New motor combination suggestions??

[jdstang87]

I hope you experienced guys aren't sick of questions like this...just need some insight so that I can actually enjoy my car after it's all said and done! Redoing the interior now and the motor/trans replacement will be next so I'm trying to decide the best route.]

Long story short I would probably rarely go to the track with this car so it'd be mostly for street driving but I still want it to be real fast, at least 400 RWHP N/A. Torque would be a higher priority since it'd be a street car I'd be more concerned about low end than high end.

Need suggestions on motor type/size (stroker, windsor, etc?) as well as head/cam/intake combinations that would produce the best driveability for my goal. Also trans...leaning towards Tremec TKO500 or 600?
Thanks a bunch!

Adam

 

[Kdubslugga]

I would think 400 rwhp with no boost no nitrous and streetable would be tough but not impossible. Your obviouisly gonna need all the cubes you can get for a streetable 400 HP and no help. I say a 351 Windsor block poked and stroked to 408 should get you there. Plus you wanna talk about torque, thats your answer! Are you wanting to keep it EFI? I dont know what to suggest for compression ratio, because im a boost guy.

 

[reldla1996]

I hit 425rwhp with my combo of 369 big bore, 185 comp AFR heads, Holley systemax intake, and relatively small cam duration of 223/227 at .050 to get decent street manners.

 

[jdstang87]

Yes I plan to keep it EFI, I'll be switching to MAF from Speed density at the same time...Thanks for the reply!
What's a good place to look at for the 369 block you're talking about? Does it handle well on the low end? What trans do you have?

 

[reldla1996]

The block is a Dart SHP, bored to 4.155, and then matched with a 3.4 stroke crankshaft gives the 369 dimensions. Several companies advertise a 363 which is identical except for .030 less bore. A 347 or 351 would get you in the neighborhood for less, though the bigger bore of the aftermarket block unshrouds the valves somewhat better compared to a 4.03 bore. I stayed MAF. The bottom end is solid with the relatively small cam, the torque was above 400 ft pds at 3200 rpm where my tuner started his pulls. I went a little big on the headers at 1 7/8", which probably hurt the torque output a little, but it's not an issue. I'm still running the T-5, which everyone says I'm on borrowed time with. I certainly won't speed shift it....

 

[jdstang87]

ok cool! I was wondering where the 369 came from so thanks for the explanation. I'm kind of leaning towards the 351 option like you mentioned and maybe bore it out...but anyone know of people that have done it with a stock block or should I start out with an aftermarket block for extra insurance. I know it probably depends on what I want to spend but I'm not too concerned about that, I want it to last!

 

[reldla1996]

The factory 351 block is stronger than a 302 block, and should be fine for something in the 400 rwhp range. A lot of them are stroked...to add to the party.

 

[jdstang87]

Alright cool, because if it'll be reliable I may decide to go that route...pick up a 351 from a junk yard or something and build it up, just wanted to make sure the block would be strong enough!

 

[jdstang87]

As an update, and for more suggestions, I've changed my plan to go carbureted instead of EFI. I'd like to get a used 351 block, bored to a 408 (I think), with all new internals. Just need help with a decision on matching heads, intake, carb, and cam for best low end torque/street performance.

 

[ratio411]

Yep... If you want torque along with that much HP, and NA... You gotta go 408.

Since we are talking carbs now, not EFI, I am in my element.
I would run a Torker 351w myself.
I know many people wouldn't agree with me, but this comes from some experience.
You have 2 options IMO for an intake:
Weiand Stealth, an aggressive dual plane or the Torker, a mild single plane.
I guess I should ask if you are running auto or manual tranny, cuz that would make a difference in my choice.
Stealth for the auto, Torker for the manual.
The Torker will rev quicker and crisper, without sacrificing bottom end, working very well with a gearbox.
The Stealth will make slightly more TQ at the very bottom, and work well with a slushbox.

A 750ish vacuum Holley will work best with the Steath/auto combo, but will also work with the Torker if you need better economy.
If you are using a manual tranny and Torker, and your fuel budget is unlimited, this combo would make the ultimate power with a 750ish DP Holley.

You will want headers in the range of 1 5/8" to 1 3/4" primaries.
Some of this stuff depends on what gear ratio you are using, which tranny (stall speed for autos), as well as obvious considerations, like cam.
I am just going by your words that you want REALLY fast, NA, that is street driven only, and lower RPM range than a street/strip car.

 

[ratio411]

Heads are all about cubic dollars....
How much you wanna spend?

The low end is 69-73 stock 351w heads that have been worked over with all the goodies.
Once done right, these heads outflow many aftermarket heads.
The biggest drawbacks being the iron... they weigh more and handle less compression than aluminum.
You'd have to run dish pistons with these due to the iron material and small chambers.

The high end would be something like AFRs.
I would love to run a 408 with 205s, but you talk like you would like 185s better.
With the aluminum, you can run 1 more point of compression without needing to increase fuel octane.
Also, the weight loss would give you a couple of 'effective HP' in itself.
Rough formula is that 10# of weight added or lost is effectively worth 1 HP increase/decrease.
So losing 50# would make the car act like it had 5 more HP.

Edit:
If you want a flat tappet cam, and strong block, go with an early 70s stock block.
If you want a roller cam, you can use the 95 5.8 block, but it is a thinner casting.
I haven't heard any stories on strength, good or bad, for the roller 5.8 block.
I have one that the previous owner put a rod through the cylinder wall, and it looks thin.

The early 351w blocks though are brutes. I have only heard stories of them breaking with 700+ HP!
So you have to decide on your preference of cam vs strength.
That said, if you are only talking 1 HP per cube, I doubt very seriously that the roller block would have trouble with that. The roller block is worth it IMO, as long as you stay NA.

 

[jdstang87]

Thanks for all the info! Got the stock T-5 now and I am going to stay with a manual trans...possibly a Tremec. I have long tube MAC ceramic headers that are 1 3/4" so hopefully that will be good. As far as gear ratio, I've got 3.73 right now but I was thinking of going to 4.10 when I do the 5 lug swap and all. Is that Holley 750 a 4 barrel carb?

 

[jdstang87]

The AFR 185's wouldn't be too much restriction on 408 cubes? Would the heads need to be port matched or anything with that Torker intake?

 

[ratio411]

Thanks for all the info! Got the stock T-5 now and I am going to stay with a manual trans...possibly a Tremec. I have long tube MAC ceramic headers that are 1 3/4" so hopefully that will be good. As far as gear ratio, I've got 3.73 right now but I was thinking of going to 4.10 when I do the 5 lug swap and all. Is that Holley 750 a 4 barrel carb?

Yeah, they make Holleys in all sorts of CFM sizes. There is a nice vacuum 4v Holley called the "Street Avenger" that is available in 570, 670, and 770. I haven't had one, but have driven Fords with them, and they seem good.

I would caution you against building an engine with such high levels of lower RPM power and then using a very low gear in the rear end.
A low RPM engine with low gears will not stay in it's power range long enough, especially in a light vehicle.
I ran a high RPM 302 in a car with 4.11 gears, then swapped in a stock 351c 4v (a high RPM engine as stock engines go), and it felt like I was driving a dumptruck. It was always revving past it's power band. The car weighed less than 3000# too, and that didn't help.

 

[ratio411]

The AFR 185's wouldn't be too much restriction on 408 cubes? Would the heads need to be port matched or anything with that Torker intake?

The only reason I said you sound like you'd want 185s is because you are wanting to keep the RPMs down for streetability.
I don't think they'd be a 'restriction' at all, but rather a calculated measure to keep port velocity high.
The 351w iron heads I suggested would be borderline restrictive, but still not a huge liability if you were looking for grunt.

 

[ratio411]

Another consideration on gears is tranny.
If you are running power that is pushing the limits of your transmission, you will make that problem worse with lower gears.
Make sense?

Purely as an example:
If you put 4.10 gears behind a certain tranny, it will be under more stress than that same tranny with 3.55 gears, therefore it could break quicker. Almost the same reason that Ford rates T5s with higher first gear ratios as stronger than T5s with the lower first gear ratio. It's all about leverage, and how strong the lever is.

If you have a stick that you are using as a lever, and it is 10' long, it has great leverage, but will break easier.
If you use a stick that is 5' long, it won't give you the same mechanical advantage, but it will be stronger.
The 10' long stick would have to be twice as thick as the 5' long stick to move the same weight without breaking.

 

[jdstang87]

Ok, yeah that does make sense. So the 3.73's would probably be the highest I'd want to go for the best driveability with a manual tranny? I don't have a problem spending money to do things the right way because this is my first project that's not a tractor! HA But if I can find a good 351W block and build it up with cheaper heads that would be nice...of course I may go with aluminum just for the weight loss
On a carbed set up with these kind of fuel needs would it be best to have an electric boost pump right out of the tank with a mechanical fuel pump on the motor? I want to make sure I don't run lean because my brother in law burned his foxbody to the ground because of that...of course I know that has to do with the carburetor being tuned right and everything as well.

 

[Gearbanger 101]

As an update, and for more suggestions, I've changed my plan to go carbureted instead of EFI.

Big mistake IMO. You want it to be an enjoyable ride, that rarely see's the track, you don't take a step backwards and install an archaic carburetor on it. Stick with the EFI and save yourself the headaches.

Why the hard on to stay N/A? Have you ever thought of any form of forced induction? You could probably build up a stout 302 based engine, with minimal hot rod parts, complete with blower that’ll spin the rollers to the tune of 400rwhp with a lot less cost and effort than building up a stroked 351W. And you’ll keep the front end weight down and the street manners and fuel economy to boot more reasonable to boot.

 

[jdstang87]

Being I have an 87 I would have to switch from speed density to mass air flow and it just seems like there are more things that you have to get set up in order for an efi system to work effectively...EFI is giving me a headache now so I don't know.
I'm not against forced induction, but it's just a high price to get started in that. I'm open minded.

 

[Gearbanger 101]

Being I have an 87 I would have to switch from speed density to mass air flow and it just seems like there are more things that you have to get set up in order for an efi system to work effectively...EFI is giving me a headache now so I don't know.
I'm not against forced induction, but it's just a high price to get started in that. I'm open minded.

I'll tell you right now.....It'll cost you probably close to twice as much to build up and instal a 351W based engine that'll make 400rwhp N/A, than it will sticking with your EFI 302W, convert it to mass air, add a set of junk yard Explorer heads and intake and add an entry level supercharger to the mix for the same result. Not to mention all of the time, effort involved in the swap. Nothing puts a damper on a project like sitting by the door, waiting for parts to arrive and hoping you didn't miss anything.