Roush 427 IR

mikeylikesit · #1 (**permalink**) 10-25-2014, 05:22 PM

Hey

Am contemplating buying an SPF with Roush 427 IR with FI and weber 8 stack.
Had it out for a drive for an hour and was running between 85 and 95 C on the Smiths gauge.

Can someone advise what the average temp should be running at and what would be the high end of the temperature range that I should watch out for?

Replies in C would be appreciated but I can convert

Thanks

Mike

jhv48 · #2 (**permalink**) 10-25-2014, 06:58 PM

That sounds the same as mine. Take it on a long slow, traffic jammed drive and see where the temps sit.
Make sure the fan comes on around 100 degrees and the oil temp stays below about 110. Also, question the owner regarding oil consumption. These engines have been known to consume a lot of oil. Roush states that they consider a quart every 500-700 miles as acceptable. You may or may not agree.

mikeylikesit · #3 (**permalink**) 10-25-2014, 07:10 PM

Thanks JHV, yes was in quite a lot of traffic and that's when it climbed to around 100c...outside temps were 12 celcius.

Thanks for the oil temp info, forgot about that, not used to oil temp gauge.

Yes, I have done lots of reading on these engines...read some things that scared me but I think I have an eye of what to look for. Car just had 9k worth of tuning to get efi working...it ran very well. Latest owner only put 300 miles on it but said it did not burn any.

Cold idle was 1200 rpm
Warm idle after sitting in some traffic got done to around 1000. She idled very well.

I will watch for the fans to kick on...how the hell do you know they are on? I doubt if you would be able to hear them....

What is the high engine temp to watch out for?

Car really liked to stay in higher gears in town....1800 to 2000 rpm or she liked to lunge a bit. I was very impressed with how she ran but didn't put her thru many paces.

We put it up on hoist and she looked great except for a slight oil leak where the braided lines tine into the sump/block...we have yet to check that out, hope its not nasty.

Car is 2100's SPF
Thanks for the help...I have read all the threads here and maybe asking a few newb questions....my mechanic will be seeing it for the first time this coming week....

Mike

twobjshelbys · #4 (**permalink**) 10-25-2014, 10:28 PM

I had a IR in my Cobra and a friend has an "R" in his GT40.

They have a really lopey cam, and they don't like to run slow. It will run a little warm if you are just driving on the street. I always tried to run mine in lower gears at higher RPMs to keep it happy. That meant almost all driving except for the freeway was in 2nd or 3rd to keep it above 3K RPM. Then it was "happy". Running higher RPMs keeps the oil temp at water temp (200+) Another choice is to bypass the oil cooler at the front.

P.S. If you are high altitude with the Accel DFI system you need to contact me. I think I have a tune that fixes their high altitude compensation table around somewhere.

WardL · #5 (**permalink**) 10-25-2014, 10:31 PM

My SPF fans kick on around 90C and you can hear them pretty clearly in the background if you are going slow or stopped. Flick on the fan switch to hear what they sound like if you are not sure. I wouldn't expect cooling to be the issue with this SPF. Your issue will be the next time your EFI needs a tune. Did you say $9k to tune the EFI? Back up the truck dude! I have heard you need to have someone close by that knows how to tune the EFI. Interesting the $9k tune and you have the hot idle at 1,000 RPM? My Roush SR idles at 800 when hot and sounds really cool. Totally different sound then 1,000. The water temps should stay below 100 C and the oil temps should stay below 200 C given the excess cooling capacity of the SPF. I think the engine will operate perfectly fine with oil temps anywhere below 250 C, but I've never seen my oil get that hot. Good luck!

mikeylikesit · #6 (**permalink**) 10-26-2014, 06:10 AM

Tony, Ward, thanks for the feedback....Tony, I am not at high altitudes. 9K tune also included putting in new motor mounts, but I think the tune itself, was close to 5k. The car was into one shop and the mechanic could not get it tuned, (or didn't know what he was doing), then it went to another shop where it got fixed...
Appreciate to high temp warnings for oil and coolant, at least I know what to watch for.
Mike

STEVE-O · #7 (**permalink**) 10-26-2014, 08:45 AM

Besides hearing the fans kick on, you should see the ammeter drop because of the large current draw.

jhv48 · #8 (**permalink**) 10-26-2014, 10:40 AM

Quote:

Originally Posted by twobjshelbys

I had a IR in my Cobra and a friend has an "R" in his GT40.

They have a really lopey cam, and they don't like to run slow. It will run a little warm if you are just driving on the street. I always tried to run mine in lower gears at higher RPMs to keep it happy. That meant almost all driving except for the freeway was in 2nd or 3rd to keep it above 3K RPM. Then it was "happy". Running higher RPMs keeps the oil temp at water temp (200+) Another choice is to bypass the oil cooler at the front.

Read this carefully. The "R" engines are higher strung than the "SR" engines. What that means is that they need higher rpms to keep them happy. Not the best choice for a street engine. You will be revving higher to keep it in the power zone. Low rpms will be adverse to driveability.

Also, if the trans has the fifth gear overdrive .64 ratio, make sure the engine is in its happy zone at your favorite cruising speed, Otherwise, fifth gear may be useless to you.

And the water temp should never go above 100 degrees. The SPF radiator and twin fans are very efficient at cooling these cars. The fans come on just below 100 degrees and the temp will drop immediately. Even sitting in traffic on a hot day.

cobrarob · #9 (**permalink**) 10-26-2014, 11:51 AM

I know the car you are talking about , you might want to PM me about it

mikeylikesit · #10 (**permalink**) 10-26-2014, 02:24 PM

Quote:

Originally Posted by jhv48

Read this carefully. The "R" engines are higher strung than the "SR" engines. What that means is that they need higher rpms to keep them happy. Not the best choice for a street engine. You will be revving higher to keep it in the power zone. Low rpms will be adverse to driveability.

Also, if the trans has the fifth gear overdrive .64 ratio, make sure the engine is in its happy zone at your favorite cruising speed, Otherwise, fifth gear may be useless to you.

And the water temp should never go above 100 degrees. The SPF radiator and twin fans are very efficient at cooling these cars. The fans come on just below 100 degrees and the temp will drop immediately. Even sitting in traffic on a hot day.

JHV, just to be clear your comment was addressed to me and the IR engine correct? The car has Tremec 3550 5 speed with the dana 3.73 rear end.

Thanks
Mike

mikeylikesit · #11 (**permalink**) 10-26-2014, 02:29 PM

Quote:

Originally Posted by cobrarob

I know the car you are talking about , you might want to PM me about it

PM sent

Mike

mikeylikesit · #12 (**permalink**) 10-26-2014, 03:03 PM

Quote:

Originally Posted by cobrarob

I know the car you are talking about , you might want to PM me about it

Rob.....second PM sent...thanks for the first...

Mike

jhv48 · #13 (**permalink**) 10-26-2014, 04:19 PM

Quote:

Originally Posted by mikeylikesit

JHV, just to be clear your comment was addressed to me and the IR engine correct? The car has Tremec 3550 5 speed with the dana 3.73 rear end.

Thanks
Mike

Yes, that Tremec 3550 is a bit on the fragile side for the power your engine can put down. Most will choose a beefier Tremec TKO (it replaced the 3550 and was built to be stronger and smoother than the 3550) to bolt that engine to. What's the final drive ratio of his fifth gear? Should be either .68 or .82.

mikeylikesit · #14 (**permalink**) 10-26-2014, 04:27 PM

Quote:

Originally Posted by jhv48

Yes, that Tremec 3550 is a bit on the fragile side for the power your engine can put down. Most will choose a beefier Tremec TKO (it replaced the 3550 and was built to be stronger and smoother than the 3550) to bolt that engine to. What's the final drive ratio of his fifth gear? Should be either .68 or .82.

I don't know the 5th gear on this car but can find out.
Am I at risk with the Tremec 3550?

Thanks
Mike

madmaxx · #15 (**permalink**) 10-26-2014, 06:59 PM

I have had an R and SR couldn't tell a difference. Either u have oil consumption or u don't it doesn't develop overtime.

jhv48 · #16 (**permalink**) 10-26-2014, 08:47 PM

Quote:

Originally Posted by mikeylikesit

Am I at risk with the Tremec 3550?

Thanks
Mike

Not really unless you get on it regularly. It's not meant for over 500 ft lbs of torque.

jhv48 · #17 (**permalink**) 10-26-2014, 09:26 PM

Quote:

Originally Posted by mikeylikesit

Am I at risk with the Tremec 3550?

Thanks
Mike

Not really if you treat it with respect. The Tremec 3550 is not really meant for engines with the horsepower and torque that Roush has.

cobrarob · #18 (**permalink**) 10-26-2014, 09:39 PM

Mike

My cobra has 585 Hp and I can drop the hammer on my T3550 with no issues what so ever

mikeylikesit · #19 (**permalink**) 10-27-2014, 06:12 AM

Thanks everyone so far for your input and experience....

Mike

Thunderbird123 · #20 (**permalink**) 12-24-2019, 11:24 AM

I just placed an order on a Backdraft and wanted some input on a 427R or a 427IR. For the $12,500 difference is it really worth it based on your experience with your motors you guys have invested in?