Which stroker kit?

[snowman]

I have been reading up on a few of the big block (RB) stroker kits and the 440 source 512 kit seems to be real common. I am really impressed with the dyno numbers from joflaig and a few of the others but I am curious if anybody has used the 440 sources 4.50 crank to build a 543 c.i. for street applications. The price for the kit seems to be the same as the other ones, but the 512 is the popular one. Is there any one reason over the other?


I am looking to build a high torque low RPM engine and was looking at the 543.

[suntech]

I like the big motors, but remember that you get crank and rods that are up to it.
Go big!! hehe 

[chargerbr549]

When you go past the 4.25 stroke you start having clearance problems with the factory oil pickup tube area, from what i have read sometimes you can use the 4.375 stroke crank without many problems but each block differs a little bit. You will have to go with an external oil pickup otherwise to avoid the clearance issues with the longer strokes and that starts to get expensive not to mention the extra plumbing.

Kevin

[snowman]

I wonder if that is why the 512 c.i. is popular. Are people not interested in extra plumbing in the street cars or I wonder if it is a factory engine mount clearance issue when using the external pump?

When using the 4.375 crank, any idea how much the blocks differ or in what areas they differ to make the factory oil pickup tube work in some and not the other blocks? I thought the blocks were cast in the same type of molds. 

[daytonalo]

The new 440 and Hemi blocks are cast by World products , they have revised the pick-up tube area so that a larger stroke can be had without ext plumbing .

Larry

[snowman]

Yea, I guess I could see that. I didn't mention it but I was thinking more along the lines of factory cast blocks.

[snowman]

I guess I'm just curious if anybody has used the 440 source 4.375" stroke crank in the factory cast 440 block.  I want to go as big on cubes as I can but I have to use the original type oil pickup tube and I can't seem to find a definite answer to whether or not it will work with this crank. Anybody??

[firefighter3931]

With a stock block there's no logical reason to go bigger than 4.25, inmo. Even with a mild hydraulic cam and a descent head it will make 600 ftlbs of torque....more than you can possibly hope to hook on a street tire. No problems with internal clearance....run the stock pickup a windage tray and the hemi 6qt oilpan and be done with it. 



Ron

[snowman]

Hey Ron,

I was going with the theory that bigger is better. I am actually looking at options for building an engine for my tow rig and that was the reason behind high torque low RPM requirements. I have an 85 1-ton and the 360 in it is tired. The price for the stroker kits are the same so I thought I would see how big I could go and still use the factory type oil pickup tube.   

[firefighter3931]

Hey Ron,

I was going with the theory that bigger is better. I am actually looking at options for building an engine for my tow rig and that was the reason behind high torque low RPM requirements. I have an 85 1-ton and the 360 in it is tired. The price for the stroker kits are the same so I thought I would see how big I could go and still use the factory type oil pickup tube.   

For a tow application the 4.25 stroke will be plenty. A longer stroke might make slightly more torque at a little less engine speed but the complications it creates is not worth the hassle, inmo. Even with a good flowing stock port sized head the engine will be all done by 5000 rpm with a mild hydraulic cam. It will have LOTS of low end grunt, even if you manage to overcam it. 


Ron

[snowman]

Hey Ron,

Okay, I hear ya. I'm reading just keep it simple the extra grunt is not worth the hassle.

I figured that the engine would not see 4500 rpm so you are pretty close. And because of the low rpm I was hoping to be able to use the factory cast 452 heads after opening them up with the porting templates and cleaning up the ports a bit.

Where I am trying to keep the torque window in the low rpm range would you use the 2.18/1.81 valves or leave the 2.08/1.74 valves in it?

Also, I read through the build-up on joflaig's engine where you recommended the Engle Cam K62/k64 on a 110* lsa. Would you recommend the same cam or would something different be better?

It's main purpose is a Tow rig
5500 lbs (had it on the scales)
4.11 gears
33 tall tire
727 trans
Power brakes

[firefighter3931]

Hey Ron,

Okay, I hear ya. I'm reading just keep it simple the extra grunt is not worth the hassle.

I figured that the engine would not see 4500 rpm so you are pretty close. And because of the low rpm I was hoping to be able to use the factory cast 452 heads after opening them up with the porting templates and cleaning up the ports a bit.

Where I am trying to keep the torque window in the low rpm range would you use the 2.18/1.81 valves or leave the 2.08/1.74 valves in it?

Also, I read through the build-up on joflaig's engine where you recommended the Engle Cam K62/k64 on a 110* lsa. Would you recommend the same cam or would something different be better?

It's main purpose is a Tow rig
5500 lbs (had it on the scales)
4.11 gears
33 tall tire
727 trans
Power brakes

For that type of build the 452 heads with the porting templates are fine. I would use the stock valve sizes and if possible upgrade the valves to stainless to help with increased heat and EGT's while towing. Keep the compression in the low 9's with the iron heads and use a dual plane intake manifold. As for the cam i would go with an engle K58 on a 112* lsa. If you want torque this will make enough to rip your house off it's foundation. 


Ron

[snowman]

 



Hey Ron,

First off, I sure appreciate your help with this. I have bounced some of this off of my racing buddies and they all seem to think I need to go higher in the rpm window to make any torque. I didn't think so and you have verified my claim.

I was trying to stay under 9.5 compression and had planned to use the Edelbrock Performer dual plane intake, unless you can think of a better one to use. I have not made a decision on what size of carburetor as of yet though, and I will put stainless valves on the list for sure. 

I looked up Engle's specs for the cam that you recommended. If this is the correct one the specs are 276° @.050 and .520 lift as a straight profile on intake and the exhaust side. I thought that split profile cams are better for getting the exhaust out. Would I benefit anything on this build by going with a split profile or do you think the straight one would still be fine?

As far as exhaust goes, I was thinking either the factory HP manifolds or the shorty block hugger headers and a 2.5 inch exhaust. Any thoughts on this selection?

On a side note, one of my gear head buddies is trying to convince me to go with a six pack carburetion set up and his reasoning is because I would only be using the two barrels when my foot wasn't in it and it would get better gas mileage.  I am thinking that the rpm range that the six pack set-up works best in is higher than what I am working with, besides the fact I'm sure it's gonna be thirsty anyway I don't see how the six pack would make that much difference.  Any thoughts on this? 

[firefighter3931]

Look at Mike's build which is similar to what you're wanting to build. Pretty nice flat torque curve and loads of low end grunt. I specced his cam with a little more top end performance in mind. The single plane Street Dominator intake manifold and 950 cfm carb were also chosen with those build parameters in mind.

http://www.dodgecharger.com/forum/index.php/topic,43911.0.html


Using the k58 which is slightly shorter in duration will drop the peak torque down lower than Mike's....probably into the 3500 rpm range (peak) and pretty fat (torque) right off idle. The RPM dual plane would be an excellent choice as it will only increase throttle response and torque at lower engine speeds.

As for the carb ; normally i wouldn't recommend a 750 vacuum secondary carb on a stroker but on a build like this it would be a descent choice. Smaller primaries will increase vacuum signal and make throttle response very sharp....smaller primaries also are more fuel efficient. I like the Proform carbs and they do make a nice 750 cfm vacuum secondary unit with a choke. The Proforms also flow bigger than advertised....my 750 cfm proform main body went 830 cfm on a flowbench.

For the exhaust i would go with a 1 3/4 in primary long tube header....something like a headman or whatever will fit in the chassis. The header will help the big mill exhale properly, increase scavenging and reduce intake dilution....all of which increase power. The 2.5 in dual exhaust is fine but use a good straight thru muffler like the Ultraflows/Magnaflows....stay away from a chambered (flowmaster) style muffler.


I would use this stroker kit : 440.512.5074

This one uses a 4.35 bore and a 27cc dished piston yielding just over 9:1 compression. No need to bore the block more than .030 because that just compromises structural integrity and can potentially increase overheating. The thicker you can keep the cylinder walls, the better. 


That's pretty much how i would build it given the intended use of this vehicle. 



Ron

[snowman]

Hey Ron,

Thanks for all your help. Looking at the dyno sheet on Mike's build that's the kinda torque I am looking for.

This gives me enough info to get started. It's time to start rounding up all the parts. I think it will be an interesting build using factory cast heads and wanting to stay in the low rpm range. I will keep you updated.

[firefighter3931]

You're welcome...allways glad to help out.

If you're looking for a good valvespring to use with that cam the Comp #911 is an excellent choice. 



Ron