Planning Build - Engine choice and NY emissions

[Aleinsteingenius]

I am a new guy in the planning stage for a Mark V build. The engines I am thinking about are a 427 small block or a Godzilla. I would love a Godzilla with stacks (because they look cool, and I am crazy). I have read that in lower NY we have to meet emission requirements different from upper NY. That seems odd. Could a Godzilla with stack FE and a cam pass with cats? Could I take it to upstate New York and get tested there? Could a stock Godzilla with the Holley FE pass? Could the commonly used 427 small block pass? I really like the sound of pushrod motors. The Coyote is a great motor but doesn't fit the sound I associate with Cobras. I hope you all don't mind questions from a new guy. There will be many more.

[Blitzboy54]

Yes unfortunately lower NY has a different standard than upstate. However lots of these cars get built in Long Island for example. There are active members on the board that have built and registered both 427’s and Coyotes. I’m sure some of them will respond to this. I think either engine is doable.

Funny thing for me was I registered my first car without any problem. Then when I went to inspect it the first time the shop asked me what it was. I said a 65 Cobra replica. They imputed it into the inspection system as a 65 AC Cobra. That was it, no matter where I took it after that my VIN would come up in the system as that.

Also keep in mind at least my understanding is the emissions test is computer based. They rely on the cars computer to tell you if there is an issue. If you’re using a control pack all this systems are missing. So they plug in, get no error and move on.

Good luck, I look forward to yfolling along with your build.

[Namrups]

I have a 427 in upstate NY. It was grandfathered in as a pre emission engine. It does not have a OBD11 port and does not get tested for emmissions. Only has a pvc valve.

[Aleinsteingenius]

I am on Long Island. My ideal set up would be the Godzilla with stacks FE and a cam. In 2005 we built a chopper with a 121 cubic inch billet motor with 11.5 :1 comp. Just 12" long exhaust pipes, no mufflers at all. About 150 hp. A local shop inspected it every year no problem. I should probably talk to them. I saw something that said if you use a block of a type that was manufactured pre-emissions that would work. Maybe that is why so many use the 351W engine bored to 427? I just don't want to drop 25k on an engine I cant use. Plus I have to know what engine to order my kit. Really trying not to outsmart myself for once.

[danmas]

Have you seen this? https://www.theinfamousproject.com/shop/ford-7-3-godzilla-v8-motor-swap-package/

No idea if it would work for you but it’s interesting….

[Jeff Kleiner]

...I saw something that said if you use a block of a type that was manufactured pre-emissions that would work. Maybe that is why so many use the 351W engine bored to 427? I just don't want to drop 25k on an engine I cant use. Plus I have to know what engine to order my kit. Really trying not to outsmart myself for once.

Although you can take an OEM block 351 Windsor to 427 inches it's really pushing the limits due to how thin the cylinder walls can be come and because of the less than desirable rod angles that it creates. Most 427 Windsors are built from aftermarket blocks (Ford Sportsman, Dart) which can be safely taken out to 4.125" bore which allows them to use less severe rods & crank combinations. Of course an aftermarket block is not going to satisfy a "pre emissions" requirement. Godzilla is a whole other story and although it can fit into the Mk5 it requires changing out the front dress, timing cover, oil pan and pump system for ground clearance. Then you still have the emissions question...

For what it's worth I've done two Mk4s for customers in New York ---one a Coyote and the other an EFI 302 and neither had emission related problems (there were some other kind of silly requirements such as for padded sun visors and the like which they were able to work around). What I got from both of them was that there are some inspection locations that are known to be more "friendly ;)" to these cars than others.

Good luck!

Jeff

[Waterman]

Hi, I am in Rochester upstate NY area and taking the safe approach. My conversations with NY DMV was that emissions are based on the age of the engine, so hint was to use an old engine, pre-80's that has a documented history, not stolen. Once on the road we can then modify without concern. So I purchased a cheap running old Carb engine from a junkyard and married it up to heavy duty clutch and TKX tranny. My understanding is that it will be registered as a 2025 Custom. My MkIV is in paint right now so will be going thru NYS process soon. Side issue but think about Paint early on as costs are Very high and all over the map. Also time to get it painted can be many months.

[Joel Hauser]

I think New York State is very supportive of the homebuilt custom car builder. I live outside of Albany. My Mk4 is registered as a "homemade or custom" vehicle, and is therefore exempt from emissions rules. If you make the mistake of registering it as a factory five, as opposed to homemade or custom" it will not be exempt. I know because I made that mistake when I first registered. However, two years after I made the mistake, DMV allowed me to correct my error. Now when my car is inspected, the shop only does a safety inspection and checks that I have a gas cap and PCV valve. (altho the shops usually just ask that I turn on the lights and toot the horn). Did you look at this?
https://dmv.ny.gov/registration/register-a-custom-or-homemade-trailer-or-vehicle

The State regulation says this : (i) Emission control devices. The following items must be inspected on vehicles subject to a low enhanced or OBD II emissions inspection, except that diesel-powered vehicles that are subject to the OBD II emissions inspection shall not be inspected for items 1 through 8b. A vehicle must be inspected only for the items with which it was originally equipped by the manufacturer. Vehicles classified as homemade or custom on the certificate of registration are only subject to the gas cap inspection/test described in item number 8b:" N.Y. Comp. Codes R. & Regs. tit. 15, § 79.24

This process has worked for me.

[Aleinsteingenius]

Thanks guys for all the good info. I think I read somewhere that here in downstate NY even old blocks are subject to emissions. It seems so weird that one state could have different rules to get registered in different parts of the same state. I am wondering if I could register as a 65 homebuilt with a modified Godzilla here on Long Island. Or is a modified Godzilla ...cam, stacks, higher comp....could meet emissions with cats. If I live downstate but get the car inspected upstate? Now I have a headache...

[GoDadGo]

For a stock block you may do an over square build you can up the displacement to 425 CID using a 4.030" overbore and 4.170" stroke.
Should you go down this long stroke path, gear the car appropriately since this will be a high torque lower RPM engine.
Personally I think you'd be happy with the more common 393 (4.030" X 3.85") or 408 (4.030" X 4.00") engine combo.
Just know that you'll need some really free flowing heads to handle the larger need for air with that many cubes.
Here are a few rotating assemblies to consider if you want to go for big 425 displacement with a 4.030" bore:

https://www.summitracing.com/search/brand/eagle-specialty-products/make/ford/engine-size/5-8l-351/engine-family/ford-small-block-windsor?N=part-type%3Aengine-rotating-kits%2Bactual-engine-displacement%3A7-0l-425

Good Luck From The Dark Side!
Redbone Is Running A 383 SBC / 4.030" X 3.75" Rotating Assembly

[Mike.Bray]

I absolutely love pushrod engines, every time I drive mine the sound of that rumble is such a rush. I love everything about my car but the sound is at the top of the list. You just don't get that from a Coyote. More like a purr.

As Jeff pointed out, taking a stock Ford 351W block to 4.125" bore is risky. Trying to swing a 4" stroke is probably going to require some clearance of the stock block also. I built a 393, 4.030" bore x 3.85" stroke. Even though I have a Dart aftermarket block that could comfortably go to 427 I liked the longer rod in the 393 for more low end torque. And there's no issue at all of running stacks on a SBF.

https://www.imagecoast.com/images/MichaelBray1/20250301140452mediumrotated.jpg

A word to the wise, if you're going stacks go with Borla and a Holley Terminator X. The others are cheap imitations that will give you nothing but grief.

[Blitzboy54]

Here is another kicker. The NY DMV relies on you to tell them what’s in your car. The reality is you can put absolutely anything you want in it. There are 3 different inspections. The only one that cares takes your word for what’s actually in it. Literally no one else in the process looks by design.

Joel is right. Call the home built car division. You have to deal with them anyway. They are on your side and generally very helpful. Also drop me a DM I’m happy to have a phone conversation about my experience.

Good luck.

Jesse

[Jeff Kleiner]

...As Jeff pointed out, taking a stock Ford 351W block to 4.125" bore is risky...

Actually Mike I was talking about taking a stock block out to 4.060" being risky. Taking a stock block to 4.125" will result in a view right into the water jackets!

Jeff

[Aleinsteingenius]

Wow Mike! That is the look and I am sure, performance I would like. Jesse I will DM you, when I figure out how, I am new here. Best to figure this stuff out before I order the kit.

[UKSNAKE]

Hi

Im also planning a new Mk5. Im on the list for the 30th anniversary, but was thinking 427 or FF coyote set up. Im interested in what made you think Godzilla. They seem much more challenging to put in as they are enormous and then take up engine bay space for maintenance too. I get that godzilla is more lower torque (I think) and Coyote is more revving (I think). Can any experts/ experienced builds chime in here? I will be building in North Virginia.

[Aleinsteingenius]

Uksnake,
When I visited FFR a few weeks ago. I saw the MK5 with the Godzilla in it. To my untrained eye it looked like it had more room than the Coyote. Coyotes are really wide. The Godzilla's challenge appears to be height but they had a Holley FE on it and a Holly pan. My idea motor I think would be a Godzilla with stacks. One engine company offers one supposedly set up for Cobras. 675hp. I know that is crazy but I am a guy who used to do aerobatics in antique airplanes. The problem I think it is a new engine and I don't see how that could pass emissions here in Long Island with the cam, higher comp, and stacks. Others have done pushrod 427s here and got them legal. Maybe because they are an older engine? I love the 427 Mike Bray posted a pic of with stacks. Maybe with Borla stacks and cats?.