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440 build questions

Kuruton

Kuruton

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Talking to an engine builder about having work done on a 75' 440. I want it to be completely daily-able on 93 octane but hit at least 400 crank hp and run power brakes without an external pump.

It would be stock pistons, hastings rings, roller rockers, double roller timing chain, sealed power bearings, melling oil pump, earlier closed chamber heads, performer rpm intake and dougs long tube headers. For the cam, he recommended the comp 280H, but I'm thinking the comp XE268H.

He says with the swapped heads, it should be around 9:1 compression and doesnt recommend spending the money on a roller cam or aftermarket pistons.

Looking for input from anyone with more experience. Any different reccomendations or changes they'd make. Appreciate it!
 
The key to 440 power is all the the quench zone. You need pistons that will give you ~.040" to .060" between the top of the piston and the earlier closed chambered heads. Get the quench right, you can probably get 400 hp (kinda wimpy for a 440!) with any after market camshaft out there. For power brakes you want a cam with around 112° to 114° lobe separation. Others will have different opinions, but I'm not wrong.
 
I agree, quench is a critical component with today's pump swill to avoid detonation. You can have detonation with a low compression ratio without proper quench. With proper quench and planning to run 93 octane, you should be able to run a more favorable compression ratio. Although personally, anymore I try to run a combo that is comfortable on 89 or 91 just cause those are often easier to find. But if you have ready and dependable access to the 93, then go for it.

One reason a lot of guys bypass the quench is because it involves squaring the block corner to corner. Our big blocks are usually not real square there and when going for the optimum .040", it matters. It is not hard or terribly expensive to square the block, but is another step and cost.

If you can swing it, aluminum heads would be another good addition for a number of reasons.

There are a number of Mopar experienced engine builders who have cam grinds that will do what you want to do THE FIRST TIME. Call one or two for their cam recommendations and the recommended compression ration. What you are shooting for is not difficult and has been done many, many times so there is plenty of experience to draw on.

Dwayne Porter, Porter Racing Heads has been my go-to for wedge cam grinds on my stock inch and stroker engines for years and years. He is a great guy with TONS of dyno, street, and track experience.

.
 
I agree with the above comments. I had a motorhome 440 before I built the 451 stroker. It used a lot of gas and little power even with a new cam, the new 451 almost doubled the mileage and I'm sure at least doubled the hp. The pistons are so far down the hole on the motorhome engines, no compression etc...
 
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Based on everyone's feedback, I told him id like to get my pistons below deck height to as close to 0 as possible with a new set of pistons, or to wait for his next build which will be a pre-smog 440 to get better quench. I think it was a mistake to try to make up for low compression with a cam.

Really hard to find a builder willing to ship something out to Japan.
 
You really can't go wrong with a stroker kit, but since you're in Japan and it's hard to get machine work and parts compared to here in the USA, taller pistons will work.
 
Don't go too low in the block. You have to allow for the head gasket. If you go with an iron head, you can use a thin (shim) gasket and maybe go into the block with the pistons. If you use an aluminum head, you should use an MLS (which is thicker) head gasket. The whole build has be thought out before ordering parts. Personally, I would shoot for zero deck. Cometic can make you head gaskets just about any thickness. So you can raise the head to get what you want fairly easily, but it is much harder to lower it. And measure the combustion chambers and any valve reliefs in the pistons to determine your final comp ratio.
 
Be careful with aluminum cylinder heads and Cometic MLS gaskets as the difference in metal requires the engine block surface to be pretty dang smooth usually requiring the cylinder head surfaces to be decked on the block. The Felpro 1009 composite gasket is more forgiving with similar metals but is .039" thick once installed and compressed.
 
I appreciate all the feedback and advice. If anyone knows an engine builder/supplier who would be willing to ship international please let me know. Heck, if anyone has a build they're interested in selling and can ship international, feel free to contact me as well.
 
On the Cometic head gaskets, they come with a Viton sealant already applied. The 50RA surface recommended by Cometic for their gaskets is not terribly smooth as most modern factory style MLS gaskets want a much smoother 20RA to 30RA surface.

And Fel-Pro also recommends a similar 50RA to 80RA on their MLS gaskets depending on the block/head materials. How to prepare an engine surface for gasket installation.

If the specs and build allow, I personally prefer the Fel-Pro blue head gaskets. But then sometimes even the old steel shim head gaskets can be used.

But in the end, which gaskets to use is strictly dictated by the build specs.

.
 
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