Engine choices

[Kodiak]

Looking for some ideas CID and HP before I order a package. I have a roadster with small block set up. I would like something with decent street manners but strong enough to put on the track for a weekend. Thanks

[Gordon Levy]

We do many 347 engine packages that are 450+hp and 408/427 packages that are north of 550hp. They both have good street manners but as a racer and one of the engine we build is ready for track duty. Please feel free to give me a call and we can talk at length.

[bobl]

Looking for some ideas CID and HP before I order a package. I have a roadster with small block set up. I would like something with decent street manners but strong enough to put on the track for a weekend. Thanks

Welcome to the craziness. You’ll surely get a lot of opinions so I’ll start with mine. The key word in your post is “package”. The whole car is a package. Get it right and it’s a ball to drive, wrong and you’ll be disappointed. The first factor is how will you really drive the car? Mostly cruising? Back roads or highways at 80+? You mention tracking the car so that leads me to believe you have some high performance experience. You can get a 347 or 427 that have similar HP and performance, but a totally different driving experience. Obviously budget comes into play. More power means better parts throughout the drive train. These cars don’t need a lot of power to be really fun. But there are some of us that too much is just right. It’s hard to beat a 347 in the 425 hp range. Get the right gears and they are plenty fast. On the other hand a mild 408/427 with tons of torque can run higher gears at less rpm for the same performance. Tires are a very important factor in the package. Street tires with very much power can be pretty scary. But, if you plan on driving in rain or cold very often then it makes the decision tougher. Get the stickiest tire you can for your type of driving. If you haven’t ridden in or driven a Roadster yet, try to do so before committing to an engine.

Bob

[GoDadGo]

Hey Kodi-Ak-Ak-Ak,

Picking a driveline and tire combination is the most important decision you will make...If you can get a ride in a couple of cars it would make your choice a lot easier to make...Just remember that the HP/Weight Ratio can get a little crazy pretty quickly so choose wisely based on the intended use of the car.

Examples:
...300 HP C4 LT1 Corvette weighs 3,400 so you have a Horse Power to Weight Ratio of 1 hp / 11.3 lbs.
...717 HP Standard Hellcat Challenger is a fat 4,430 lbs so that crazy car has a 1 hp / 6.2 lbs to ratio.
...460 HP Factory Five 2,300 lbs Dark Side Dart Roadster has a tire-shredding 1 hp / 5.0 lbs ratio.

Though I've never owned a Hellcat, I have owned a 1995 C4 Corvette from 1995-2018 and my tire-shredding MK-4 made that car feel like a worn-out Prius...Both cars had Nitto 285/40-17's (555 Street Tires) on the rear and both cars have the same ZF 6-Speeds in them and I can honestly say I'll be learning how to drive my MK-4 Roadster for a long, long time.

Whatever choice you make, I'm sure it will be the perfect balance of HP/Weight for your driving style.

Good Luck From The Dark Dart Side!

Steve

My Beloved C4 Corvette:
https://youtu.be/svZX2BMSDEs

The Dreaded Dark Side Dart Roadster:
https://youtu.be/9WEe6-wdNtA

[CraigS]

Search is your friend. There are dozens of threads on this subject.

[swwebb]

You might want to watch this video from Dave Smith at Factory Five.

https://www.youtube.com/watch?v=fpjwKZEgzj8

[Hndblt]

This video was helpful to me when they went live with it. Helped me solidify my choice for a engine, watch the whole thing its a good one.

Geoff

[SDhemmings]

carbed 408w here, approximately 500hp/500tq and I love it. As you have heard already, take a look at the whole "package". Will the rest of the current drive train handle an upgrade in power? Will the braking system handle the increased need in stopping power (especially on track). Carb or EFI? Suspension? Lots to think about and consider, its nice to have the power but you need it to be safe first.

[Kodiak]

Thanks for all the reply’s sorry the car set up Sb tko Xmns IRS 17” Power steering no other up grades as of yet.

[Avalanche325]

If you are going to track the car, Wilwoods and power steering are a must in my book. If you ever plan on an instructor or a brave passenger, two roll bars. Also for the track, keep the car light if you are serious at all.

"Too much HP" completely depends on the drivers skill level. (most people grossly overrate themselves if they haven't done autocross or track) For these cars, pretty much figure it is like the HP is multiplied by 1.7 compared to anything that most people have driven. If you have driven a Mustang with 525hp. That would be like a Cobra with about 310hp. Then take away all of the electronic nannies that most people don't even know are saving them 30 times a second in a modern car. So, at any HP level.......ease into a Cobra, never loose respect, find the limits of the car and your skills in a safe environment and you will be fine. I always recommend autocross before doing track days, mainly due to the lack of concrete walls and lower speeds.

I have a 500hp 347 and use it all on the track and even at autocross. At that HP level a 347 is snotty and very loud on the street. A 427 at that HP level would be more mannerly. Honestly, most people that put a 427 in, do it purely for that number. Maybe that is a thing for you.

[Hoooper]

Are you married to an engine manufacturer, or would you be more interested in the power/weight formula than the manufacturer? Lots of modern take-out engines weigh much less and make more power stock reliable than semi-built cast iron stuff. True small block look kind of limits you to GM for modern engines, but the coyote is very good and light as well.

Please remember to match the engine to the trans, lots of people throw the coyote behind a stock tko600, which is a poor match as the TKO600 stock setup is not good for shifting over 6,200 rpm, but the coyote revs to 7500. If you go for a tko and an engine that actually revs, it needs to be modified for that higher RPM shifting.

[edwardb]

Please remember to match the engine to the trans, lots of people throw the coyote behind a stock tko600, which is a poor match as the TKO600 stock setup is not good for shifting over 6,200 rpm, but the coyote revs to 7500. If you go for a tko and an engine that actually revs, it needs to be modified for that higher RPM shifting.

Really depends on how you're planning to use the car. Maybe for a dedicated track machine. But for the street, very unlikely you'll ever have an issue shifting the TKO with a Coyote. Drove that combination > 7,000 miles in #8674 and never had a shift issue. Granted, mainly all street driving. But a tiny bit of track and quite a few hot passes at London. No issues at all. I get that the Coyote revs that high. But (1) on the street you won't hit those revs very often. Gets way too crazy and way too fast. If you do, only briefly. (2) Unless you're power shifting (e.g. not lifting the throttle) the second you lift the throttle and push the clutch the revs drop and the TKO doesn't hesitate to allow any shifts. Pretty much a non-issue in my book and don't agree they're a poor match.

[Hoooper]

I figured strong enough to put on the track for the weekend meant he wants to push it at the track. Wasnt your TKO modified?

[bobl]

He said the car was set up for a small block but did not specify if he had headers yet to determine whether a 302 or 351 based engine. It sounds like he already has the car. So, based on that I would assume what SBF is his question.

[NAZ]

Get the biggest, baddest, most powerful SBF you can afford. Nothing less than 500HP will do, and 600HP is just starting to get exciting. The more power the higher the fun factor.

Then don't forget to get good brakes too:o

[edwardb]

I figured strong enough to put on the track for the weekend meant he wants to push it at the track. Wasnt your TKO modified?

Yes, I've used TKO's with the Liberty Gears mods. But those are to improve the shift quality and don't change the reason the TKO can be RPM limited. Tremec did address that with their new TKX. There are a number of videos that explain technically what's behind that. Don't want to argue about it. I was responding to your statement that a Coyote/TKO is a poor match at certain RPM's which might be the case but for many/most they'll never see it. I personally have the experience to back that up. The Coyote/TKO is a very common combination and you'll rarely if ever see anyone describe a shift problem. Just hasn't been the case. And that's over a long time and a wide range of uses. Plus unless you're doing IRS where a T-56 will technically fit in a Roadster (with some mods, additional weight, and higher cost) the TKO has been the only real option for the Coyote.

The OP asked about strong enough for occasional track weekends. Stick by what I originally said. Unless you're slamming the redline and power shifting, there won't be a problem. Where I see this most often cited on other forums is on drag passes. Guys struggle with the 2nd to 3rd shift. Some related to the TKO internals. Some related to technique. But just haven't seen that a lot with these builds.

[NAZ]

I ran a TKO 600 that I had faceplated by Liberty Gears, along with cryo treating the gears (increases the torque rating to 700 lb ft) and some other mods to improve positive shifting. While the stock TKO doesn't like to shift at higher RPM, a faceplate conversion will allow you to bang through those gears like a drag racer at greater than 6,000 RPM. Here's an example: https://www.youtube.com/watch?v=k6WA0FTQ4i4

And, yes you can still drive them on the street but they are not for everyone. But it is an option if you want positive quick shifting at higher RPMs.

[Kodiak]

Thanks again for taking the time to comment .Looks like 347 or 363 is going to be the choice. 450 to 500Hp is going to be plenty in a car that weighs 2400lbs . Now I think the biggest baddest BRAKES to stop this Motown city missile.

[NAZ]

Well if you're going with the short deck then the 363 has an advantage over the 347 with it's larger bore but still has a rather short rod ratio. Have you given any thought to a 331"? It has a better rod ratio and the 1.5 HP per inch required to make 500 HP in a 331 is certainly achievable and only slightly more than the 347. You'll trade a little low end torque for more HP and less wear & tear on the cylinders, pistons, and rings with that 1.66:1 rod ratio of the 331.

So many decisions...

Don't think 331 is enough engine? https://www.youtube.com/watch?v=fWA_h9NDKOU

[caesarmascetti]

363 crate motor from Ford Performance is hard to beat rated at 505hp

[rich grsc]

Well if you're going with the short deck then the 363 has an advantage over the 347 with it's larger bore but still has a rather short rod ratio. Have you given any thought to a 331"? It has a better rod ratio and the 1.5 HP per inch required to make 500 HP in a 331 is certainly achievable and only slightly more than the 347. You'll trade a little low end torque for more HP and less wear & tear on the cylinders, pistons, and rings with that 1.66:1 rod ratio of the 331.

So many decisions...

Don't think 331 is enough engine? https://www.youtube.com/watch?v=fWA_h9NDKOU

I love my 331. Wouldn't trade it for 347, it revs like a banshee
That was a 560 hp stock block engine. Amazing

[TBull]

347 big bore has the 331 crank and rods for better rod angle and the 363 piston. The larger bore unshrouds the valves and you'll get a faster rev as well. So for a small block, best of both worlds IMHO. And later you can boost the crap out of it.

[CobraboyDR]

347 big bore has the 331 crank and rods for better rod angle and the 363 piston. The larger bore unshrouds the valves and you'll get a faster rev as well. So for a small block, best of both worlds IMHO. And later you can boost the crap out of it.Who builds a fully dressed crate motor in this configuration? I like cubes, but I also like a higher-revving small block as were the original cars. In a light car, a few low-end torques less is not a deal buster at all.

[Gordon Levy]

I have built several like this for race cars. It is a great package that with a proper solid roller cam with turn 8000 revs real easily.

[NAZ]

I have built several like this for race cars. It is a great package that with a proper solid roller cam with turn 8000 revs real easily.

Kodiak, there you go -- that would make a good short deck engine choice. Have Gordon build you one specific to your application.

[Kodiak]

Thanks Naz I did chat with Levy about some ideas and packages .