342, which is a factory 1998 onwards Explorer/Mountaineer 5.0 block with a factory crank girdle and cast crank, Argo rods, Mahale pistons (originally).

    This is from the Aussie Ford Forums.


    It is repeated here, with only the turbo pictures (images 6 to 12) shown.

    http://www.fordforums.com.au/showthr...1388934&page=2


    Quote Originally Posted by XH5LWEPN View Post
    We have confirmation. Myself and Dave (BOTTLEDUP) spent the last hour stripping the rest of the engine and inspecting.
    Pretty happy with what we found!
    Pistons are SRP Forged 4.030" with 12.5cc dished top, P/N-151868.
    Rods are the original Argo I-Beams.
    Crank is the standard T3 cast item.
    Tickford mains girdle is still present.
    Camshaft was the std item with "T3" stamped into it.
    Timing Chain was Rollmaster.
    Head Gaskets appear to be Cometics at around .040".
    Valve Springs and retainers we are thinking Isky's.

    So all in all it all looks good. Doesnt look like its done alot of work in its current combination. Hone marks are still very apparent on the bores.
    Good thing the standard pistons are gone and the SRP's are in with more room for bigger valves . Would go nice with a set of AFR185's on it, but at this stage im not pulling the heads, because both myself and Dave, or anyone else that knows me, knows that if the GT40P's come off, theres no way theyre going back on

    Anyway, enough chat, heres some pics.

    Before we pulled sump.
    image1

    Sump off and we like what we see.
    image2

    Argo Rods with cap studs, Tickford engineered girdle
    image3

    Mmmm....SRP goodies!!
    image4

    Rollmaster Set.
    image5

    Heres a couple of shots of the manifolds, dump pipe, wastegate and turbo for those interested.

    Aussie Drivers side (US Passenger Side).
    image6




    Aussie Drivers side (US Passenger Side) adaptor to LS1 flange.
    image7



    Aussie Passenger side (US DriversSide)with T4 flange and merge.
    image8



    Dump Pipe, 3" with wastegate plumb-back pipe.
    image9



    Turbonetics 35mm 2-bolt External Wastegate.
    image10



    Turbonetics T-66 Turbo.
    image11



    Intake pipe.
    image12



    And finally this is how #149 sits tonight!!
    image13

    image14


  19. #19
    FEP Super Member xctasy's Avatar
    Join Date
    Jun 2012
    Location
    Dunedin 9011, New Zealand, South Pacific
    Posts
    3,961

    Default

    The kind of turbo was too small, but it fits the passenger side battery of the pre EFI Mustangs, and would package okay if you used the EFI coolant recovery bottle.

    Turbonetics T-66 Bush Bearing turbo, (but it had a tiny 0.58 rear housing ) and a Turbonetics 35mm 2-bolt flanged wastegate. Stainless Log manifolds with 2.5" crossover with flex joint. T4 Flange, plumb back wastegate into 3" dump pipe.

    3" dump pipe leads into 1 aftermarket cat then splits into a twin 2.25" exhaust which is press bent in mild steel with two 3.5" straight cut tips.

    No inter/aftercooler.




    Right hand exhaust




    Its a little dark in the Aussie Falcon engine bay, but the later Explorer, GT40 and Trickflow intake upper is reversable, so you can run the crome intake line to a bigger throttle body for EFI. or put an early Paxton supercharger carby 'hat' cover over a 4180C or 650 double pumper with a proper Edelbrock 4-bbl intake, and run a boost bonnet/hat.





    Then I'd look for an intercooler from the turbo to the carb box.

    Dolla's are your limit to Automotive Nivarna...


    Wish you the best!

  20. #20

    Default

    Drop a mildly worked over 460, and enjoy mountains of torque for little cash.

    Jess
    Previously owned;
    1979 Mustang, v6 swapped to EFI 393, custom installed m122 blower, 4r70w trans, Megasquirt II, T-top swaped in.
    1990 Mustang, 545 BBF, C-4 with brake, ladder bars.
    1983 Mustang, 1984 SVO Mustang
    1984 Mustang convertible, v6 swapped to 351
    1986 Mustang GT, 1989 Mustang GT convertible
    1992 Mustang coupe, 4 swapped to 302

  21. #21
    FEP Super Member xctasy's Avatar
    Join Date
    Jun 2012
    Location
    Dunedin 9011, New Zealand, South Pacific
    Posts
    3,961

    Default

    Turbo Lag? Aint nobody got time fo that. LOL

    Depends where you are and what you are doing. Jess has the engine swap background to help out. If I had 3 k, I'd personally swap to a taller 351M and turbo it. A single turbo is very cheap. Twin turbo on Budget.... bad idea.

    Engine swaps can save you money, because the bigger Ford engines come with much better gearboxes, axles and are potentially more reliable bases. Look at mustangxtreme's 1981 Black Magic 400 c6.


    See http://vb.foureyedpride.com/showthre...4637-400M-swap
    http://vb.foureyedpride.com/showthre...2-Long-rod-351

    See how simple a turbo is on a small 87 hp B code 1983 six in line. http://fordsix.com/forum/viewtopic.php?f=99&t=24859


    Now, the reasoning...

    1. In most states, a truck engine swap isn't lega, but truck type engines from passenger cars are better bases to turbo. Turbos break things, ESPECIALLY ON A SHOE STRING BUDGET.

    2. As said, If I had 3 k, I'd personally swap to a taller 351M, and that's an engine that has the best "factor of safety" of any Ford V8 this side of a good FE. You could find a legal 79 H code 351 Windsor or the really heavy duty Q VIN no 351 for very little.The 460 is a truley Fords most excellent engine, it can soak up any modification and doesn't need forged pistons or a lot of prep work.


    If you were turboing something with a carb, you don't want it to be a Windsor F code with its poor bore quality, unless you konock the compression down, or use a propane conversion to avoid detonation.

    The issue is that a canted valve engine was a legal swap for a 1979...the non CA Q code 351M was last offered in T-birds in 1979, so find a Tbird, and swap in one with a 351C swap kit. It was just a 151 hp 8:1 compression engine, but it had the five link morse timing chain, uprated main bearing caps, long rods with very good rod ratios which stop the bore and block splitting woes of the 302 and all other 335 engines. In terms of potential, the 351M is sensational for a turbo base.

    A 460, well, it aint strictly legal....

    For an 800 dollar kit, and a good later model 351m (the best blocks were the toploader capable 1978-1982 Bronco and truck ones, but any post 1977 one will do), you could turbo it...they are very, very strong engines, hugely underrated, but still not as good as a 460. As a turbo engine, it wold last a long time though.


    Issue is that the front distributor M's and Big Blocks are very tall...you have to look at 4 or even six inch hoods to cover them, the 351m and 400 small blocks are as tall as the 429/460 big blocks, and insanely heavy. For the 60 cubes on the table between the 460 and 400, and 90 between the 460 and 351, you'll be adding big block weight, with small block capacity.

  22. #22

    Default

    XC, have you ever made a short post? I think you need to ship me one of those late '90s 302 Falcons though.
    Brad

    '79 Mercury Zephyr ES 5.0L GT40 EFI, T-5
    '17 Ford Focus ST
    '14 Ford Fusion SE Manual

  23. #23
    FEP Super Member xctasy's Avatar
    Join Date
    Jun 2012
    Location
    Dunedin 9011, New Zealand, South Pacific
    Posts
    3,961

    Default

    I've done the odd sort post. Just not this one.


    With just a junkyard 351w roller capable turck engine and EFI, you can hit 1054 hp with just a single turbo

    http://www.mustangandfords.com/how-t...-past-1000-hp/


    That's the not hell for strong F150 truck engine. The best other production junkyard 351 engine? The Q code 351M OR S code 400 Ford small block.

    IMHO, the best engine ever production block engine is the SVO based Windsor-Cleveland style 9, 9.2 and 9.5" deck Roush Yates RY45/ F452. It carried conventional Windsor 351 and Cleveland 351 hallmarks with 8 bolt valve cover Boss 302/Boss 351 alloy heads in NASCAR legal and illegal form before the more cost effective 2007 FR9 Wolfe engine got ushered in. (Having to do a fortnights worth of maching to a loosely production block since the advent of the SVO/FRP block was no the the way Forward).

    Normally, any production thinwall SBF Henry block is a bore splitting, block cracking, main bearing scouring, con rod breaking risk, and going canted valve increases the loads on the block fourfold. The 10.320" tall 400 and 351M engines started off pretty poorly, but the evolutionary casting changes made it a really good production 335 series engine, probably the best factory 335 engine, with the 351C 4V absolutely the worst. The 385 series 370/429/460 engines eliminated all the worry, its based on the MEL Lima 462 engine, and is the only Ford engine that folows the FE's Total Performance ideal of not being afraid to put some metal between the cylinder bores...it is better still than any SBF, but its getting too big, and just an extra 100 foot pounds makes it too torquey for a Fox.

    Any of the HP289/302/351/400 engines with the more TransAm/NASCAR or Australian Vee Eight Super Car Organization (AVESCO) blocks (thicker castings which copied the ASK, SK or XE cast Ford racing blocks used in TransAm, Group C, and NASCAR) will also love turbo charging if the compression is low enough. That's why the last junker 351M and 400's are so darn good. Just compact enough to fit a Fox, and almost strong enough to resist a nuclear attack. They are the only stock engines small enough to be boosted without breaking, and rev hard enough without taking the whole Fox structure out.

    That's my take on it. Other less kind people say the 351M and 400's were almost as good as the best stock AMC, Mopar, Caddilac, Pontiac, Oldsmobile , Buick, and Chevy blocks, which is very unkind, but kinda true.


    Research the post 1977 model year long rod Q code 351M and S code 400 tall deck engines, how easy they are to mount, how easy they are to get.


    If you going to turbo it, you won't need tube headers you can use the truck or passenger 351M/400 or even 351C cast iron headers and fabricate a single turbo on the passenger or drivers side. The passneger side headers were all the same, but the drivers side headers for some trucks and vans varied. So if you swapped the headers left for right, there are two types of forward facing headers to chose from, meaning the turbo conversion is really easy to do.


    If your battling a dollar limit, I can't see how a Q code 351M wouldn't give you
    1. the best gearbox (Big Block 6 bolt bellhousing and 351m/400 180 teeth External, 24 oz. imbalance flywheel, or 370/429/460 4 speed top loader 176 teeth or 184 teeth External, 24 oz. imbalance flywheel, or C6 flexplate). A Toploader or C6, you won't easily break...
    2. The best rod ratio
    3. The deepest piston ring set...the 351M piston compression height is 1.947", perfect for a turbo.
    4. The biggest small block wrist pin
    5. The best block, no oval cast egg shell cylinder bores, the bores come in way over 130 thou thick even after a 30 thou overbore
    6. The lowest compression heads and pistons
    7. The easiest fit to a hood scooped Fox body
    8. You can go up to 400 with just crank and piston changes if you must.
    9. With a good stock block rehoned, you can use the TRW L2466F piston, an insanely tough piston.
    10. The stock van sump and be cut up, you don't even have to save up for a Kevko, Mildon, or Moroso sump.
    11. Any 4-bbl Cleveland intake fits it with some 1.1" alloy spacers (Edelbrock Performer RPM Air Gap 351C intake)


    And look how nice it sits...



  24. #24

    Default

    You will never convince me that a 351m is a better choice than a 351w or 460.

    Jess
    Previously owned;
    1979 Mustang, v6 swapped to EFI 393, custom installed m122 blower, 4r70w trans, Megasquirt II, T-top swaped in.
    1990 Mustang, 545 BBF, C-4 with brake, ladder bars.
    1983 Mustang, 1984 SVO Mustang
    1984 Mustang convertible, v6 swapped to 351
    1986 Mustang GT, 1989 Mustang GT convertible
    1992 Mustang coupe, 4 swapped to 302

  25. #25
    FEP Super Member xctasy's Avatar
    Join Date
    Jun 2012
    Location
    Dunedin 9011, New Zealand, South Pacific
    Posts
    3,961

    Default

    Quote Originally Posted by Mustang-junky View Post
    You will never convince me that a 351m is a better choice than a 351w or 460.

    Jess

    I don't have to. Its about hp per dolar without breaking parts. That often forces you to play hopscotch. Racing is real, anything else is just a game...

    Boat, F1 and stock block V8 people have been destroking engine blocks for turbo engines just so that they survive. In 1988, an article by Bob Matic and Brad Gridwood showed the Aussie Bensons twin turbo 302 Cleveland boat engine was destroked 351C, so its block would survive under 1000 hp endurance conditions. It had four bored out CDS175 carbs from a formerly 268 hp 5.3 liter Jag V12, Duraspark, and very little else. It was designed to beat everything else supercharged, and it took out big blocks becasue it could survive.

    So was the #702 1984 25 Turbo engine, also seen on the 1985 -86 200 hp A310 Renault PRV Turbo engine, they took it down from 2849 cc to 2458 cc PRV Z7U #730 turbo V6 just to let the block survie. The smaller V6 2458 engine B25ET was found in a few Volvo 780's.

    Same with the 1978 Le Mans A442B, a 2.0 liter engine IIRC, the bigger 2.138 liter A443 engine didnt survive. Destroking or optimizing the pistons to stroke package is generally a crutch, but there are times when it allows an engine block to avoid detonation damage. I cite the

    1.302C twin turbo,
    2 and 3 the two French engines,
    4.the 351M,
    5.the 1966 Repco F1,
    6. the 304 Holden 1995 AVESCO engine by Larry Perkins,
    7.the 1968 style Z28 302 used in AVESCO,
    8. the Honda's mid year revison 1993 engine (cant remember exactly, but the redid the whole engine to suit the Shell fuel)



    In drag racing or on the street, a bigger hammer stomps a small spider. But if its dollars per pound of boost, a Chinese Turbo and a well supported small block 351m will trump anything else. I can't tink of any Ford engine that has a better block for the scap metal value, or an engine less understood than that engine.

    A 460 is Fords best engine, but in most cases unless your a really good driver, the Big Block is just too big and virile for the Fox chassis, and, all else being equal, the 351W is unable to make the power or a 335 headed engine, but has a less detonation prone head design. The 351M has traded off bore spacing for better block dynamics for a turbo engine. Fro what I've learned, Ford got everything right on that little engine. If I turboed the 351m the same way the 351w was in that 1054 hp engine combination, I'm certain the 1.88 verse 1.696 rod ratio would have given a comparable cfm per lift head on a 351M 5% more power, and lots more revs, with the same boost. Ford made the 351m for a purpose. It was the first substaintial detonation resistant 335 engine, which learned the lessons of the terriable block vibrating 351C's bore splitting ways.

    The point is that any turbocharged engine has to be supported by its block and rods. When you trade off rod ratio (conrod length verses stroke) against bore: stroke and total piston area, you find that there is a five point interplay on a turbocharged engine. Honda in 1993 used this when the fuel regulations weren't policed as well as they should have been, and designed a whole engine around detonation resistance, playing off critical engine loads against fuel quality. They optimized three or four of the below engine factors, and came away with a win. So did the 1966 F1 wining engine. So did GM Holden with the AVESCO 304 Holden, and then the 302 Chevy engine for many years.


    1. the biggest bore spacing verses capacity wins (meaning a Big Block 460 wins everything)
    2. The lowest L/R ratio means you can lean on the engine more without detonation. (meaning a Big Block is a little more restricted than a 351M or an F1 engine)
    3. the most biased to bore: stroke ratio is the one that allows best boost (the Big block wins)
    4. the piston deck height and ring spacing must allow the best compromise between high speed dynamics and leakdown (the Big Block starts to loose out, the dpea piston Z28 Chev 302 or 215 bop/2.5 liter Repco Brabham based engines had superior ability to avoid ring spark at speed).
    5. When turbocharged, Honda attempted to vary the above four to suit fuel and make the engine more powerful. When unturbocharged, the Repco, Holden and Chevy formula engines were optimized to suit.


    Phil Irving's 1966 F1 winning single OHC engine won Gran Prix races because of 40 years of engine design experience, not because it had better cfm figures than the oposition. It did so with a
    (1) very big bore centre spacing for its capacity for endurance cooling,
    (2) the lowest ever L/R ratio .(Daimler SP250 conrods with a super short crank throw).
    (3) the most biased bore to stroke ratio
    (4) the tall piston was gentle to the block
    (5) it wasn't turbo charged, but the engineer varied the top four to make up for a lack of quad cams .

    Up untill Project Blue Print scaled back the 9" deck Chevy block with its 1.9" potential deck height verses the Fords 1.647" piston deck and shorter rods, Ford in Australia lost races against the tall deck 302 Chevy engine for years because the engine package was better at detonation resistance than the short deck Boss 302 based A3 engine. Effectively, the Chevy engine had to be hobbled back for Ford to win!


    Engine masters also play off these, but if its just peak power, it only has to hold together to a certain percentage of critical recipricating load, so they play with long stroke, short deck engines.

    Best example is David Vizards play off of stock engine blocks in 1435 and 1559 cc sizes, with measurment of frictional horsepower losses. When Morse tests were done, the total power and specific power of the long stroke 1559 A series engine was counter productive to engine longiveity. He remarked that, all esle being equal, a good driver would always make the engine with the biggest capacity engine a winner, but that the smaller engine would last longer. He defined exactly what happens to maximum power as the rod L/R ratio was lowered.


    Shove the 351W, 351M, 460 basics in any engine in the Engine Analyser program, and you see the same thing. How many dollars to keep the engine block under critical maximum loads. The 351m has the cooling, block, rods, piston and crank to cope with a lot of boost.


    PS. Oh yeah. Read the optimisation tradeoffs between engines here. It covers most of what I'm on about. http://www.epi-eng.com/piston_engine..._cup_to_f1.htm

    PSS. Because I'm a drag racer at heart. Brian Dean/ Cole Cutler/ Greg Everitt 34's with Big Blocks, yeah!




    Cole Cutler sold it to a guy who is now twin turboing it, for a while had a destroked Mopar 440 six pac rod Big Block 429 Shot Gun headed 460 engine in his 34, it is my favorite engine ever. I'm not saying the 460 block isn't the best, just that there are other ways to cheat the dolllars verses horsepower equation, especially when an engine is detonation limited. That's afterall what a EcoBoost is...a detonation limited small turbo engine

Page 1 of 2 12 LastLast

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •