Boosted 460 timing

I have a 66 fairlane that I put together recently with a turboed 460 with efi.    I am using a megasquirt to control timing and fuel.

  Curently it make 12 psi on a completely stock engine with a Borg Warner s480 non intercooled.    IATs are about 140 degrees.  Most of my turbo tuming has been with turbo Ls stuff.

 I am curious what my timing curve should look like.   On my intercooled Ls stuff I pull about 1 degree per pound of boost at 9:1 comp on pump gas to stay safe.    On this 460, I start at 36* and pull back to 18* by 12 psi.  I'm pulling 1.5* per pound.  I feel this is pretty safe considering I am also 11.3 afr at this point also.  The plugs don't show any signs of detonation and I want to keep It that way for now.

 What do you guys think about timing?

I haven't yet built a boosted BBF but I currently have a 317 cid supercharged and intercooled SBF in my notchback controlled via Megasquirt. I start at 36* and after 5 lbs of boost I pull 1 degree for every lb up to 12 lbs so there's 29* at max boost. This setup was dyno tuned in September and the combo really liked timing. This is just my personal experience.

Justin

Need pics of said turbo'd Fairlane!!

Do any of you guys run an exhaust gas temp sensor or knock sensor to tune with?

windsor wrote:Need pics of said turbo'd Fairlane!!

memo03.04.2016

Wow... That's a sleeper I'd say.

What do the plugs tell you it has now? Where's the timing mark? How much heat in the plug? What plug?

I have an update for you all on this.
I just recently intercooled it with a water to air set up and put a set of heavier valve springs in due to valve float at 4800 rpm.

I have been at 12-13 psi of boost with intake temps that never exceed 105*. Timing at this boost is about 17*.

I want to tell you, for what it is, this is one bad mother on boost. With 3.50 gears, detroit locker and 315-30-17 Mickey Thompson street comps at 22 psi. In high gear it is still searching for traction on occasion. 1st and second gear are essentially useless.

Boy oh boy is it a blast!



Now for the real update, I experienced a rapid uncontrolled disassembly of something in the bottom end. They squirrels have apparently clawed their way out of the bottom of the oil pan in spectacular fashion!

I will post some picks as soon as we get the motor out. I have a boost ready 523 ready to go in.

I am a little surprised. I would have thought it would have hung on just a little longer than it did.


What is anyone elses experience boosting stock bottom ends?

fastbarry wrote:I have an update for you all on this.    
I just recently intercooled it with a water to air set up and put a set of heavier valve springs in due to valve float at 4800 rpm.

I have been at 12-13 psi of boost with intake temps that never exceed 105*.   Timing at this boost is about 17*.

I want to tell you,   for what it is,  this is one bad mother on boost.  With 3.50 gears, detroit locker and 315-30-17 Mickey Thompson street comps at 22 psi.   In high gear it is still searching for traction on occasion.  1st and second gear are essentially useless.    

Boy oh boy is it a blast!



Now for the real update,   I experienced a rapid uncontrolled disassembly of something in the bottom end.    They squirrels have apparently clawed their way out of the bottom of the oil pan in spectacular fashion!

I will post some picks as soon as we get the motor out.  I have a boost ready 523 ready to go in.

Curious, how high did you rev it on average?

tbirdmike wrote:

fastbarry wrote:I have an update for you all on this.    
I just recently intercooled it with a water to air set up and put a set of heavier valve springs in due to valve float at 4800 rpm.

I have been at 12-13 psi of boost with intake temps that never exceed 105*.   Timing at this boost is about 17*.

I want to tell you,   for what it is,  this is one bad mother on boost.  With 3.50 gears, detroit locker and 315-30-17 Mickey Thompson street comps at 22 psi.   In high gear it is still searching for traction on occasion.  1st and second gear are essentially useless.    

Boy oh boy is it a blast!



Now for the real update,   I experienced a rapid uncontrolled disassembly of something in the bottom end.    They squirrels have apparently clawed their way out of the bottom of the oil pan in spectacular fashion!

I will post some picks as soon as we get the motor out.  I have a boost ready 523 ready to go in.

Curious, how high did you rev it on average?

data logs show no more than 5300 on the 1-2 shift or a burnout and about 4600 in any other gear. it layed over pretty hard by 4700-4800 with the stock cam.

Well that sucks.

Im really curious to know exactly what happened.
The rods can take some compression force, but not so much rotational.

Did you ever figure out what went wrong? Also howd the plugs look as far as timing?

tbirdmike wrote:Well that sucks.

Im really curious to know exactly what happened.
The rods can take some compression force, but not so much rotational.

^^^^^^what he said!!!

the plugs told me what i already knew, the timing was lazy.

an exhaust valve broke off which broke the piston and let the pin pull out of the pin boss and well, that is when the things got exciting.

i knew there was nothing left in the motor worth saving and i was in the middle of nowhere with no cell service and didn't want to walk so i tried and managed to get it restarted. i made it 16 miles back towards civilization. the thing made some god-awful noises during that time but kept on trucking all while sawing itself in half. it was #6 that came loose. but, i made it all the way to the edge of town.

Any updates or get any pics of the carnage? Im in the middle of a stock engine turbo build myself. Nice ride by the way!

captaingriffin wrote:Any updates or get any pics of the carnage? Im in the middle of a stock engine turbo build myself. Nice ride by the way!

thank you!
i am interested to see what you are putting together.  i love pushing stuck stuff to see what it can handle!
from my experience with the boosted stock engine,  you need some real valve springs if nothing else.    with my stock cam and stock d3 heads and valve springs n/a i could spin to 5600, at 6-7 psi from a bw s480 i could turn about 5200rpm,  at 12psi it was floating the valves by 4400rpm.   i had a set of old used oem 429 cj springs i threw on and that was good for another 200 rpm at 12 psi.

i cant recommend actual spring pressures, but, i can say with a true stock engine, you will definitely see early valve float under boost.

the turbo extended the usable power band up in the rpm range way farther than the stock cam would suggest.






the car now has a new engine in it.   523"    eagle forged crank,  eagle h-beam rods and diamond blower pistons with tool steel pins.  ported big valve doves 9.0:1 compression

i am replacing the s480 with twin 78mm turbos and ditching the intercooler in favor of pre turbo methanol injection.  i will have a 210lb fuel injector spraying 100% methanol into the inlet of each compressor controlled by the ecu.

this new setup should be capable of well north of 1000 whp on pump gas

Wow that's going to be one heck of a ride! Would love to see the progress pics of that! I currently have a build thread for my project going over on theturboforums, 65 comet turbo big block budget build. I thought about copying it here too but it seems that theres not as much interest on these boards for forced induction topics. But maybe I will anyways lol.

How did you like the s480 I am currently working on my 94 mustang with an s480 on it

Bonebrake86 wrote:How did you like the s480 I am currently working on my 94 mustang with an s480 on it

is this a big block setup or something else? the s480 is a fantastic turbo.

Yes BBF 460, some what if a junkyard build, right now it is getting a 96 efi short block with a set of D3 heads. I wanted a 88 to 92 short block to bump the compression but haven't had any luck with finding one close.

fastbarry wrote:

captaingriffin wrote:Any updates or get any pics of the carnage? Im in the middle of a stock engine turbo build myself. Nice ride by the way!

thank you!
i am interested to see what you are putting together.  i love pushing stuck stuff to see what it can handle!
from my experience with the boosted stock engine,  you need some real valve springs if nothing else.    with my stock cam and stock d3 heads and valve springs n/a i could spin to 5600, at 6-7 psi from a bw s480 i could turn about 5200rpm,  at 12psi it was floating the valves by 4400rpm.   i had a set of old used oem 429 cj springs i threw on and that was good for another 200 rpm at 12 psi.

i cant recommend actual spring pressures, but, i can say with a true stock engine, you will definitely see early valve float under boost.

the turbo extended the usable power band up in the rpm range way farther than the stock cam would suggest.






the car now has a new engine in it.   523"    eagle forged crank,  eagle h-beam rods and diamond blower pistons with tool steel pins.  ported big valve doves 9.0:1 compression

i am replacing the s480 with twin 78mm turbos and ditching the intercooler in favor of pre turbo methanol injection.  i will have a 210lb fuel injector spraying 100% methanol into the inlet of each compressor controlled by the ecu.

this new setup should be capable of well north of 1000 whp on pump gas

Hi there, I would really appreciate some information on suitable valve springs for an otherwise stock block as you have it. I have D3VE-A2A heads, an 8:1 compression engine (completely stock) and a K29 turbo. I also understood that the primary item on the engine to be changed are the valve springs. Can somebody advise which valve springs are suitable for this attempt?

From what I have seen ... boosted engines can benefit from different valve springs on the intake and exhaust.
Higher seat pressure on the intake with about the same open pressures; a little less rate on the intake springs.

A lot of people use the same springs on both and just use more seat pressure on the intake side.

Thanks / same springs but more seat pressure? How does that fit together? Shims?

Any help would be greatly appreciated. Which companies should I contact?

rmcomprandy wrote:From what I have seen ... boosted engines can benefit from different valve springs on the intake and exhaust.
Higher seat pressure on the intake with about the same open pressures; a little less rate on the intake springs.

A lot of people use the same springs on both and just use more seat pressure on the intake side.

Is there an upper limit on seat pressure? Boosted engines use more seat pressure. The engine I have is from 1973 - any problems there? Want to run 6PSI of boost.