427R Owners

[Gus M]

Looking for input from owners of Roush 427R motors.

I'm looking to have a 427R installed and use the car as a street driver, car shows and for cruises. No track use.

Here's what I would like to please know from you, based on your experience:

1. Will I have any issues in driving the 427R around town with stalling or bucking when accelerating from a a stop light position; or,

2. Will I have an issue with the torque curve in making a turn around town at low RMP's?

Knowing that the R stands for "Racing" and even though I will not be racing this car, I like the lumpy cam and the mystic of the R. Your input is appreciated.

Thanks

Gus

[FredG]

1. No

2. No

I don't know what differential ratio you have. I have 3.70 in my car. It should take you about 15 minutes of driving to figure out the torque with the R. It doesn't like to be below 1500 rpms but that has never been a problem. It has never stalled.

This engine has a tendency to run cool. I have an oil cooler on mine. The oil never gets hot enough. I will be installing a oil thermostat on mine shortly to get the temp of the oil up.

[jhv48]

Read this thread.
427R Drive Ability

[twobjshelbys]

Ahem. Didn't you already ask this question, here:

Roush 427 SR verses R

?

[Gus M]

Originally Posted by FredG

1. No

2. No

I don't know what differential ratio you have. I have 3.70 in my car. It should take you about 15 minutes of driving to figure out the torque with the R. It doesn't like to be below 1500 rpms but that has never been a problem. It has never stalled.

This engine has a tendency to run cool. I have an oil cooler on mine. The oil never gets hot enough. I will be installing a oil thermostat on mine shortly to get the temp of the oil up.

Thanks Fred. Your input is helpful. Ratios will be a 3.55.

[Gus M]

deleted

[Gus M]

Originally Posted by twobjshelbys

Ahem. Didn't you already ask this question, here:

Roush 427 SR verses R

?

twobjshelbys, I did. But I now would like to hear from as many actual owners of 427R's as possible. We heard from some on the other posting, as well as others with good input. Hoping to get as many owners as possible to share their personal experiences.

[FredG]

When you go through that thread, you will be hard pressed to find people who actually own a car with the R in it. So where are they getting their expertise from? Word of mouth. Someone else's opinion? There are about half a dozen worthwhile comments on there from actual owners. The thing boils down to one comment in particular...... "I mean ..one does not buy a race car and expect it to drive like a Rolls." and pretty much sums it up.

Originally Posted by jhv48

Read this thread.
427R Drive Ability

[Gus M]

Originally Posted by FredG

When you go through that thread, you will be hard pressed to find people who actually own a car with the R in it. So where are they getting their expertise from? Word of mouth. Someone else's opinion? There are about half a dozen worthwhile comments on there from actual owners. The thing boils down to one comment in particular...... "I mean ..one does not buy a race car and expect it to drive like a Rolls." and pretty much sums it up.

Good Post! This is why I would want to hear from as many of the actual owners to get their personal take on the street drivability of the R.

I am use to driving race cars with my weekend warrior ride being a Dodge Viper Competition Coupe. My other to go is a Gen V Viper running 645 hp. 600 torque. If the R is aggressive as a street driver, that's not an issue. We'll just feather the throttle to meet the required RPM's. I'm hoping to get feedback that the R will respond to that kind of feathering. From your previous response, sounds like it will, above 1,800 RPM.s. That was very helpful! What carb are you using on your R?

[twobjshelbys]

Originally Posted by FredG

This engine has a tendency to run cool. I have an oil cooler on mine. The oil never gets hot enough. I will be installing a oil thermostat on mine shortly to get the temp of the oil up.

I already did some of this in your other topic so I'll do it again. SEARCH will turn up more as many or most of the people that have had them and commented have moved on.

Mine was the 427IR - fuel injected but with the racing cam. I also agree that it ran cool but that is not the cause of the Roush cam or anything else. The primary cause is that the Cobra is "over cooled". The radiator (if it's the aluminum one that Shelby and others use) is oversized.

To add to the over cooling, the oil cooler acts as a secondary radiator. Indeed, had I kept mine another season I would also have added an oil cooler thermostat or completely bypassed the cooler (but left it for aesthetics).

The engine is lopey. I also raised my idle (with the DFI controller) to about 1100. It never died on me but it was just too bouncy. I didn't want my milk churned into butter.

The engine does not like to be run at low RPMS. But that is also probably true of any of the Windsor based high displacement engines and probably the FE too. It always felt that it was begging to run higher RPMs like it wanted the cobwebs blown out 2500 might be a threshold, I don't know - it's been so long. In this case I think the cam might be a contributor, but I asked others about 427s (both FE and Windsor) and everyone felt that the engine was oversized for street use. It was a race engine and wanted to be used as such. High RPMs for extended periods of time. I preferred to keep the RPMs up and thus rarely drove it any higher than 3rd in the city, 4th on the highway (except on the freeway then 5th).

I'll reiterate this statement. If I were to buy another Cobra (and I was going to for a while, but now toys are off the table) I would instead get a 289 based car. The smaller V8 can handle the street type driving with no troubles at all and the 289s won plenty of races before the 427 came along. I think most people get the 427 cars because they like the appearance, but you get most of it with the 289FIA. You're asking the wrong question. You should ask which engine, but which car.

I'll reiterate: If you want a streetable Cobra, ditch the 427 and get a 289.

PS. I have the R cam specs somewhere. It was a standard Ford cam used in Windsors found in either Lincoln or Mercury (can't remember which)

[saki302]

My car came with the R. If I were putting one in, I'd likely go SR because you won't likely miss the last 50hp.

I set my idle around 1000 rpms, it feels best there. Around town it drives fine, no bucking or issues.

The car is light, so you won't really miss the torque loss below 3k, but expect to downshift when passing sometimes. The motor does not like to lug around under 2000 rpms, drive accordingly.

I bought a tuned AED carb from Randall at cobra valley- that's the best motor upgrade you can make, it drives so much better than the holley 4150hp it came with. Much more responsive at thebmiddle/bottom. Just order a carb and run it from the beginning with the aed.

-Dave

[Gus M]

Originally Posted by saki302

My car came with the R. If I were putting one in, I'd likely go SR because you won't likely miss the last 50hp.

I set my idle around 1000 rpms, it feels best there. Around town it drives fine, no bucking or issues.

The car is light, so you won't really miss the torque loss below 3k, but expect to downshift when passing sometimes. The motor does not like to lug around under 2000 rpms, drive accordingly.

I bought a tuned AED carb from Randall at cobra valley- that's the best motor upgrade you can make, it drives so much better than the holley 4150hp it came with. Much more responsive at thebmiddle/bottom. Just order a carb and run it from the beginning with the aed.

-Dave

Thanks Dave, this is helpful on idle setting and now that you and Fred have both mention keeping RPM's up. My style of driving is always in the higher RPM mode anyway. Keeps the car always ready to go.

[FredG]

My car was built in 2014 and has low mileage....3k. The original carb that came with it was an 870 Holley, dual feed, vacuum secondaries with an electric choke. Choke got taken off. I thought it was the wrong carb because they now send the R out with 770's. I reached out to Roush and they confirmed that the 870 was original to my engine. I since replaced the carb with a newer model that is polished with half blue. I stayed with the 870. I wish I had went with a double pumper but I replaced the vacuum secondary unit with an adjustable one by Quick Fuel and that works out very well. I didn't want fuel injection. See the pics.

Originally Posted by Gus M

Good Post! This is why I would want to hear from as many of the actual owners to get their personal take on the street drivability of the R.

I am use to driving race cars with my weekend warrior ride being a Dodge Viper Competition Coupe. My other to go is a Gen V Viper running 645 hp. 600 torque. If the R is aggressive as a street driver, that's not an issue. We'll just feather the throttle to meet the required RPM's. I'm hoping to get feedback that the R will respond to that kind of feathering. From your previous response, sounds like it will, above 1,800 RPM.s. That was very helpful! What carb are you using on your R?

[Gus M]

Originally Posted by jhv48

Read this thread.
427R Drive Ability

Thanks Jim, Reading the post gave some insight. Glad you shared it!

Gus

[mikeinfo]

I recently purchased a SP Cobra with the Roush 427R Motor. Can anyone tell me what oil type/weight is recommended? Also, how much oil does it take and the oil filter (would like to get ahead of time before removing). Thanks for any info! Sorry if this has been answered before.

[Gus M]

Originally Posted by mikeinfo

I recently purchased a SP Cobra with the Roush 427R Motor. Can anyone tell me what oil type/weight is recommended? Also, how much oil does it take and the oil filter (would like to get ahead of time before removing). Thanks for any info! Sorry if this has been answered before.

Mike,

10 W 30 per Roush Website

https://www.roushperformance.com/engines/427-r.html

How do you like the R for street use?

[mikeinfo]

Gus, Thanks for the reply! I do see the weight on the website but trying to find out how much oil the motor takes and if anyone knows the filter number. Have only driven the car a little since getting it a month ago as it is cold here! Love it so far but hard to get the power to the road with cold weather/tires. Also tires are original from 2007 so I think they are a bit hard and will be replacing them when it warms up a bit.
-OK found the Oil filter: Motorcraft FL1 Currently has a WIX filter in so I will use the same.

[FredG]

Paperwork that came with the engine recommends FL-1HP

Fred

Originally Posted by mikeinfo

I recently purchased a SP Cobra with the Roush 427R Motor. Can anyone tell me what oil type/weight is recommended? Also, how much oil does it take and the oil filter (would like to get ahead of time before removing). Thanks for any info! Sorry if this has been answered before.

[saki302]

Oil capacity depends on your oil pan- most likely itll be around 8 quarts.

I'm running the WIX fl1 equivalent filter.

My car came with a 10 year old set of Firestone tires- those things were dangerous... I replaced them with Avons which put the power down much better. Full throttle is usable in 3rd gear and up (and second if you roll on smoothly).