Engine An engine building combo with stock Speed Density (SD) system

[Mcmahst]

I’m building my roadmap for the completion of my 73 Vert’s (will have stock 87 TBird drivetrain, which is currently in my 73 coupe) engine rebuild. My options are buy a better short block (more than stock compression, and a cam that will not completely upset the SD) or have my 87 roller block done the same. Today, my primary question is, making that assumption, what compression ratio, cam, and heads make the most sense. I have no HP goal, but the stock engine was only 150HP, and it would be cool to have a little more with a little bit more engine cam idle roll (I’m not sure what it’s called nowadays).

I suspect this is not a new question, and I have read some responses to question like this, but based on my experience in this forum, there are a few of you who have a specific combo in your head you would recommend, based on this question. That’s what I’m looking first. What I’m trying to avoid is too much CR and head for the best SD cam I can afford (afford as in what the SD system can handle).

I just paid to have my SD computer repaired by the ECUExchange guys, and want to stick with it. Remember, I’m not trying to find the line between an a functining SD system and one that I’ll hate. So, to make clear my intentions, here is the configuration I will be using, along with the rebuilt engine, with the part set you recommend:

Stock intake (but suspect I’ll need a different throttle body size)
I have stock injectors, but I suspect with the combo you suggest, I’ll need bigger?
My current shorty headers

My goal is to get what CR you would set as a goal, the specific cam you would use, what heads you would install, what throttle body, and injector size. Thank you for your help, I hope my request is reasonable and doable. Steve

 

[2000xp8]

Modifying one of these cars with speed density is a passion project, you have to be doing it because you love it. There will be trials and tribulations that most likely lead to headaches and possibly regret.
There have been guys and sites dedicated to running speed density but the sites are all gone and information is now sparse.
With that said, IMO, it makes no sense to do so, new computer or not.

The cam thing is the first issue, the injectors are a whole other problem.
When it's done most likely you would have an inferior project for all your effort.
There is no chance i build a short block without the goal of a significant power increase over a stock 5.0.

If i were to attempt this i would buy an explorer gt40 engine, add one of these cams (list copied from the corral, which i believe originally existed on .50tech which was the site most SD guys were on).
Crower 15510.
Crower 15511.
Comp. Cams #35-308-8 (266HR).
Comp. Cams #35-310-8 (270HR).
Crane #444211 (Power Max 2020).
Crane #444221 (Power Max 2030).

Change the valve springs and run it as is.
Probably be about 265rwhp. Won't exceed the injectors and while most likely it will not run perfect, should be decent.

 

[Mcmahst]

You don’t think an 87 roller block is a good starting point? I think 200rwhp would be great.

 

[Noobz347]

On a lark and particularly, because of the region that you reside...

I would search online for speed shops in your area, [call] them and ask if they can chip tune Ford OBD-2.

If not (in my efforts to save you a lot of head banging): Convert to mass air or buy a stand-alone. The conversion is really easy and you retain your OEM harness with some mods

 

[2000xp8]

You don’t think an 87 roller block is a good starting point? I think 200rwhp would be great.

I think an 87 shortblock is fine. What i don't think you should do is build a shortblock based on using speed density and definetely don't build something in an attempt to get 200rwhp. That is how much a stock 87 mustang made with, silencer delete, underdrive pullies and a catback and a k&n air filter.

You are on the opposite end of the spectrum of what we typically see, usually once a year someone shows up around here and wants 1000rwhp (it's been a while, we are do) and then disappears. You are on the other hand have quite possibly the lowest goal i think i have seen to date.
200rwhp is nothing, just run what you have.

There is a lot to unpack in your original post and the reality is that none of it is really relevant if your goal is modest 200rwhp because that's what you already have.
You don't need heads, a cam, an intake or injectors.

I'd say the status quo for a goal here is 300rwhp for a NA 302. Which would require all of the above.

 

[Noobz347]

Now, you could boost a straight-up stock cam all day long and I think you would like the manners. Even an SD kit doesn't care so long as everything else stays the same.

 

[Mcmahst]

The SAE specifications on my engine are 150hp/270tq at the flywheel. With parasitic loss, maybe 125hp at the rear wheels. If all I need is better heads, like gt-40 type, and everything else stock, that would be cool. The engine has a few miles on it, and since I’m removing it, I thought I would freshen up the short block. I know the stock engine has very low CR, so I thought I’d bump that up a little, to like 9-1.

I know most folks would rather have unusable street power for the bragging rights and the burnouts. I’ve been there, done that, and now I want a nice cruiser, maybe take long trips, drive to events where other folks are having a great time doing those things. If putting on stock, but improved Ford heads will do it, that’s great. I’m not interested at this time in a mass air conversion. Maybe I will someday. I know that’s counterintuitive to conventional thinking, but I’m ok with it.

Thanks for the ideas.

 

[LILCBRA]

Hopefully someone will chime in and correct me if I'm wrong - but could you just go with a GT40 top end (heads, intake, TB) and use an HO cam or equivalent and not upset the SD system too much? I'd think that that would give you the bump you're looking for and those parts should be relatively cheap and easy to locate.

I'm honestly not too up to date with the SD system as I plan to convert my 87 to mass air.

 

[Bullitt347]

Hopefully someone will chime in and correct me if I'm wrong - but could you just go with a GT40 top end (heads, intake, TB) and use an HO cam or equivalent and not upset the SD system too much? I'd think that that would give you the bump you're looking for and those parts should be relatively cheap and easy to locate.

I'm honestly not too up to date with the SD system as I plan to convert my 87 to mass air.

No. Not with a stock SD PCM
The calculated air flow would be to far off for it to run correctly.
You could do heads, exhaust, but the cam and intake would pretty much have to stay stock.
Doing heads is really a waste, because the cam and intake are going to only flow what they did stock, better heads would just be underused by a lot.
Obviously someone who is sharp with this stuff could "burn a chip" and compensate somewhat, but then you limits are really fuel injectors.

 

[LILCBRA]

I just ran across this thread while searching for info, this may help too.

T

Thread 'Thunderbird 5.0L compard to 95 5.0L'

Sep 15, 2004

I have an 1987 thunderbird 5.0L engine, is it a roller ? as well what are the differences between this engine and the one in my 95 GT ??

Thanks
Travis.

• Travis95gt
• Replies: 9
• Forum: 1994 - 1995 Specific Tech

 

[Noobz347]

So, the EEC is non-HO SD?


If so... Fogettabout it.

I'm just going to leave this here so that I can find it again later.

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I vote for an X3Z if you can find [cheap], a Cobra MAF sensor, and 24 lb injectors.

That put you right square in the middle of the kind of RWHP you want to make. All you need is the intake, cam , and heads combo you like the look of.

 

[Mcmahst]

Well, when I pull the motor, hopefully in Feb, I’ll pull it apart enough to verify if it’s a roller motor (as I remember, when I checked I think JEGGs a few years ago, the replacement parts for that motor were roller cam and lifters). If it’s not, hello Explorer 5.0 replacement. I’m not gonna go through the horror of breaking in a new non-roller cam.