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ats4x4dotcom wrote:As for a "revvy" small block, still no match for a big block in the all round stakes, and a 850 Q jet carby off a buick 455 is a better unit to set up for off road use, with small primaries for good signal down low in the RPM, and you can fit parts which prevent fuel splashing over in rough stuff as well. [been there done that]
Holley isnt worth the effort, wiull never run right off road.
I am going to drop in and have a chat for sure, interested to learn more about the above set up. Thanks for the help!
just run straight gas man.
dont waste your money on fuel injection!!!!
run msd 6al for ignition ( or DIS for more $$) and twin impco 425's ontop of a spreadbore throttleplate. ( single plane alloy manifold)
you can play with a tunnelram and twin squarebore baseplates but you wont have as much low down torque as a single throttleplate dual mixer setup.
cheers,m
Jes
One small problem, its hard to get gas on a station in the middle of the outback, has to be petrol. Thanks for the suggestion tho jessie.
your gona take a 454bb equipped truck running on petrol into the outback? get ready for a MEAN MEAN fuel bill
in any case its easily solved by fitting an entire carb under the impco 425's instead of just the baseplate . No electronics, basic setup, ultra reliable.
Jes
Mine would return 16 lt per 100km hwy on 36" swampers, and driving it hard would use no less than an old TB 42 or turbo TB 42, really.
When the car will go harder, without using as much pedal, you will use less fuel, simple.
Too heavy, will break C/V s and steer poorly, too much wheight over the front axle, if you can afford it but an L76 6.0L and stroke it to 402 with a mild cam and it would be more powerful, lighter and more economical.
PGS 4WD wrote:Too heavy, will break C/V s and steer poorly, too much wheight over the front axle, if you can afford it but an L76 6.0L and stroke it to 402 with a mild cam and it would be more powerful, lighter and more economical.
Joel
set of cal offroad CVs ... problem fixed
BB ALL THE WAY!!!!
if you don't want it i'll have it!
H( * )( * )NZ loves B( * )( * )BIES
if a fat lady falls in the forest do the trees laugh?
[quote="RUFF"]although i didnt mean to, i squealed like a girl :armsup:[/quote]
PGS 4WD wrote:Too heavy, will break C/V s and steer poorly, too much wheight over the front axle, if you can afford it but an L76 6.0L and stroke it to 402 with a mild cam and it would be more powerful, lighter and more economical.
Joel
Why would you buy an L76 when they only came in one model here?
As you can dee from previous posts if you bothered to read them, a big block will be lighter than the engine coming out, with alloy inlet, extractors etc, and even more so if it has alloy heads.......
As for broken cv's, drivers break them, not engines, the right grease makes allot of difference, with the right cv's.
The L76 is the incoming engine in this country, the L98 current commodore engine is the same compression, cam, heads but without the Active fuel management (the ability to kill 4 cylinders for economy) There will be a variable cam version available soon. There would be 80 kg difference in weight, why have the heavier engine? More likely to bend diffs, need stronger springs, steering will be heavier and you can make a Gen 4 motor up to 480 CI anyhow. Not to mention an L76 is $4000 in stock form. Big blocks are great, but when you can get more power for less weight why wouldnt you.
Whats a 454 or 502 with alloy heads worth? Not to mention they are physically bigger making installation more challenging.
PGS 4WD wrote:The L76 is the incoming engine in this country, the L98 current commodore engine is the same compression, cam, heads but without the Active fuel management (the ability to kill 4 cylinders for economy) There will be a variable cam version available soon. There would be 80 kg difference in weight, why have the heavier engine? More likely to bend diffs, need stronger springs, steering will be heavier and you can make a Gen 4 motor up to 480 CI anyhow. Not to mention an L76 is $4000 in stock form. Big blocks are great, but when you can get more power for less weight why wouldnt you.
Whats a 454 or 502 with alloy heads worth? Not to mention they are physically bigger making installation more challenging.
Joel
But the L76 which was in the last model designation commodore, isnt at a good price, and to make it 480ci would make his wallet 80kg lighter also.
Much easier, and cheaper to run an engine that doesnt cost a squillion on rebuilds, or replacing expensive aftermarket parts that made it a stroker, in the 4wd sport, because you can never be 100% sure it wont get a dirt water or dust ingestion.
A gen engined 4wd requires much $ and work, to mkae the low down torque, and power required, or that a big block delivers.
$4000 makes for a good performing big block, inc purchase price, a gen engine will always be double the cost minimum for the same power/torque.
you don't need to run a mass of wires and a computer to run the BB
454 parts are fairly easy to get hold of
BB are easier to rebuild
CI is already there!
mass lowdown torque
H( * )( * )NZ loves B( * )( * )BIES
if a fat lady falls in the forest do the trees laugh?
[quote="RUFF"]although i didnt mean to, i squealed like a girl :armsup:[/quote]
As you know Paul I'm no mechanic or expert 4wd'er but I'm just thinking of the time constraints with what you have got on your plate already. Seeing you're yet to have a drive with the navi, get the engine if you must, but just hold off on the conversion so turbogu has a chance to talk you out of it before Cliffhanger!
Jump on the COME site, big cube gen 3/4 are not that dear, strocker kits are cheap these days, eveyone sells em. I like technology, never said a big block wouldnt be good, just the power to weight of a gen3/4 is better. Alloy heads dissapate heat better, less prone to detonation. And the LS1 ecu is hard to beat, better than anything aftermarket for accuracy.
Every pound makes a difference.
You will no doubt produce power and heaps of good usable torque, but at the expense of added extra weight compared to other options.
You will need to go down the alloy block path if you have any hope of a standout truck.
Just remember the bit about momentum and inertia ........
As you hit the contour bank , the weight up front will have to overcome inertia which will do every thing it can to drive straight through the bank and make the suspension work overtime and excessively , and then when it finally gives in and jumps the bank, it will then have momentum problems and try to burry itself on re-entry.
If you are going to take the BB path, make it light......
It is possible if you are prepared to spend up on aftermarket components.
PGS 4WD wrote:Jump on the COME site, big cube gen 3/4 are not that dear, strocker kits are cheap these days, eveyone sells em. I like technology, never said a big block wouldnt be good, just the power to weight of a gen3/4 is better. Alloy heads dissapate heat better, less prone to detonation. And the LS1 ecu is hard to beat, better than anything aftermarket for accuracy.
Joel
But if pre detonation isnt an issue now, why would it be when the cooling system works?
As for weight, I overcame that issue easy, I moved the motor, gearbox, and transfer case backward in my truck, and centre mounting the winch can make a massive saving in front end weight.
As can going to a suspension set up designed to cope with the intended purpose, if someone wants to build a serious truck.
Here is some good info on the various models of the BB.
I have a 502 and a 496, both over the counter imports from the US, I recon they are both good engines, but if you are really serious I would be inclined to go with the smaller ZL1 Alloy Block engine as its a great performer right out of the box.......
The Mark IV aluminum big block, first used in the 1969 427 "ZL1", was reintroduced in 1997.
Anyway here is the info that will let you know all the various changes as they evolved.
Mark I: The original "Big Block Chevy", also called the "W" engine perhaps because of the layout of the valves and therefore the shape of the valve covers--although another possibility is that GM chose the "W" prototype for production rather than the competing "X" or "Y" prototypes, and therefore it's a convenient coincidence that the valve layout is in the shape of a "W". It should be noted that this engine became "Mark I" only after the Mark II was being designed years after the "W" was introduced. Whatever the origin of the name, this engine family was installed in vehicles beginning in 1958, as a 348. In 1961, it went to 409 cubic inches, (as immortalized in the Beach Boys song "She's so fine, my 409") and for one year only (1963) a few well-connected racers could buy a car with a 427 cubic inch version called the Z-11. The 427 version was all about performance, and had special parts which were not directly interchangeable with the 348/409. While production of the 427 was severely limited, both the 348 and 409 were offered in passenger cars and light- and medium-duty trucks. The truck blocks were somewhat different from the passenger car blocks, having slightly different water jackets and of course, lower compression achieved by changes in the piston in addition to more machining of the top of the cylinder. A novel feature of this engine is that the top of the cylinders are not machined at a 90 degree angle to the bore centerline. The top of the cylinder block is machined at a 16 degree angle, and the cylinder head has almost no "combustion chamber" cast into it. The combustion chamber is the top wedge-shaped section of the cylinder. Ford also introduced an engine family like that in '58--the Mercury/Edsel/Lincoln "MEL" 383/410/430/462. The "W" engine ended it's automotive production life part way through the 1965 model year, when the 409 Mk I was superseded by the 396 Mk IV engine.
Mark II: This is more of a prototype than a production engine. It is the 1963-only "Mystery Engine" several of which ran the Daytona 500 race, and in fact won the 100-mile qualifier setting a new record. It is largely the result of engineering work by Dick Keinath. Produced mainly as a 427 but with a few 396 and 409 cubic inch versions, all in VERY limited numbers. Even though it was intended as a NASCAR-capable engine, it had 2-bolt main caps. This engine was never installed in a production-line vehicle by GM, it only went to racers. And even though it was available in 1963, it has very little resemblance to the 427 Mark I "W" engine of the same year. The Mark II was a "breakthrough" design using intake and exhaust valves that are tilted in two planes--a canted-valve cylinder head, nicknamed the "Semi-Hemi" or "Porcupine" because it is "almost" a hemi head, and the valve stems stick out of the head casting at seemingly random angles. The engine was the subject of an extensive article in the May, 1963 Hot Rod Magazine. Because of NASCAR politics, Chevrolet was forced to sell two 427 Mark II engines to Ford after the '63 Daytona race, (to "prove" that it was a production engine, and therefore eligible to race in NASCAR events) and so this engine is not only the grandfather of the Mark IV and later big block Chevies, it's also the grandfather of the canted-valve Ford engines: Boss 302, 351 Cleveland and variants, and the 429/460 big block Ford. The bore and stroke of the 427 MK II is not the same as the 427 MK IV.
Mark III: Never released for production. This was rumored to be the result of GM/Chevrolet's proposed buyout of the tooling and rights to the Packard V-8 engine of the mid-to-late '50's. The Packard engine was truly huge, having 5" bore centers. The former president of Packard wound up at Ford after Packard folded, perhaps because of that, Ford was also interested in this engine. Ford wanted to make a V-12 variant from it just as Packard had once envisioned. One way or another, neither GM nor Ford actually went forward with the purchase.
Mark IV: The engine that most people think of as the "big block Chevy". Released partway into the 1965 model year as a 396, superseding the older 409. It is a development of the Mark II and using similar but not identical canted valve (semi-hemi/porcupine) cylinder heads. It was later expanded to 402 (often still labeled as a 396, or even a 400,) a 427, a 454, and a few "special" engines were produced in the late '60's for offshore boat racing as a 482. There was a 366 and a 427 version that each had a .400 taller deck height to accommodate .400 taller pistons using four rings instead of the more usual three rings. These tall-deck engines were used only in medium-duty trucks (NOT in pickup trucks--think in terms of big farm trucks, garbage trucks, dump trucks, school busses, etc.) The tall-deck blocks all had 4-bolt main caps, forged crankshafts, and the strongest of the 3/8 bolt connecting rods. All-out performance engines used 7/16 bolt connecting rods, along with other changes. This engine family was discontinued in 1990, with the Gen 5 appearing in 1991.
Gen 5: General Motors made substantial revisions to the Mark IV engine, and the result was christened "Gen 5" when it was released for the 1991 model year as a 454. There were 502 cu. in. versions, but never installed in a production vehicle, the 502s were over-the-parts-counter only. Changes to the Gen 5 as compared to the Mk IV included, but are not limited to: rear main seal (and therefore the crankshaft and block) were changed to accept a one-piece seal, oiling passages were moved, the mechanical fuel pump provisions were removed from the block casting, the machined boss for a clutch bracket was eliminated, the cylinder heads lost the ability to adjust the valve lash, and the coolant passages at the top of the cylinder block were revised. The changes to the coolant passage openings meant that installing Mk IV cylinder heads on a Gen 5 block could result in coolant seepage into the lifter valley. Frankly, the changes (except for the one-piece rear main seal) were all easily recognized as cost-cutting measures which also removed some quality and/or utility. All told, the Gen 5 engine was not well regarded by the Chevy enthusiasts because of the changes to the coolant passages and the lack of an adjustable valvetrain. As always, the aftermarket has provided reasonable fixes for the problems. The Gen 5 lasted only until 1995.
Gen 6: GM recognized that it did not make any friends when it designed the Gen 5, and so they chose to revise the coolant passages again when designing the Gen 6, allowing the older heads to be used without coolant seepage problems. The boss for the clutch bracket returned, but was generally not drilled and tapped. The non-adjustable valvetrain remained, as did the one-piece rear main seal. Some but not all Gen 6 454 (and not 502) blocks regained a mechanical fuel pump provision. Production engines installed in pickup trucks got a high-efficiency cylinder head, still canted-valve, but with a modern heart-shaped combustion chamber of about 100cc. The intake port has a "ski jump" cast into it to promote swirling of the intake air flow. All production vehicles with a Gen 6 used a 454 version, but over-the-counter 502s are available. The Gen 6 is sometimes referred to as the "Gen Fix" because it fixed a number of issues that disappointed enthusiasts when the Gen 5 was released. As an added bonus, most if not all Gen 6 engines use hydraulic roller lifters.
Gen 7: A very major revision of the previous engines resulted in the 8.1 liter/ 8100/ 496 cubic inch Gen 7 in 2001. The block gained .400 in deck height so it is the same height as the previous "Tall Deck" truck blocks, wider oil pan rails, and the cylinder heads have symmetrical port layouts instead of the previous 4 long/4 short port layout. Very little interchanges between the 8.1 liter engine and the previous Mark IV/Gen 5/Gen 6 engines. The head bolt pattern and even the firing order of the cylinders has been changed. There are some things that remained true to the previous Mk IV/Gen 5/Gen 6--the bellhousing bolt pattern, the side motor mount bolt pattern, the flywheel bolt pattern, and the exhaust manifold bolt pattern are the same. Note that the bolt holes are threaded for metric fasteners. The 8.1 is internally balanced, so you could install a flywheel/flexplate from a 396/427 Mk IV provided you use the correct bolts to suit the 8.1 crankshaft.
I have had a chance to compare Mark IV, Gen 5/6 and Gen 7 head gaskets. It seems to be possible--but very difficult--to install IV/5/6 heads on the Gen 7 block. GM did this on one show vehicle, it IS possible. You must move three head bolt holes in the block; and as the holes only move about 1/2 their diameter it would be difficult to plug the existing holes, re-drill the new holes, and still have enough strength in the deck surface. There are cooling system differences as well that must be addressed. I have NOT done this conversion; but I do have comparison photos of the head gaskets.
Specifications:
(sorry if this table loses it's formatting: I don't know how to fix it. It looks "ok" at full screen width on my computer)
Engine family Displacement Bore Stroke Rod length
MK I 348 4.125 3.25 6.135
MK I 409 4.31 3.5 6.010
MK I 427 4.31 3.65 6.135
MK II 427 4.31 3.65 6.135
MK IV 366 3.938 3.76 6.135 (Only offered as a medium duty truck engine)
MK IV 396 4.094 3.76 6.135
MK IV 402 4.125 3.76 6.135
MK IV 427 4.250 3.76 6.135 (Offered in passenger car and medium duty truck versions)
MK IV/Gen 5/6 454 4.250 4.0 6.135
MK IV 482 4.250 4.25 6.405 (very rare, made only for offshore boat races. Used tall-deck block)
Gen 5/6 502 4.466 4.0 6.135 (Over the parts-counter only; not installed in production vehicles)
Gen 7 496/8.1 4.25 4.37
Specials: GM has sold many special-purpose engines, partial engines, blocks, cylinder heads, etc., "over the parts counter" that were never installed in production line vehicles. It is very difficult to track all the various items--suffice to say that heavy-duty "Bowtie" blocks and cylinder heads in various configurations--Mark IV, Gen 5, etc, have been produced. Oldsmobile used the Big Block Chevy as a baseline when designing the first of the Drag Race Competition Engines (DRCE) so that the early DRCE engines have an Olds Rocket emblem cast into the block, but it's Chevy parts that fit inside. There are special high performance blocks and heads, in either iron or aluminum, produced by GM and by aftermarket suppliers to suit almost any racing need.
Coolant Routing Mk IV/Gen 5/Gen 6
There are two different ways that coolant can be routed through the engine: series flow and parallel flow. Both ways work just fine. There may be a slight preference for parallel flow, but it is not a big deal. Series flow has the water exiting the water pump, flowing through the block to the rear, it then transfers through the head gasket and into the cylinder head through two large passages on each cylinder bank at the rear of the block. The coolant then travels from the rear of the head, forward to the front of the head, into the intake manifold water passage and out past the thermostat and thermostat housing. The water cools the block first, then it cools the head. The coldest water (coming out of the water pump) is directly below the hottest water (having already picked up the heat of the block and the head) as the hot water transfers into the intake manifold. By contrast, parallel flow has the water exiting from the water pump into the block, where a portion "geysers" up into the head between the first and second cylinder, another portion "geysers" up to the head between the second and third cylinders, another portion geysers up to the head between the third and fourth cylinder, and the remainder transfers to the head at the rear of the block. The coolant temperature inside the engine is more even that way. The differences in coolant routing is having (or not having) the three additional coolant transfer holes in each block deck, and three matching holes in the head gasket. The heads have passages for either system, and are not different based on coolant flow.
Be aware that gaskets that DO have the three extra holes between the cylinders often have restricted coolant flow at the rear--instead of having two large coolant transfer holes at the rear, there is only one, and it's the smaller of the two holes that remains. This is important because if you use a parallel flow head gasket on a series flow block, you can have massive overheating and there's NOTHING that will cure the problem except to replace the head gaskets with ones that don't restrict flow at the rear of the block, or to drill the block decks to allow the coolant to flow into the head between the cylinders. Here's why they can overheat: A series-flow block doesn't have the openings between the cylinders, no coolant can flow up to the head there. The gasket may only have the single, smaller opening at the rear, so the amount of water that gets through that opening is greatly reduced from what the block designers intended. The result is that the coolant flow through the engine is only a fraction of what is needed.
Most, but NOT all Mk IV engines are Series Flow. ALL Gen 5 and Gen 6 engines are Parallel Flow. A series flow block can be converted to parallel flow by drilling 3 holes in each deck surface, and then use parallel flow head gaskets. You can use the parallel flow gaskets as templates for locating the additional holes. It's really easy: Put the parallel flow gaskets on the block, mark the location and size of the three extra holes. Remove the gasket. Grab a 1/2" drill and a drill bit of the correct size, and pop the extra holes in the block. There is NO modification needed on the head castings. Some blocks have one of the holes already, but it needs to be ground oblong to properly match the gasket. Again, very easy with a hand held die grinder and rotary file.
PGS 4WD wrote:Jump on the COME site, big cube gen 3/4 are not that dear, strocker kits are cheap these days, eveyone sells em. I like technology, never said a big block wouldnt be good, just the power to weight of a gen3/4 is better. Alloy heads dissapate heat better, less prone to detonation. And the LS1 ecu is hard to beat, better than anything aftermarket for accuracy.
Joel
But if pre detonation isnt an issue now, why would it be when the cooling system works?
As for weight, I overcame that issue easy, I moved the motor, gearbox, and transfer case backward in my truck, and centre mounting the winch can make a massive saving in front end weight.
As can going to a suspension set up designed to cope with the intended purpose, if someone wants to build a serious truck.
In short better heat dissapation means higher compressions can be used, meaning more torque, power and economy. Cast iron just dosent dissapate heat as efficiently, you can polish the chambers and perhaps HPC then and the exhaust ports. Anyone that welds alloy knows what I mean by heat dissapation.
I'm not knocing your truck, I've also moved the body and engine back on my LS1 turbo, the distribution is better but the cast iron is still heavier. Manufactures are just getting more power from late model high compression cast alloy motors, more uniform block and head temps mean the ability to run peak timing, it dosent detonate at hot spots, like small block chevys that knock on the middle cylinders due to the siamesed exhaust valves, LS1 went to even spacing valves which means more uniform temps throughout the heads. It's just manufacturers learning how to make better engines.
All the pre detionation isues I have seen on under 600 hp small and big blocks has been poor assembly, not radius edges, cheap gaskets, etc etc.
Anyone working on relliability for engine, and drivetrain for a comp truck isnt going to be pusing those HP limits, when torque is more important.
With the fuels at the pump today, you can run nice compression, massive timing, and cam advanced, and if assembled correctly, not have those issues, on a budget.
Sure, a newer engine will make easier power, but we are talking a GQ patrol, on a budget, and a cheap big block, and if working on a budget, the big block wins every time for power vs $.
If money werent an issue, the 427 crate motor with new pistons, and turbo would be in everyones truck.
If money were not an issue eveyone would have a 488 CI L7X World Block, higher decks, more head bolts, good for 1500 hp and alloy with a GT45 strapped to the side oer maybe twin TO4ZR's. Backed with a 1300HP 4l80e and some sort of muther of a transfer and diffs, or is that just me?? Why not an 8 sceond patrol??
PGS 4WD wrote:If money were not an issue eveyone would have a 488 CI L7X World Block, higher decks, more head bolts, good for 1500 hp and alloy with a GT45 strapped to the side oer maybe twin TO4ZR's. Backed with a 1300HP 4l80e and some sort of muther of a transfer and diffs, or is that just me?? Why not an 8 sceond patrol??
Joel
They have those......
Monster Trucks.
6" GQ, 37" Treps, that is all.....
You have the right to remain silent,
anything you say can and WILL be held against you on outers.....
If you love them mate , go for it.
They really do produce a heap of torque, and will throw you back in the seat when you hit it...
Just do your best to keep the bolt on as light as possible......if you don't have the money for an ally block, at least try for the heads, it keeps the weight down lower.....
I'm not bagging them, I just believe you can do better, I have had so many crap engines of all sizes come across my duno over the last 10 years or so its sad. A stock 502 crate 225 rwkw in 1999, I saw 3 within 3 kw. A V10 8 litre dodge ram truck 160 rwkw. A 460 in an F250 125 rwkw. 308 holdens that detonate at 10 degrees total timing and make 120 rwkw (approx stock) So much depends on the build. Valve overlap must be considered with compression as it effects cylinder pressure, excessive cylinder pressure causes pre ignition, pinging. The type of fuel, swirl characteristics of the heads, materials, cooling system efficiency, combustion chanber shape, manifold design, the list goes on, be it big or small unfortunatly it can still be good or bad, it depends if the person committing the bits knows what they are doing, then get it tuned, and hope youve chosen well.
Ive an engine in my shop now that a engine machinist and builder of 40 years had assembled twice, big ends flogged out, and when I tore it down i found they had left an oil gallery plug out from behind the oil pump drive shaft in a 304 Holden. (they werent interested in fixing it either)
had similar as joel, conrods put in backward so no cylinder lube, crank bearings assembled dry ect ect.
Had a 650 hp 350 chev super sedan engine on my brother inlaws engine dino, piston just fell apart. gudgin still looked new, rod perfect, all the piston in bits of in the sump.
This was a $60k motor n a $450 piston, destroyed a $5000 block so now it has a $7000 block.
The big block sounds good compared to the deisel but I would still look at a L76/LS2 Holden ballarat were sellin them cheap new.
We put in LS2 and Gen111 alot and are better suited for 4x4's for comp, I do love a BB but are a bit lazy (for comp work) unless you spend the $$$$. Weekend work a BB is tops.
I am building a BBC stroker 640 cubes Twin Turbo on methanol ATM. And yes for a Patrol
NOW ABLE TOO SAY WHAT I WANT WITHOUT FEAR OF LOOSING SALES.
The person who says it cannot be done should not interrupt the person doing it.
currently building a patrol with a 5litre stroked to 396 with hopefully 6/71 in mind, moved the engine back a few inches along with the body and found a pretty good center of gravity... in your case the weight shouldn't be a problem, if you have the tools and the kno how i recommend move the engine back a good 6-8 inches and depending on the length of the tranny bein used the engine should clear the diff although in the case of a bb the measurment between the rocker cover's may be to wide and not offer enuf leg room in the cockpit and therefor may need to move the body back also... the real killler of the wallet in sayin this would have to be the engineer, but if funds alow... go for it and say to all these turboed wanker's...just my thought anyhow...
. No electronics, basic setup, ultra reliable.
to all these turboed wanker's...just my thought anyhow...