Stroker twist

[Mr_Random]

I dont want to turbo it, cuase mine is used offroad and I dont like running with the RPM's that high.

As long as your turbo is matched to the peak torque of the engine, running at high RPM's is NOT a problem. But all of this is a different story...

2.2 = pt engine, 2.46= later TJ engine (three years I think). 2.5 = predecessor to the 4.0, basically a 4.2 with two missing cylinders, wider bore, shorter stroke, better cooling jacket, and a redesigned head. 4.0 = 2.5 stretched two cylinders.

The 2.5 has been stroked... once that I know of. Used the profile of a 4.2 crank as a basis, .030 over on the pistons, and got ~ 3.0L of displacement. I would expect some serious torque and horsepower gains, but not as much as he claims...

 

[bjoehandley]

Whoops, sorry for the bad info guys, I dont know where I heard that. I think its becuase the 2.5 in the dakota has the same belhousing patern as the cryco 2.2/ 2.5, and the ones with the ax-15 can be bolted up making a rear-drive turbo 2.2 application. Once again, Sorry for the hi-jack and the bad info.

-Jerry

It was worth a shot, I'd love to stick a 2.2 or 2.5 Turbo (maybe with a Masarati or 2.0/2.4 head) in a Track T with an AW4 and Chrysler 8.25" just to torque off the "if it ain't gotta V8 it ain't a real hot rod" set:firedevil IIRC one of the guys who worked on the development of the Slant Six back in the 50's was one of the lead designers of the 2.2/2.5 motor and did so prior to his retirement. Had two of that generation turbo cars before I got my XJ:guitar:

 

[5-90]

1) The AMC150ci four-cylinder lasted until ca.2002 in the Dakota, I believe. It stopped being used in Jeep in the 2001XJ/TJ, and was replaced with the DCX 148ci engine.

2) The AMC150ci was largely derived from the AMC "Modern Era" six - as indicated by the 3.75" bore. Take the 199/232/258ci block, and pull out the centre two cylinders. Throw in a crank (with a stroke that doesn't quite line up with any of the sixes!) recast to the four-cylinder firing order, et viola! - new engine!

3) There is a decent amount of small parts commonality between the AMC150 and the various sixes. Not a great deal - I believe pistons will swap between the 150 and the 199/232/258, timing sets should swap, valvetrain parts should swap (150/199/232/242/258ci in the latter two) and some of the bolt-on engine parts should swap as well. Obviously not the valve cover or oil sump, but I think the timing cover swaps, the front/rear main seal, and things like that. I'd have to confirm a list - which I do plan to do one of these days...

If you want to "stroke" a 150, you're either going to have to cast a crank to do a lot, or have one welded and offset ground to do a little. Easier to stick on a small supercharger (belt-driven Whipple comes to mind) and go that way.

 

[Mr_Random]

1) The AMC150ci four-cylinder lasted until ca.2002 in the Dakota, I believe. It stopped being used in Jeep in the 2001XJ/TJ, and was replaced with the DCX 148ci engine.

2) The AMC150ci was largely derived from the AMC "Modern Era" six - as indicated by the 3.75" bore. Take the 199/232/258ci block, and pull out the centre two cylinders. Throw in a crank (with a stroke that doesn't quite line up with any of the sixes!) recast to the four-cylinder firing order, et viola! - new engine!

3) There is a decent amount of small parts commonality between the AMC150 and the various sixes. Not a great deal - I believe pistons will swap between the 150 and the 199/232/258, timing sets should swap, valvetrain parts should swap (150/199/232/242/258ci in the latter two) and some of the bolt-on engine parts should swap as well. Obviously not the valve cover or oil sump, but I think the timing cover swaps, the front/rear main seal, and things like that. I'd have to confirm a list - which I do plan to do one of these days...

If you want to "stroke" a 150, you're either going to have to cast a crank to do a lot, or have one welded and offset ground to do a little. Easier to stick on a small supercharger (belt-driven Whipple comes to mind) and go that way.

Small amendment; I can confirm 2002 is the last year of the jeep 2.5, I pulled my intake from a 2002 TJ. Here's a good question; why did the 4.0 switch to distributorless ignition, but the 2.5 didn't? Is it the fact that the 2.5 was fairly good on emissions anyways?

Isn't an offset grind not very sturdy anyways? There are custom crank casting companies (ah! Alliteration!) around, but I'm sure the prices are up there! The total cost of a 2.5 stroker might still equal a 258 crank 4.5/6/7L stroker just because you don't have to buy/machine the extra pair of everything regarding the middle two cylinders.

Pistons, bearings, timing cover, front and rear pieces of the oil pan gasket, rear main seal, um... I'm looking in to whether the harmonic balancer/vibration dampner is also swappable... I think the 6 cylinder one is a heavier casting, so it may work like an inertia ring for the 4 cylinder... we'll see.

Water pump, all front mounting brackets, thermostat housing, valves, lifters, rockers, push rods, oil pump.

In truth, I tried to find out if the timing sets are the same so I could use a double roller set on my new engine, but the standard parts numbers don't match up between the two engines, so I didn't want to chance it on the higher-cost double roller setup.

Once I swap out my old engine I'm gonna start researching all the hi-po stuff I can do to it. All my new engine has is a premium rebuild kit, dished .030 over pistons, and a good valve job, but that's because this rebuild is one of necessity, not fun (although it has been fun).

I'm thinking; custom crank with 258 (for ease) stroke (3.88, right?), Hesco RVOB4 cam, performance valves, flowbenched head, .030-.060 pistons (which ever level is safest), balanced EVERYTHING, high flow oil pump... um... and maybe I'll try to build my own header? Everything on the market is SO EXPENSIVE, an aftermarket header would probably the single most expensive component... haha.

 

[5-90]

Small amendment; I can confirm 2002 is the last year of the jeep 2.5, I pulled my intake from a 2002 TJ. Here's a good question; why did the 4.0 switch to distributorless ignition, but the 2.5 didn't? Is it the fact that the 2.5 was fairly good on emissions anyways?

I could have gotten that year wrong. However, I think that the Dakota was the last platform to carry the AMC150 tho - but even that is a bit suspect at the moment...

Isn't an offset grind not very sturdy anyways? There are custom crank casting companies (ah! Alliteration!) around, but I'm sure the prices are up there! The total cost of a 2.5 stroker might still equal a 258 crank 4.5/6/7L stroker just because you don't have to buy/machine the extra pair of everything regarding the middle two cylinders.

Yeah, custom grinds are going to be killers. However, weld/offset grinding doesn't seem to be significantly weaker than stock casting, unless you're going to get stupid with the offset. Like, the perimeter of the crankpin being past the cheek of the counterweight/throw web. Then, you're better of getting one made one-off anyhow.

Pistons, bearings, timing cover, front and rear pieces of the oil pan gasket, rear main seal, um... I'm looking in to whether the harmonic balancer/vibration dampner is also swappable... I think the 6 cylinder one is a heavier casting, so it may work like an inertia ring for the 4 cylinder... we'll see.

Depends. If the four-cylinder is internally balanced, and the snout dims are the same, it should work. However, if you want an intertia ring, have the back of the flywheel machined and weighted - you'll get more effect out of that.

Water pump, all front mounting brackets, thermostat housing, valves, lifters, rockers, push rods, oil pump.

In truth, I tried to find out if the timing sets are the same so I could use a double roller set on my new engine, but the standard parts numbers don't match up between the two engines, so I didn't want to chance it on the higher-cost double roller setup.

Once I swap out my old engine I'm gonna start researching all the hi-po stuff I can do to it. All my new engine has is a premium rebuild kit, dished .030 over pistons, and a good valve job, but that's because this rebuild is one of necessity, not fun (although it has been fun).

I'm thinking; custom crank with 258 (for ease) stroke (3.88, right?), Hesco RVOB4 cam, performance valves, flowbenched head, .030-.060 pistons (which ever level is safest), balanced EVERYTHING, high flow oil pump... um... and maybe I'll try to build my own header? Everything on the market is SO EXPENSIVE, an aftermarket header would probably the single most expensive component... haha.

I don't see why the AMC six was "retired" - apart from the fact that Dr. Z probably didn't like running a design from a defunct company. There's nothing wrong with the AMC six, the emissions test results (on mine, anyhow) have uniformly been excellent; and if the inline six is such a bad design, then why is Chevvy bringing it back, BMW and MBZ never stopped using it, and I think Toyota and Nissan are still using it?

 

[bjoehandley]

I'm wondering if it was more of a crashing problem as well as an emissions problem. Don't know if Dr.Z had as much control as he would have like over Chrysler, he seemed to be the only person in Dahlmer that actually gave a damn about Chrysler.

 

[5-90]

I'm wondering if it was more of a crashing problem as well as an emissions problem. Don't know if Dr.Z had as much control as he would have like over Chrysler, he seemed to be the only person in Dahlmer that actually gave a damn about Chrysler.

Ah. And what would the "crashing problem" be, do you know? As I said, BMW has been using them more or less continuously in pax cars for the last 35-40 years or so, MBZ as well, and Chevvy has been bringing back the inline six (alongside the inline five) in their light trucks. Chevvy isn't alone in the I5 idea - Audi has been using them for years as well.

So the inliner isn't really dead - it's still around (although, yes, the "straight-eight" has been gone for fifty or sixty years now...) And there's nothing wrong at all with the idea of the inline six - it's a great little truck engine (and, for Cummins, a great medium truck engine as well. Don't some of the semis sport overgrown Diesel sixes as well?)

So, I ask once again, why for kill the inline six? There can't be anything seriously wrong with it, or it wouldn't be in current production. Yeah, it's a bit long - but it adapts well to truck uses.

 

[bjoehandley]

I was under the impression that they took up too much "crunch room" in the front when compared to a I-4, I-5, V-6, or V-8. IIRC Dahlmer was going to kill off all of their I-6's post take over for that reason, but BMW was going to work around the long engine/crumple zone issue instead and IIRC Nissan went away from inlines in cars like the Skyline as well supposedy for the same reason:dunno:

That said, I do think it would be interesting to see an /5 or /6 based off the current Hemi motor though:idea:

 

[5-90]

I was under the impression that they took up too much "crunch room" in the front when compared to a I-4, I-5, V-6, or V-8. IIRC Dahlmer was going to kill off all of their I-6's post take over for that reason, but BMW was going to work around the long engine/crumple zone issue instead and IIRC Nissan went away from inlines in cars like the Skyline as well supposedy for the same reason:dunno:

That said, I do think it would be interesting to see an /5 or /6 based off the current Hemi motor though:idea:

Bugger. "Crush room" be damned - if we keep making cars that are more survivable in collisions, there won't be any incentive to avoid collisions from the off. Kinda goes along with "Make a car any idiot can drive, and every idiot will have one."

You want to push for safety, improve driver training. Improve certification standards. And Hell - giving the driver's test in English only would probably be good for dropping traffic by 30% or so overall...

Typical of government - coming up with the wrong solution to the problem we're worried about.

 

[Mr_Random]

Bugger. "Crush room" be damned - if we keep making cars that are more survivable in collisions, there won't be any incentive to avoid collisions from the off. Kinda goes along with "Make a car any idiot can drive, and every idiot will have one."

You want to push for safety, improve driver training. Improve certification standards. And Hell - giving the driver's test in English only would probably be good for dropping traffic by 30% or so overall...

Typical of government - coming up with the wrong solution to the problem we're worried about.

Haha, I like your philosophy.

BMW actually built crumplezones into the casting of their I6, I'm sure that chevy has done the same with their I5/I6.

As far as HEMI based straights go, I'm pretty sure the head design on the chevy 4/5/6 is hemispherical (the irony is that the HEMI brand actually moved away from a normal hemispherical design, it's actually partially-hemispherical).

Could you give an estimate of what the safe limit for an offset grind is?

I'm pretty sure both the 2.5 and 4.0 are internally balanced, In fact a pro engine builder said that both the 258 and 242 are nearly perfectly balanced just by the selection of the firing order. He said that he loves building hi-po AMC sixes for costumers because he can charge an extra $100 for a balancing job that takes a quarter the time of most engines.

Anways, that's why I'm researching the harmonic balancer (which is incorrectly named for this applictation, right?) swappability. I'll have word soon... no worries.

 

[5-90]

Haha, I like your philosophy.

BMW actually built crumplezones into the casting of their I6, I'm sure that chevy has done the same with their I5/I6.

As far as HEMI based straights go, I'm pretty sure the head design on the chevy 4/5/6 is hemispherical (the irony is that the HEMI brand actually moved away from a normal hemispherical design, it's actually partially-hemispherical).

Could you give an estimate of what the safe limit for an offset grind is?

I'm pretty sure both the 2.5 and 4.0 are internally balanced, In fact a pro engine builder said that both the 258 and 242 are nearly perfectly balanced just by the selection of the firing order. He said that he loves building hi-po AMC sixes for costumers because he can charge an extra $100 for a balancing job that takes a quarter the time of most engines.

Anways, that's why I'm researching the harmonic balancer (which is incorrectly named for this applictation, right?) swappability. I'll have word soon... no worries.

It's more properly called a "harmonic damper" - since that's what it does (dampen harmonic vibrations.)

I'd have to have a crank in hand to take measurements from before I could give a guesstimate on a "safe limit." It's probably not very much - how much are you looking to offset? Given what I've seen of most cranks, I'd tend to think that .060" would be about the usual limit (due to the outer perimeter of the throw web vice the location of the crankpin,) and more than that would probably be classed as "extreme," and in the territory of just casting the thing new.

An "extreme" level of balance (matching to .5g or better) is really only needed on engines that are going to run sustained high RPM - else, balancing to .75-1g is just fine. How often do we spin our sixes up that far? And, if you're doing truck work with a truck engine, you're going to live down around 3,000 rpm anyhow - and a 1g balance job is just ducky there (you can go more, but why?)

The "Hemi" idea is limited by parts geometry - even the "true" Hemi is a refined "pentroof" design, somewhat similar to the later DOHC heads (those are just more of a "pentroof" than the Hemi was. However, unless you're going to exaggerate the "tulip" valve shape, it's extremely difficult to hit a true "hemispherical" chamber.)

There was a "Hemi six" in Australia - but I'm having a difficult time recalling if it was Chrysler or AMC. Probably Chrysler, but I'd have to check. I'd like to see a revised cross-draught Hemi head designed for the AMC six - but we'd first have to revitalise the AMC six in order to bring the aftermarket back up to spin. DIS/COP top plug Hemi head, cross-draught? Perhaps GDI as well? Hmm...

As far as I'm concerned, my crumple zone is your car. Don't like it? Don't hit me! The way people "drive" around here (I use that word advisedly...) I'm torn between either pouring my bumpers full of cement (cf. "slammer car") or just getting an old M113 on the Surplus market and converting it to a work truck, repowering it with a pair of 4BTs...

 

[Mr_Random]

It's more properly called a "harmonic damper" - since that's what it does (dampen harmonic vibrations.)

I'd have to have a crank in hand to take measurements from before I could give a guesstimate on a "safe limit." It's probably not very much - how much are you looking to offset? Given what I've seen of most cranks, I'd tend to think that .060" would be about the usual limit (due to the outer perimeter of the throw web vice the location of the crankpin,) and more than that would probably be classed as "extreme," and in the territory of just casting the thing new.

An "extreme" level of balance (matching to .5g or better) is really only needed on engines that are going to run sustained high RPM - else, balancing to .75-1g is just fine. How often do we spin our sixes up that far? And, if you're doing truck work with a truck engine, you're going to live down around 3,000 rpm anyhow - and a 1g balance job is just ducky there (you can go more, but why?)

The "Hemi" idea is limited by parts geometry - even the "true" Hemi is a refined "pentroof" design, somewhat similar to the later DOHC heads (those are just more of a "pentroof" than the Hemi was. However, unless you're going to exaggerate the "tulip" valve shape, it's extremely difficult to hit a true "hemispherical" chamber.)

There was a "Hemi six" in Australia - but I'm having a difficult time recalling if it was Chrysler or AMC. Probably Chrysler, but I'd have to check. I'd like to see a revised cross-draught Hemi head designed for the AMC six - but we'd first have to revitalise the AMC six in order to bring the aftermarket back up to spin. DIS/COP top plug Hemi head, cross-draught? Perhaps GDI as well? Hmm...

As far as I'm concerned, my crumple zone is your car. Don't like it? Don't hit me! The way people "drive" around here (I use that word advisedly...) I'm torn between either pouring my bumpers full of cement (cf. "slammer car") or just getting an old M113 on the Surplus market and converting it to a work truck, repowering it with a pair of 4BTs...

Isn't your last statement why the XJ stopped passing safety guidelines and was discontinued? It was actually too stiff? I don't think concrete bumpers would work well with performance and economy, haha...

PAIR of 4bts??? Sorry, don't know enough about military trucks... seems crazy! How can you even get two cummins in a truck anyways? I'm intrigued...

"DIS/COP top plug Hemi head, cross-draught? Perhaps GDI as well? Hmm..."
Lost me with all that tech talk... haha.

I would think a good balance job can do much better for the 2.5, because while it normally doesn't NEED to wind up that high RPM, it can much more safely than the sixes because of its' much shorter stroke...

Would an *extreme* offset grind also potentially cause problems with bearing oiling? Wouldn't a custom piston pin height be required after only a couple thousandths of offset, in order to not screw with quench?

Edit: just deciphered what you meant about "top plug," you were talking about coil on plug/distributor spark mounting? Don't new hemi's have two plugs per chamber or something?

 

[5-90]

Isn't your last statement why the XJ stopped passing safety guidelines and was discontinued? It was actually too stiff? I don't think concrete bumpers would work well with performance and economy, haha...

Yeah, probably. And on the cement bumpers as well. Perhaps use 3/4" plate slab to make bumpers fore and aft?

PAIR of 4bts??? Sorry, don't know enough about military trucks... seems crazy! How can you even get two cummins in a truck anyways? I'm intrigued...

M113 Gavin APC - used from Vietnam forward, and used by NASA for personnel transport as well (but I'm not so sure why.) Strip some of the armour-plate off and replace with lighter steel - could probably drop a solid tonne that way. Plenty of room inside. Just need road tyres (pix below.)

"DIS/COP top plug Hemi head, cross-draught? Perhaps GDI as well? Hmm..."
Lost me with all that tech talk... haha.

DIS - Distributorless Ignition System
COP - Coil On Plug (DIS may be COP or "remote coil" setup)
Cross-draught - manifolds on opposite sides of the head, as on V-block engines, and most four-cylinders. The cross-draught head breathes more efficiently than the side-draught head (like we've got.)
GDI - Gasoline Direct Injection. Allows for a "totally dry intake" setup, and results in an FI setup similar to that on Diesels. Mitsubishi, MBZ, and Bosch are all working on a viable setup, but it's not caught on yet.

I would think a good balance job can do much better for the 2.5, because while it normally doesn't NEED to wind up that high RPM, it can much more safely than the sixes because of its' much shorter stroke...

True - the inline six in general suffers from harmonic trouble. Not so much due to the stroke, but due to the length of the crankshaft. Ferrari gets away from the problem with their horizontally-opposed 12-cylinder by dint of having two inline sixes stuck together at the sump rails - resulting in opposed forces to reduce harmonics. Very smooth engine.

Would an *extreme* offset grind also potentially cause problems with bearing oiling? Wouldn't a custom piston pin height be required after only a couple thousandths of offset, in order to not screw with quench?

Talking more through my hat than anything else - I've not crunched the numbers on that. I don't know what clearance there is between the piston deck and the block deck at TDC, you should be able to go right to flush and select a head gasket to set quench (by compressed thickness.) If you go "proud" (piston deck above block deck,) then you're really going to want to look into altering rod length or piston compression height - with the latter being preferred, as shortening the rod will also reduce TDC dwell time, meaning you've got less time to develop peak combustion pressure (TDC dwell gives you more time to develop pressure, with absolute peak being somewhere around 12ATDC at the crankshaft for maximum "push" at maximum leverage. Please, don't ask how I know all of this, or I'll fire back with a handful of titles that make very dry reading...)

Granted, there's only so much you can do to move the piston compression height - you generally don't want to put the gudgeon pin bore where it will intersect with the oil control ring groove. You can always shorten the ring pack height, but then you have to deal with piston rock in the bore, and that's its own problem (doable with short-stroke engines, but not so much with longer strokes. The typical F1 engine probably runs about a ring pack about half as high as ours, but two-thirds of the stroke is tops for them as well. That's got a lot to do with why they can run 10Krpm all day long...)

If you're going to build a long-stroke engine to maximise torque, you're not going to need to balance it for high-RPM operation. "Stroking" a gasoline engine starts heading you into Diesel territory. Ever wonder why the redline of a Diesel is so low (typically 3000-3500rpm?) It's got to do with both the compression ratio (16:1 or higher) and the length of the stroke (piston acceleration/deceleration and stresses on the gudgeon pin, connecting rod, and crankpin.) Push the stroke too far, and you'll have to push the redline down to compensate.

 

[bluejeepkid]

Spin 44 inch boggers?

Video or ban.

uhh no, dont ban. 44's are easy to pin with the right gearing...however i wouldnt spin a 44 on a 44 lol

 

[Talyn]

GDI - Gasoline Direct Injection. Allows for a "totally dry intake" setup, and results in an FI setup similar to that on Diesels. Mitsubishi, MBZ, and Bosch are all working on a viable setup, but it's not caught on yet.

GM too... the CTS has an optional engine with GDI.

 

[5-90]

GM too... the CTS has an optional engine with GDI.

Ah - so the idea is spreading. It does have some merit, and I'd like to see it take off

 

[Talyn]

It is. The two Caddy V6 engines are basically the same thing, however, IIRC the direct injection ran smoother and had a few more horses over the non DI engine.

 

[MudDawg]

I haven't been around in quite some time but I stop in from time to time and browse around.

There is a question regarding the fitment of a double roller timing set in the 2.5 in an above post.....the answer is (not theoretical, but factual...I have TWO 2.5 motors that have the double roller chainset)...yes the set for a 4.0 fits...remove and discard the original chain tensioner and the guide from inside the timing cover....be sure to use the cam bolt/spring/pin from a 4.0 to prevent cam walk.

The 2.5 being an inline 4 lends itself well to making power at high rpm without running into the crank and cam harmonic problems that the 6 cylinder engines do. Simple weight balance of the parts is all that are needed...with good rods and good valvetrain parts the short stroke little buzzer will turn freakish rpm compared to the 5,200 or so upper limit of a 4.0.(where it starts to get into dangerous harmonics)....

I won an obstacle course race a couple of months back driving one of my heeps with a 2.5 in it....yes, i outperformed full size trucks with v-8 engines..at the end of the course, which i ran with the shift light lit all the way through (set up for 6,500rpm), the telltale indicated a max rpm of +7800rpm...the trickest part of the motor aside from the port work and valvetrain was the well prepared set of Hesco rods....and this motor has had some serious run time in the mud pit with a 50hp nitrous shot...I may have to refresh it this season since it smokes a bit now at WOT.

Kinda like the guy that went to bonneville and was unimpressed with the motorcycle that "only" ran 147 ....until he saw the Honda 50 engine that powered it...

 

[Mr_Random]

I haven't been around in quite some time but I stop in from time to time and browse around.

There is a question regarding the fitment of a double roller timing set in the 2.5 in an above post.....the answer is (not theoretical, but factual...I have TWO 2.5 motors that have the double roller chainset)...yes the set for a 4.0 fits...remove and discard the original chain tensioner and the guide from inside the timing cover....be sure to use the cam bolt/spring/pin from a 4.0 to prevent cam walk.

The 2.5 being an inline 4 lends itself well to making power at high rpm without running into the crank and cam harmonic problems that the 6 cylinder engines do. Simple weight balance of the parts is all that are needed...with good rods and good valvetrain parts the short stroke little buzzer will turn freakish rpm compared to the 5,200 or so upper limit of a 4.0.(where it starts to get into dangerous harmonics)....

I won an obstacle course race a couple of months back driving one of my heeps with a 2.5 in it....yes, i outperformed full size trucks with v-8 engines..at the end of the course, which i ran with the shift light lit all the way through (set up for 6,500rpm), the telltale indicated a max rpm of +7800rpm...the trickest part of the motor aside from the port work and valvetrain was the well prepared set of Hesco rods....and this motor has had some serious run time in the mud pit with a 50hp nitrous shot...I may have to refresh it this season since it smokes a bit now at WOT.

Kinda like the guy that went to bonneville and was unimpressed with the motorcycle that "only" ran 147 ....until he saw the Honda 50 engine that powered it...

How did you bypass the rev limiter? Wanna post up total specs? My next engine will be getting a double roller for sure! Do you think the snout length on the 2.5 crank is correct for a 4.0 harmonic dampener? I need to figure this crap out... I grabbed the mounts and stuff from a 98 2.5 and they don't line the pulleys up with the dampener, the JY wont sell me the 98's dampener, and it's a dealer-only part that I just don't want to pay $100+ for...

 

[MudDawg]

The easy way around the engine controls is to install a conventional ignition and carb...the 4.0 damper will not work...there are three distinct 2.5 damper/belt drive packages..(A) rare '84/'85 v-belt drive used on base models with no power options...(B) early serpentine and (C) late serpentine...interchangeable IF you use the appropriate timing cover, accessory mounts and damper...there are two (that I know of) different serpentine dampers that must be matched with the correct drive package.

Do not lose or damage the flywheel or flex plate to crank bolts...they are no longer available in either OEM or aftermarket and are of unique size and thread pitch...

As for specs...professionally ported and flowed head with 1.92/150 aftermarket valves..good springs/retainers, roller rockers...block and rotating assembly are blueprinted and balanced...crank nitrided...good rods...Hesco...otherwise $$$ for custom Carillos..Quench set at .040 static compression ratio 12.2...cam .595 lift 310 duration...(Clifford may or may not still have cams like this)...careful attention to detail and assembly....the carb is a Weber 38/38 DGES, Clifford headers...the motor likes a lot of igniton lead and demands only the highest quality fuel when tunes for kill....93 octane pump gas is not good enough...100 octane sunoco works ok on motor...116 if I open the blue bottle...