Boring the V8 engine to 4.0L?

[Groo]

Has anyone ever considered this? It shouldn't be too hard a job. Just think of it this way. The V8 SHO engine is based off of the Duratec 2.5L, the main difference being that the V8 has two more cylinders .

Also, the only real difference between the 3.0L Duratec and the 2.5L Duratec is the bore. So, in conclusion, couldn't one buy 8 3.0L Duratec pistons, bore the block to 4.0L, put it all together, and call it good? This would definitely produce a slight increase in performance squint .

The pistons might have to be machined to fit into the engine perfectly, but who knows?

<small>[ March 24, 2002, 04:27 PM: Message edited by: Groo ]</small>

 

[wuzzzer]

Groo:
This wouldn't definitely produce a slight increase in performance.

Wouldn't? Why bother then?

Here's your answer:
http://www.v8sho.com/SHO/perfdeadend.htm

 

[AutoSHO]

If power rises linearly with Displacement and you dont change the compression you would be looking at 277 Hp at the crank sounds fun to me!

 

[Groo]

Groo
This wouldn't definitely produce a slight increase in performance.

Wouldn't? Why bother then?

Whoops. Typo.

 

[SHODWN]

what if you went too far? From what I hear the sleeves are knurled into the block and cant be removed without destroying the block.

Again its hearsay ive never seen it

 

[RStalveyARFF]

supposedly I thought they were going to do this on Tom at SS's 96. Why don't we ask him if his car is still running? lol

 

[rakarb]

Just got done reading the SHO Shop sight, Tom's 96 is for sale.
Supercharger project done too?

 

[SHOCRUZR]

Yup, Tom's 96 TR is infact for sale. $9000 is kind of steep especially at 106,000 miles.
Supercharger?!? I don't think there's any new info about the supercharger on the Gen3.



<small>[ April 03, 2002, 06:11 PM: Message edited by: SHOCRUZR ]</small>

 

[Jason King]

You can re-sleeve ANY engine. They were re-sleeving DOHC 4.6's when they first cam out in the Lincoln Mark VIII's. Then they just started replacing motors. You can also bore and stroke ANY engine if you balance it. Balanceing your rotating assembly isn't a big deal, any high quality machine shop can do it (key phrase, HIGH QUALITY).

 

[SHODWN]

Well do one.. From what SHO owners say it can not be done (sleeving) The SLO and the duratec and the other Klingon motor may be able to.

I would stick to a SHO resource on this, not the assumptions of a NON SHO owner with Honda cams A mustang Tb and a KIA colume shift lever.

 

[AutoSHO]

SHODWN:
stick to a SHO resource on this, not the assumptions of a NON SHO owner with Honda cams A mustang Tb and a KIA colume shift lever.

Why do you feel the need to attack him? He is very knowledgeable on this, and has owned SHO's before. how many V-8 SHO owners do you think have torn apart their V-8? Any engine can be re sleeved. That is the point of sleeves; if damage occurs they can be replaced. Boring may be out of the question, but I dont see why the sleeves from a 3.0 might not work with a little effort and someone who has the desire and the $$$$. And as for his mods... to each his own, if he found ways to make it run well on a budget, more power to him.

 

[jedhead]

I wonder if we were able to re-sleeve the engine, get the same bore as the 3.0l and use new pistons, won't the balance shaft need to be rebalanced to compensate for the different rotational mass of the 4.0l engine?

Bob

 

[Mac98SHO]

Okay this is ridicoulus,

Let say SHODWN has had his motor apart more than most owners trying different mods, and help other. Though he is harsh sometimes, he is very knowledgable on this motor. (Nuff said there)

As for sleeving engine.

Consider the tolerances of this motor, yes sleeving is an option but at what cost. You bore this engine out and you will sacrifice something in return.... Like cooling problems. This car heat up quick and tend to run hot in the summer. You over bore and sleeve this motor, you will most definately have cooling problems.

That is my 2 cent worth.

 

[Mac98SHO]

Oh I am on a role tonite,

It also would stand to reason that if the 3.4L is based on an 2.5L Duretec motor (Cast iron block). The the Aluminum SHO block with extra two cylinders would have the same measurement in cylinder wall thickness. NOw I not sure of the bore of an 2.5L is but I due know the bore of the 3.4L.

Taking all this in to account you would have to over bore the block to install sleeves in the block. This reduce the wal thickness. Now expanding on the my last post if you added what appear to be .25 in in bore to make it 3.0L you would loose the wall thickness you currently retain for cooling this motor.......... Now I not saying it cannot be done, just you might want to consider this before spending the money.

 

[Jason King]

Mac98SHO:
Oh I am on a role tonite,

It also would stand to reason that if the 3.4L is based on an 2.5L Duretec motor (Cast iron block). The the Aluminum SHO block with extra two cylinders would have the same measurement in cylinder wall thickness. NOw I not sure of the bore of an 2.5L is but I due know the bore of the 3.4L.

Taking all this in to account you would have to over bore the block to install sleeves in the block. This reduce the wal thickness. Now expanding on the my last post if you added what appear to be .25 in in bore to make it 3.0L you would loose the wall thickness you currently retain for cooling this motor.......... Now I not saying it cannot be done, just you might want to consider this before spending the money.

3.4 and 2.5 have the same bore and stroke. 3.0 has thinner cylinder walls. If 3.0's don't overheat, why would the v8? Cooling is a SIMPLE thing to overcome.

jedhead:
I wonder if we were able to re-sleeve the engine, get the same bore as the 3.0l and use new pistons, won't the balance shaft need to be rebalanced to compensate for the different rotational mass of the 4.0l engine?

Bob

Bob, VERY good thoughts! Balancing the rotating assembly isn't anything exotic here. Its JUST an engine. Yes a very high output engine with a LOT of good things going for it, but its still JUST AN ENGINE It is subject to the same laws of physics as every other engine.

 

[Mac98SHO]

Cooling is a SIMPLE thing to overcome

No its actually is not simple thing to overcome. I don't think the 3.0 is aluminum block (Not sure).

The physical charactoristics on cooling of this motor will play a major role. All Aluminum motor tend to run hotter then cast iron. (laws of physics). Right now in the SHO motor the wall have ample material of both types. You remove material to put in a larger sleeve, you heat disapation (sp) charactoristic change drastically.

Okay how do you overcome this added heat load?

Answer:

1. Bigger radiator (Not offered)
2. More volume water pump (same as above)
3. More airflow under hood, (this changes design of the SHO's drag coeffecent)
4. shoot lost my train a thought. NEED COFFEE

Well I leave it at that for now.

<small>[ April 06, 2002, 09:54 AM: Message edited by: Mac98SHO ]</small>

 

[Lance Cheney]

ALL Duratecs are aluminum. This includes the 3L and 2.5L. That's not going to be a problem. Whether you can cleanly remove the old sleeve or not may be another question altogether.

Only the old pushrod Vulcan block (3.0L) is iron.

Also note that the combustion heat is contained in an environment that is the same between an aluminum or iron block, due to the sleeves. Therefore the amount of heat discarded through the block (cooling system, etc.) should be pretty much the same whether the engine is aluminum or iron. I don't see why you'd need a cooling upgrade because of that (though you would due to the bigger bore for other reasons).

-Lance

 

[Groo]

Heh, the 3.0 & 3.2L SHO engine blocks are iron.

 

[Mac98SHO]

Okay I would have to disagree. The charactoristics would change slightly. There would be less material between water jacket and sleeve would allow for more rapid heat dissipation into cooling system, thus needing better radiator to get rid of the heat. Also the before mention reason may add to the heat load.

This is all theory since this motor has not been modified to my knowlegde like we discussed.

Boring motor 30 over always add more heat load on cooling system. It just you have cooling system mods. This motor would really be no different, though she tends to run hotter as it is.

 

[Buford]

I spoke to Tom at the SHO SHop and Doug Lewis at length about the 4.0L V8 SH0.

In theory it would be a TQ monster, You would want to change cams, - I get 40+ TQ below 5k and mid low 14 ET's using desktop Dyno / desktop dragstrip.

Thinking this through you need to resleave the liners. Buy pistons and the valves could be bigger and the cam is too mild.

Vadim I think has given up development because of the est $10,000 price tag, Head gaskets would be a real issue.

Buford