The Dodge Challenger Message Board

I have a question for the list about fitting a stroker crank into a 440.

Can anyone tell me what internal mods are necessary to a standard 440 block in order to fit a MP 4.15" stroker crank and would a street 493" car be much more powerful (torquey) than a 440 or just use more fuel unnecessarily?

Would fitting a new rotating assembly save significantly on the cost of machine work and labour on the original worn parts?

Basically is this a worthwhile mod to a standard street driven 440 considering that I need the engine rebuilding anyway.

Looking forward to any replys.

A new crank (you may also need shorter rods) used to be a VERY expensive thing but not any more. However it is still a lot more expensive than just fitting oversize pistons on the stock crank and rods.

I think 4.15-inch is as big a stroke as you can go without mods although if any mods are needed it is usually just a bit of low-tech grinding to make sure the rod big ends miss the bottom edge of the block casting.

Increasing the cubic capacity will make more torque (you are burning more fuel - so making more energy) at a lower rpm than you would have at the standard bore and stroke.

It will also make a given cam feel more 'tame' than it would otherwise.

More cubic capacity coupled with an increase in cam lift/duration will give you more power over the whole rpm band.

The drawback is piston speed. Long strokes mean the piston has to move a lot faster. It has to cover a longer distance in the same space of time. This means friction losses (and wear!) are higher and they increase with rpm so torque can drop off faster at higher rpms than with the standard stroke. However if your peak torque is far enough up the rpm scale this is not a major problem and is more than made up for with the increased power.

Check out http://www.hughesengines.com/crank_kits ... _index.asp for an idea on prices.

Stroker kits costs somewhere around 2000-2500$ depending on the different options you choose like forged/cast crank, balancing etc. It should fit in your stock block without any mods if you go for the 4.15" crank. The stroke could be choosen up to 4.5" but then you need to do lots of mods to be able to fit it in the block. So just go for the 4.15"

Also, as Dave already mentioned, it feels like you have a cam 2 steps lower in duration. Therefore it runs/sounds much more streetable. Depemding on wild you wanna go I would look for a new cam. What are your goals performance wise? If you would like to go real fast get in contact with Scott Brown from www.Straightline-perf.com He's the man to get in touch with concerning cams. I spoke to him when I had plans for a 493 too and he was very helpfull. (Even after he had the cam ready I could cancel because I changed plans, how 'bout that) Tell him your goals and all specs of the car and will give you the needed advice.

So is it worth it ? $$ wise it's definetly more expensive then a std. rebuilt but the extra performance is worth the money if you have the cash to do it. Forget about the extra friction & wear Dave mentioned (sorry Dave), these stroker kits have a so much lighter assembly (lightweight pistons for example) then the stock assembly (way to heavy pistons) that it gives maybe even less friction.

By the way, I just checked my old mails and this was the cam advice I got from Scott: "The specs are 266/272 @ .050, .630/618 lift with 1.5 rockers. The combo should really work well together"

But all of the above is just my thinking & experience off course.

Good points Hans but I stand by what I said about friction losses and wear. Lighter weight makes no difference to that. Lighter weight does give you fewer losses in other ways (mass changing direction) but that has nothing to do with friction.
I believe a good high performance engine design should have as low a piston speed as possible. This gives a much higher rpm potential.

However I also said that in this case (440 with a 4.15 stroke) the gains outway the losses.

Whether the gains are worth the dollars is another question.

Allright Dave, maybe I should have said it different; the RB stroker will give you more friction indeed, but the wear this friction gives is less then to expect as the assembly is lighter in weight.

Maybe try and find a 400 block, fit the stroker kit and you've got also 493"

In a certain way every hp gain is worth the money as you get used to the performance way to soon. But then again, there has to be money to do it.

Thanks for the replys, the goal if there is one, is to have a high torque engine with good idle and good vacuum, main performance from idle to say 3500rpm. The vehicle would be purely for street use with factory exhaust manifolds, E-heads and eddy performer inlet manifold with 3310 or road demon. I would also want to keep the standard valve gear and stick with a 'very' street cam selection.
My main concern is that to go this route may not be worth the extra expense over and above a standard 440 rebuild. To be honest it's not something I know much about, but I am happy to accept advice from those more knowledgable in this field.

For the sort of engine you want you would be wasting your time and money with Edelbrock heads and a stroker crank.

With a rebuild and a good cam making power where you want a normal 440 is all anyone would need.

Buy a set of Keith Black pistons in the 9.5 or 10 to 1 compression range. Get the stock crank and rods balanced with the pistons/harmonic balancer/flex plate.

Get the block hot tanked and re-bored to suit the pistons (KB pistons need a specific piston-to-wall clearence).

Find a set of 452 casting heads with the hardened valve seats (if you have not already got them). Clean them up and smooth the bowl area behind the valve in each port. Fit a set of good stainless valves or clean up the stock valves if you are on a budget.

Fit a Hughes Engines cam #HEH1019BL and a good timing chain.

The performer intake is a good choice but you do not need a fancy race carb for low rpms. Stick with a 750cfm Holley or Edelbrock (my choice).

This engine will pull like a train from idle to 4200rpm.

Basically this engine/cam combo is for 4x4s that need to pull heavy loads.

If you want a bit more top speed and overtaking power at highway speeds you need power further up the rpm scale.
These two cams might be more suitable and will still give you good mileage and work with stock componants/exhaust etc. as well as the common 3.23 to 1 rear gears.

HEH1523BL is good from idle to 4800rpm and HEH1928BL runs strong up to 5200rpm.

Make sure your lifter bores are well within spec with these fast rate of lift cams. Otherwise they work VERY well indeed.

Dave's right. For these goals stick with 440cid, stroking it is a waste of money for your performance goals. The rpm range were eddy's will make the diff is up high were you don't want to rev yours. So stick with what Dave said.

One thing for Dave, a road demon is NOT a fancy race carb. Actually is the most 'mild' carb Demon sells besides the road jr.

I just meant that at the performance level he is talking about he need not spend a lot of money on a carb. He needs to get the one that is the easiest to tune if anything. Whatever the make.

Again thanks for the input. However I'm surprised you think it best I go with my stock heads - 3462346 - I think the cost of getting these rebuilt will be significant especially with vavle seats. bronze guides, possibly s/s valves and cleaning/machining. I was thinking I would take advantage of the current exchange rate and get a new set of e-heads?

The problem you have is that you want a low rpm - high torque engine.

To keep it simple let us just concentrate on the intake side as this is more critical.

High performance heads have large volume intake runners to give more flow. That is fine because they operate at high rpm. At low rpm they do not work very well.

Why?
Because the bigger the head port the slower the air/fuel mixture moves down that port at any given rpm.

Intake velocity is important in every engine but more so in an engine like this. You need to keep the intake mixture at a high enough speed to stop the fuel from de-atomising and forming larger droplets. Slow the intake charge enough and a significant amount of fuel will drop out of suspension altogether and run as raw wet fuel along the port into the engine.

This is a bad thing. As intake air speed drops you will get less efficency, poor throttle response, less torque, prone to pre-ignition, washing of the cylinder walls, diluted oil, drop in intake vacuum.

So what you need on a low rpm engine is more narrow ports. This will create a fast intake charge but as your rpms are low they will still flow enough for your engine. The heads you have are perfect for this as they made the port slightly smaller in that casting number I think. All you need to do is smooth it out with a grinding kit from Frost here in the UK and fit some valve seat inserts. Use the stock valves to keep costs down if you like. In fact you could live without the valve seats. An engine will go for years and years on unleaded fuel without seat inserts. Don't believe all that crap you hear about needing them. It is a long term thing or high mileage thing.

Advertise for a set of 452 casting heads. There are people that still think these are 'smog' heads so you can get them cheap. In fact they are almost the same as the high performance 906 heads but with hardened valve seats.

I agree it might be cheaper to buy a pair of after market heads from the USA but you are not building a high HP high rpm engine so you would be fitting parts that are totally inapropriate for your engine.

Thanks Dave for that info. Is there anything I should check on these heads before I go to the expense of having them rebuilt? I read that they can crack which makes them junk. Where would I check to see if this has happened?

They usually crack in a line above the two center exhaust ports I think.

A decent motor engineering place can pressure or vacuum test a head to check for leaks.

Check for wear on the valve stems (measure the diameter at several places along the stem length) and in the guides (see how much the valves 'wobble' in the guides when you lift them a half inch). If you get new guides fitted get them finished honed to fit your valves. So if you are going to get new valves get them first and give them to the engineers.

Follow up on cost to rebuild the cast heads. I was quoted £600 for the two heads. Clean, skim, prep valves, reseat the valves, bronze liners. Pressure test £100 more. So if I want s/s valves and viton seals etc we are over £1000! With these costs I have to admit that I would rather get some new ally heads even if I have to change my performance goals a bit!
If I were to go for the eddys what could I do with the cam and short block to keep within a high torque envelope!!

To use the Edelbrock heads you would have to move the torque up the rpm scale (longer duration cam) and fit lower gears in the axle.
In other words make the engine rev harder for the same speed.

The advantages of this are that you will make more horsepower for the same amount of torque and the torque multiplication at the rear wheels will be greater.
This is why for performance we all do this.
Read what I wrote about Horsepower and Torque theory in this section of the board.

Getting machine work done over here is expensive isn't it.

Look here;
http://www.hughesengines.com/heads/hp_bb.asp

Hughes Engines do a RV/Restoration head fully built for $700 a pair. Phone Dave Hughes and talk to him about what you are trying to do. He might be able to supply you a pair of core heads if it is cheaper than shipping yours over. He did this for me when he did my heads. I can honestly say I have been more than happy with his work.