4.0 cam in a 2.9?

[cammeddrz]

Isnt the 4.0 a bored and stroked 2.9

"technically" it is but it also has a widened block and a raised deck height to accommodate the larger crank

"technically" ? i think not, as stated countless times on this forum and even on this thread: the only same part between a 4.0 and a 2.9 is bellhousing bolt up. so it is not "technically" a bored and stroked 2.9.....not even close. the deck height is taller so the 2.9 dizzy shouldn't work. the cam gears are the same, but i recall even seeing a picture of a 2.9 dizzy next to a 4.0 cam sensor and you could see the difference in length the engine is taller, wider, and longer. the fronts of the engines don't even have the same bolt patterns for the accessories.

cologne v6s are not like chevy small blocks, where you could say "a 383 is just a bored and stroked 305" because those engines are identical inside and out except for bore and stroke

 

[RustedRanger]

Not to be a nit picker but a 383 is a stroked 350,If I remember right a 305 with a 400 crank is a 334. Also even if a 4.0 roller cam would work you would need a bronze gear for the 2.9 dist.

 

[cammeddrz]

Not to be a nit picker but a 383 is a stroked 350,If I remember right a 305 with a 400 crank is a 334.

i'll explain it:
i said bore and stroke right?

a 305 and a 350 have the same stroke but different bore

a 350 and a 383 have the same bore but a different stroke

so the 383 is "technically" a bored and stroked 305, as all parts inside and out are interchangeable on all chevy pushrod small blocks

even if a 4.0 roller cam would work you would need a bronze gear for the 2.9 dist.

it would stand to reason you could remove both gears and just install the 4.0 gear on the 2.9 dizzy

*edit
i just looked it up and they call for different cam bearings. and also how do you plan on keeping the roller lifter from rotating in the bore in a non-roller block?

 

[rusty70f100]

I remember reading something along these lines somewhere, probably in the tech library.

"Turning a 2.9L into a 4.0 is about like turning a 262 chevy into a 400, but on a slightly different scale."

As to the question at hand. My book lists the cam journal diameter of the 2.9 to be 1.7285" for #1 journal. #1 journal on a 4.0L is 1.951" to 1.952". So no, a 4.0L camshaft cannot be used in a 2.9. Period.

Now there are similarities between the motors. The bore spacing is the same. Rod and main journals are the same size, so if you wanted to get creative with bore / stroke / rod combinations you could do that, providing you could find pistons that would work. Valve stems are the same size, and I believe the lengths are as well.. I don't know if the 4.0L uses any larger valves than the 2.9L, but it's something to look into.

I've heard of guys stuffing a 4.0L crankshaft into a 2.9L block. One message I read years ago said that everything cleared with the rods installed. I don't know if the guy was full of it or not, but there again... it's something to look into.

I think the two use the same head bolt layout. I also know the block to head cooling passages are different. I don't know if this difference would preclude interchanging heads. I do, however, know that you'd never find an intake manifold for such an animal so it's a moot point.

I have built a 4.0L motor with a Comp 422 cam, but using 2.9L pushrods and rockers. It worked fine, with some very slight modification to the rockers. The adjustability of the 2.9L rockers allowed me to set preload on the 4.0L's lifters.

So yes, the motors are related, but not everything interchanges.

 

[holyford86]

"technically" ? i think not, as stated countless times on this forum and even on this thread: the only same part between a 4.0 and a 2.9 is bellhousing bolt up. so it is not "technically" a bored and stroked 2.9.....not even close. the deck height is taller so the 2.9 dizzy shouldn't work. the cam gears are the same, but i recall even seeing a picture of a 2.9 dizzy next to a 4.0 cam sensor and you could see the difference in length the engine is taller, wider, and longer. the fronts of the engines don't even have the same bolt patterns for the accessories.

cologne v6s are not like chevy small blocks, where you could say "a 383 is just a bored and stroked 305" because those engines are identical inside and out except for bore and stroke

I'm not going to dispute the fact that they are different in many ways but the 4.0 has more in common with the 2.9 than any other ford V6. I have taken apart both engines side by side and compared parts. I have not measured parts with more precise instruments than a 6" machinist's ruler.

The 2.9 distributor fits like it was made to fit in a 4.0 and a side by side comparison reveals no signifigant difference in the machined parts that fit into the engine. Oil pumps are the same between both engines, main bearings are the same,rod bearings are the same, head bolts are the same, thermostats are the same, only difference in the timing set is the length of the chain, oil filter adapter is the same, crankshaft bolt pattern is the same... just off the top of my head.

It would be a worthless endeavor to make a hybrid engine though. I'm just merely trying to state that there are many similarities between the two. I've mixed and matched parts to get by before and there are some small parts that can be easily made to work between the two.

 

[RustedRanger]

Actually it is impossible to bore and stroke a 305 to 383 because the cylinder walls on a 305 are thin to start with. I believe the max size possible with a 305 block is 347 using a 400 crank. The stroke on the 400 is as big as the 305 block will take also because even with that crank the bottoms of the cylinders have to be notched to clear the rods. And all parts do not interchange on small blocks,some have different size seals for the oil pan and timing chain cover and later blocks take a crank that uses a one piece seal that uses a different oil pan and timing cover. Some blocks such as 262,307,305 have such a small bore that large valve heads will not work because the valves will hit the cylinder walls.

 

[cammeddrz]

Actually it is impossible to bore and stroke a 305 to 383 nobody actually said you could stroke a 305 to 383 because the cylinder walls on a 305 are thin to start with naturally a much smaller bore would have smaller cylinders . I believe the max size possible with a 305 block is 347 using a 400 crank. again nobody said you could stroke a 305 to 383The stroke on the 400 is as big as the 305 block will take also because even with that crank the bottoms of the cylinders have to be notched to clear the rods. And all parts do not interchange on small blocks,some have different size seals for the oil pan and timing chain cover to which are you referring? and later blocks take a crank that uses a one piece seal that uses a different oil pan and timing cover. naturally the 2nd and 3rd gen small blocks are not the same a 1st gen...or they would be first gen Some blocks such as 262,307,305 have such a small bore that large valve heads will not work because the valves will hit the cylinder walls as stated before naturally a smaller bore means smaller cylindersbesides, that only applies to certain heads (mostly aftermarket, some factory) but the water jackets, head bolt pattern etc are identical, oh yeah and it goes without saying that bastard engines like the 307's are excluded .

ok.....so you totally missed the point it was never said here that a person could bore and stroke a 305 to 383. it was said that "technically" a 383 is a bored and stroked 305
all the while splitting hairs. over cylinder sleeve diameters

and again by mentioning the later 1-piece seal blocks.

and again by mentioning "large valve" heads

this thread has been officially jacked

 

[RustedRanger]

I forget the year Chevy changed oil pan seal sizes for the small block,Im thinking mid 70's. By "thinner" I am not saying "smaller". The wall thickness on 305's is thinner so it can't be bored out much and not crack the cylinder walls. I don't understand your use of the term "technically" I guess. I said at first that I wasn't trying to be nit picky. But it obviously ticked you off,sorry. I'm not making any more comments on this and I wont read any reply to this post so drop it.

 

[DPDISXR4Ti]

As to the question at hand. My book lists the cam journal diameter of the 2.9 to be 1.7285" for #1 journal. #1 journal on a 4.0L is 1.951" to 1.952". So no, a 4.0L camshaft cannot be used in a 2.9. Period.

^^^This is the question that brought me to this thread - I was wondering if it might be possible to convert a 2.9 to a roller cam simply by using the 4L cam, lifters, rockers, and perhaps the distributor gear. I just want to verify that the above is correct, and indeed it is NOT that sample.

 

[DPDISXR4Ti]

The reason I'm looking for confirmation is that this thread on the Explorer forum suggests otherwise....

2.9 with 4.0 roller cam

I understand that there are some BII/Ranger owners on this site, and so I thought I'd share this little-known bit of info... The 2.9 will accept the roller cam and roller lifters from a 4.0 OHV engine. The lifter bore is identical, except for a retaining pin recess that must be machined in to...

www.explorerforum.com

"The 2.9 will accept the roller cam and roller lifters from a 4.0 OHV engine. The lifter bore is identical, except for a retaining pin recess that must be machined in to keep the roller lifters properly aligned. The 4.0 roller cam will fit, but a bronze gear must be used on the 2.9 distributor shaft. The stock drive gear is chewed up quickly by the 4.0 cam.

Pushrod length? I haven't determined this yet. The 4.0 pushrods may work with the 2.9, since the rocker assembly is identical. The question is whether or not the 4.0's additional deck height will require custom pushrods for a 2.9."

 

[gaz]

beleneagle,

Do you need a camshaft, manual or auto?

 

[adsm08]

beleneagle,

Do you need a camshaft, manual or auto?

The OP has not signed in since Jun 26, 2011.

 

[bobbywalter]

Where is pj

 

[adsm08]

Where is pj

He's with Wancru in the Bunker.

 

[bobbywalter]

I don't know what that is.