Speed Denisty HP limit?
#1
Speed Denisty HP limit?
I am looking at a few options for a remanufactured motor, my main concern is the speed density system. The reason i say its my main concern is because i have a few options and for alittle extra money i can get a fairly built 351w instead of just putting in a stock one. The fairly built one has about 300hp and 375 tq ( not sure on the specs. on it but its a roller cam. 351w with a more aggresive cam., better flowing heads, and not sure on what else but you get the idea) So coming back to my question is how much can the speed density system actually handle with out causing problems? i know the 351w in my truck is rated for 225-230hp and 320-325tq so will it be able to handle a motor with 65+ more hp and 60+ more tq?
#2
First off the truck looks good... Are you sure you need a rebuild? Or do you just want to get something with more power??? Either way it's not really a HP limit... It's more the fact you are limited to certain parts that will work with the SD computer. I mean you could put a blower on and go over 300HP easily! But a blower is going to set you back a bare minimum of $2000 to set up...
As I was doing my SD build (which has yet to be run in Zeus yet), I was getting great advise about "what to do" and "what not to do" with my engine from the more Senior users on here. Basically I ended up bored .030 over, flat top hypertun pistons (more compression = more HP w/out affecting the computer), more agressive cam (however your lobe seperation has to be 114* max), chrome moly rings, and standard everything else. I plan to do my own port and polish on the stock e7 heads and intake. Also putting long tubes on with full exhaust. These changes that I made will add extra torque and HP without affecting the computer that much. The important thing about the SD motor is that it has to calculate the amount of air it needs with the computer and allows that much in. I was told not to put better heads on and had to do a specific "computer friendly" cam so that i didn't go outside the computers range to calculate the amount of air the engine needs. If you had maf the meter automaticly adjusts for agressive cams and bigger heads (SD can't do this). What I'm trying to say is you probably don't want to buy an off the shelf crate motor unless you know the parts inside and on it are the ones that would work best with the SD computer. I myself am shooting for 270ish HP but won't know until i take a dyno run...
That being said, you'd gain the most from a set of long tube headers and new exhaust (pacesetter is what i hear fit the best), Comp Cams 35-512-8 (Paul just suggested this cam to another SD roller block owner- I take notes Paul!), higher compression pistons (but don't go over 9.4-9.6:1 compression or you'll be buying premium gas! If you still need more power after that is all in you can go back later and install MAF and some new heads yourself in a weekend or two.
As I was doing my SD build (which has yet to be run in Zeus yet), I was getting great advise about "what to do" and "what not to do" with my engine from the more Senior users on here. Basically I ended up bored .030 over, flat top hypertun pistons (more compression = more HP w/out affecting the computer), more agressive cam (however your lobe seperation has to be 114* max), chrome moly rings, and standard everything else. I plan to do my own port and polish on the stock e7 heads and intake. Also putting long tubes on with full exhaust. These changes that I made will add extra torque and HP without affecting the computer that much. The important thing about the SD motor is that it has to calculate the amount of air it needs with the computer and allows that much in. I was told not to put better heads on and had to do a specific "computer friendly" cam so that i didn't go outside the computers range to calculate the amount of air the engine needs. If you had maf the meter automaticly adjusts for agressive cams and bigger heads (SD can't do this). What I'm trying to say is you probably don't want to buy an off the shelf crate motor unless you know the parts inside and on it are the ones that would work best with the SD computer. I myself am shooting for 270ish HP but won't know until i take a dyno run...
That being said, you'd gain the most from a set of long tube headers and new exhaust (pacesetter is what i hear fit the best), Comp Cams 35-512-8 (Paul just suggested this cam to another SD roller block owner- I take notes Paul!), higher compression pistons (but don't go over 9.4-9.6:1 compression or you'll be buying premium gas! If you still need more power after that is all in you can go back later and install MAF and some new heads yourself in a weekend or two.
#3
As posted above as long as you keep the cam lobe separation to at least 114 the computer will be ok. You may have to use bigger fuel injectors to keep up with fuel demands. I think the stock 19lb injectors are only good to about 260 or 275hp, but that's only if they're in good condition. For 300 hp you might want to look at some 24lb injectors.
#4
I would stick with 19lb injectors until you do MAF and heads... You might want to manually clean them youself (ask me and I can give instructions), or you can get a used set of cleaned and flow matched from ebay or another online source.
I'm cleaning and rebuilding mine with a kit from RJM... Look towards bottom of the page here... http://rjminjectiontech.com/?p=27
I'd also bookmark that page if I were you... It has tons of good Ford fuel injection parts and information!
I'm cleaning and rebuilding mine with a kit from RJM... Look towards bottom of the page here... http://rjminjectiontech.com/?p=27
I'd also bookmark that page if I were you... It has tons of good Ford fuel injection parts and information!
#6
I appreciate all the quick and detailed advice guys! Nstueve, the motor still runs fine but it dos have low compression, freeze plugs are leaking and a few other little problems so for the price of fixing everything its about the same to just drop in a remanfactured motor so i have a brand new motor to modify vs a motor with 211k hard miles on it. I think i would do what yall said and just get a remanufactored motor and pick the cam. myself. I will be ordering LT Pacesetter ceramic coated headers (had a set on my 98 z28 and there a really great quality product!) and going with a 3" true dual system with a X pipe and new magnaflow highflow cats. (dang emissions laws! ) Right now i am replacing just about everything on the truck from upper, lower ball joints, tires, leaf springs, coil springs, shocks, motor, raditor and the list gos on... so i am weighing my options because as we all know these trucks are under powered and defiantly need some more power. I will also be swapping the gears out for 4.56s to really help the motor come to life (running 33s atm and later on will run 35s when i install the lift kit). I considered switching it to MAF but the kit from painless performence wiring is about $1200 and i am not to good with wiring so i would have to have a shop install it. So at the moment i am just trying to get what i can out of the motor before i switch to MAF down the road. Once again without you guys i would be dumb founded on what to do
#7
I thought about switching it to MAF but the kit from painless performence wiring is about $1200 and i am not to good with wiring so i would have to have a shop install it. So at the moment i am just trying to get what i can out of the motor before i switch to MAF down the road. Once again without you guys i would be dumb founded on what to do
It sounds like you are dropping some serious cash on your truck. You'll have to let us know how it all ends up! I'd like to have the extra cash to do one of my trucks up nice but probably won't be in the cards for me in the near future .
I do have a suggestion though... I would look on your local www.craigslist.org for a good 351w block. I have done several searches lately in my area and there are guys selling their 351w that was rebuilt less than 50K ago for cheap! I think the last one I saw claimed 20K on the 351w and they blew the tranny so they were selling the motor for $500. Buying a decent rebuild could save you a good chunk of change and all you'd have to do is put in a SD friendly cam, swap oil pans maybe, and maybe put your E7 heads on. A very cheap and doable project... Just a thought!
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#10
Agreed^
Advance the HO cam 2 degrees, 2 1/2"exhaust and long tubes with, no more than, 1 5/8" primaries.
I would recommend upgrading to an adjustable fuel pressure regulator, because the fuel demand will be higher and SD will not compensate in open loop fueling. This will also allow the injectors to support more power if you don't have access to aftermarket tuning.
Advance the HO cam 2 degrees, 2 1/2"exhaust and long tubes with, no more than, 1 5/8" primaries.
I would recommend upgrading to an adjustable fuel pressure regulator, because the fuel demand will be higher and SD will not compensate in open loop fueling. This will also allow the injectors to support more power if you don't have access to aftermarket tuning.
#11
I am dropping the truck off tommorow at the shop to get everything installed so it will be there awhile... unfortunly i dont have the time to do any of it myself with school and work but i just picked up a airbrush kit and may do a few little things to some of the engine bay parts and who knows what else I talked to the gentlemen that will be doing most of the work on the truck and he said a remanfactured 351w will be about $1800 (thats with labor included) and that comes with a 3 year 100k mile warranty. I asked him about seeing if he can find me a crate motor that would work with my truck and the SD system and said he would look into it, but for $200 ill probably have him purchase a cam. kit and install it in the new motor well its out along with some LT headers and a few other goodies. For you that are interested here is the lengthy list of what all is going to be done...
- 6" skyjacker kit w/ new leaf springs, nitro gas charged shocks, radius arms and dual steering stablizer.
- New upper and low ball joints
- New sway bar links with bushings
- 35" BF goodrich mud terrain T/A KM2s
- New 351w with new valve covers
- Polyurthene motor mounts
- New Heavy duty radiator
- New transmission cooler
- New 130 amp alternator (dont ever buy autozone electrical parts!)
- 4.56 gears in the front and rear
- new transmission shift cable
- New rotors, brake pads
- New fuel filter, air filter
- New headlight bulbs (Hids if they can order em or ill just buy em and put em in later)
- Change transmission fluid with new filter
- Pacesetter LT headers
I may also have all the body work done at the shop as well depending on how much money i have left to spare lol I will also be ordering a few other goodies like bushwacker fender flares, westin brush guard and whatever else may come to mind... After this my savings account will offically be empty but hey atleast ill have a B.A. truck? If you guys have any suggestions please be free to chime in! As soon as i get it back ill be making a thread on before and after pics and also what was done
- 6" skyjacker kit w/ new leaf springs, nitro gas charged shocks, radius arms and dual steering stablizer.
- New upper and low ball joints
- New sway bar links with bushings
- 35" BF goodrich mud terrain T/A KM2s
- New 351w with new valve covers
- Polyurthene motor mounts
- New Heavy duty radiator
- New transmission cooler
- New 130 amp alternator (dont ever buy autozone electrical parts!)
- 4.56 gears in the front and rear
- new transmission shift cable
- New rotors, brake pads
- New fuel filter, air filter
- New headlight bulbs (Hids if they can order em or ill just buy em and put em in later)
- Change transmission fluid with new filter
- Pacesetter LT headers
I may also have all the body work done at the shop as well depending on how much money i have left to spare lol I will also be ordering a few other goodies like bushwacker fender flares, westin brush guard and whatever else may come to mind... After this my savings account will offically be empty but hey atleast ill have a B.A. truck? If you guys have any suggestions please be free to chime in! As soon as i get it back ill be making a thread on before and after pics and also what was done
#12
i think on the HP the speed density will hold is not actually a correct question. More like "what will it hold in its current unmodified state"
the speed denisty computer is a lil tricky to work with but can make BIG power with a little help
8.5 Liters of Speed Density POWER! Pics! - The National Lightning Owners Club Inc
that motors is modestly making 500hp
the speed denisty computer is a lil tricky to work with but can make BIG power with a little help
8.5 Liters of Speed Density POWER! Pics! - The National Lightning Owners Club Inc
that motors is modestly making 500hp
#13
i think on the HP the speed density will hold is not actually a correct question. More like "what will it hold in its current unmodified state"
the speed denisty computer is a lil tricky to work with but can make BIG power with a little help
8.5 Liters of Speed Density POWER! Pics! - The National Lightning Owners Club Inc
that motors is modestly making 500hp
the speed denisty computer is a lil tricky to work with but can make BIG power with a little help
8.5 Liters of Speed Density POWER! Pics! - The National Lightning Owners Club Inc
that motors is modestly making 500hp
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