MX-Brad

My conversion has been on the road for a few years and about 10k miles. I'm pretty much at the point where I've shaken everything down and wouldn't mind upping the ante in the engine bay. The current engine is a novice freshening up. I've never had an engine apart before so I bought this used 5.0 and did rings and bearings and gaskets. It runs pretty strong but uses a fair bit of oil. I'd like to build a nice tight street engine.I don't have a budget in mind and won't mind spending some cash where needed, but I don't want to waste any money either. This is the plan in my head at the moment.
1) buy another used engine- tear down
2) send block in for hot tank and fluxing and possible boring and align hone
3) I would possibly have this shop build the shortblock, degree cam etc
4) with the shops help I would have to choose cam, and pistons, rods etc
5) I plan on buying a TMoss ported stock HO upper. (not the Cobra or GT40). I realise there are better flowing options but I really need this to stay under the stock hood.
6) not sure on what heads at this point...possibly AFR165? I'm using Martins headers, so I have to be careful to use something compatible.
7) Would be fantastic if all this could run nicely with the stock Foxbody EEC as it does now.

I'd love to be able to boast a 300+WHP build but that may be limited by my choice of intake. Am I on the right track? Also, I'm not totally adverse to assembling the shortblock myself since I have already done one. Degreeing the cam had me a little perplexed, but I've been watching some video's and I can probably handle that.
There is no rush on this...I'll probably do the build over the summer and swap it in next winter. Just planning and daydreaming for now.
Cheers.
Brad

.boB

New and built 5.0 engines are falling out of trees these days. They are professionally built, and ready to install. Generally speaking, they are available for purchase cheaper than you can do it yourself. It's not worth your time and effort to rebuild what you have. With a ready built engine on hand, the swap is almost a week end job. In some places, like Ford, the new engine also has a warranty.

engineer

Hi,

I agree with .bob.

Building it yourself is not cheaper, but is more rewarding.

Ok for a solid 300rwhp you will need...

331 or 347 cubes
Proper heads...afr 185 or trickflow 190 11r
Proper intake - trickflow fts r long runner
80-85mm throttle body
Cam with 220-224 deg of intake duration at 50 thou with 0.57-0.60 thou lift... Something like that from ed Curtis at FTI will do the job

Don't waste your time with the ho intake...its average...even after tom has worked his magic. It will choke the whole engine.

With the above you will likely hit 350-360rwhp and you can machine the intake, trim the hood and drop the subframe to make it fit under the hood...its really close but it can make it ��

If you are going to the trouble of getting the engine done, go the extra mile and you will not be disappointed.


Cheers

MX-Brad

.boB

There are a large number of shops that sell these engines. Even Ford still sells them. Like everything else, there is a large variance in quality. You can buy a ready made package with standard parts. Or you can call Mike Forte and have him custom build whatever you want. All depends on how much you want to spend.

Blue Print Engines is becoming popular with the Cobra crowd, https://blueprintengines.com/collect...-crate-engines . And, of course, there's Keith Craft https://craftperformanceengines.com/Category/FSM302 f you want more displacement, look at Ford Strokers, http://fordstrokers.com/fordstrokers-long-blocks

tbone heller

I got a short block from DSS 24 years ago that has held up pretty well. DSS Racing Pistons - Stroker Kits, Racing Pistons, Main Girdle

engineer

Hi Brad,

Yes you are correct there is likely a variance in the quality of crate engines out there. But realistically speaking for the majority of people who run their engines on the street at anywhere between 1500-3000rpm on average (and have a 6000 rpm limit) don't really have high end requirements (boost and NOS excluded). Any of the Keith Craft, Ford Racing, Ford Strokers crate engines will work just fine and they all come with warranty and some with verified dyno sheets.

You could of course build it yourself as it is not difficult, but it does require care and attention to detail, especially when things are not plug and play (i.e. cam thrust or crank thrust end float clearance too tight, Cam is out when degreed, piston to valve clearances out of normal range, deck heights too low or high, lifter bores are burred and drag lifters etc etc.). There is a lot to do but if you take your time it can be done and in many cases you can get an as good or better outcome than the current crop of crate engines.

But building it yourself is a bit of a hassle and will take time plus you wont save much money by doing it on your own if that's your goal, but personal satisfaction and a rich learning experience of doing it yourself however can be priceless!

A better approach for you (if you are determined to get handy with the build) might be to get a built shortblock as that is where the tricky parts of the build will be (clearances, bearings etc.).

You can then build up the top end to make it whatever you want it to be. Me personally I would opt for a stroker shortblock, its just easier to make power with more cubes and you don't have to do all the time consuming and dirty piston, bearing and clearancing work.

If 300 RWHP is your goal, I can attest to the fact that a 5.0L can get to 300RWHP but a stroker setup makes it so much easier and will drive a lot better with the increased torque. Its just not quiet as smooth as the 5.0L from a vibration perspective, but its only very slight.

But whatever you do (5.0L or stroker), use aluminium heads (AFR 185 or TFS 190 11R) and a proper intake manifold (i.e. the Trickflow R long runner intake with 75mm TB opening for 5.0L or 90mm opening for stroker) and a custom billet steel camshaft with around 214-224 deg of intake duration @ 50 thou lift and 0.57-0.6 thou of lift. I am assuming that you will be street driving most of the time and in traffic a lot hence the milder cam spec recommendations. I would also recommend a custom cam as this is very important. It ensures that all variables of the car and your end goal requirements (i.e. smooth idle, power steering, power brakes, air con, wheel and tire diameter, gearing etc) are all taken into account. For the minor price difference it is definitely worth the effort. On top of that add a 75-90mm Throttle body (75mm for 5.0L, 80-85mm for 331/347 up to 500hp and 90mm for over 500hp).

What you want is an induction tract from TB to intake valve that will flow 300cfm. The ford 5.0l factory setup is about 200-215cfm. This is where all the power is lost in the factory engine and gained by the aftermarket heads and intakes.

Also do NOT buy AFR heads and bolt on the HO manifold. If you are going to do that just keep the iron heads you have now as the AFR heads wont be able to flow any more than the point of smallest restriction (i.e the HO intake).

From my experiences I have used a TMOSS ported explorer intake on my 5.0L and on some of my older strokers. For a 5.0L the ported TMOSS manifolds are OK, not earth shattering but they are a definite improvement (intake tract flow goes from 210cfm to about 240cfm) with a decent head like an AFR 165 or TFS 170 11R you are in a decent position. However it is a far better option to just get a solid flowing manifold (and head) from the onset that can deliver the flow needed to make the required horsepower.

I prefer to have as much flow as I can in my inlet system so that I can make my cam as small as possible to meet my goals. The Off The Shelf cams mostly assume that the factory intake and heads are to be used, hence they have lower valve lifts (due to assuming weaker than required springs and losing engine torque in the process) and longer durations than required to get the result (thereby degrading idle in the process) . Hence my preference for custom cams these days..been down the OTS road many times...and was never fully satisfied for the effort involved.

As an example of how dramatic the end result differs when you do things in a not so good way..
I had the following many years ago..

331 stroker, TFS 170 heads, CompCams XE264 (214@50 with 0.55 thou lift) , TMOSS Explorer ported intake manifold and 70mm throttle body - Result was 283 RWHP (underwhelming for me considering the expense and trouble). I went looking for answers to my HP shortfall and found out that my intake flow was killing the car's power, the car's power curve was pretty much flatlined after about 4900 rpm. This was mostly the intake manifold causing this drop off.

After spending a lot of time with Dynomation (engine simulation software) and modelling my old setup and verified its deficiencies I went about modelling a new one. I arrived at a new more powerful configuration for that same engine but I needed to make a few changes;

I changed the following:

Changed Heads to TFS 190 11R - (Head flow went from 250cfm to 300cfm)
Changed TMOSS Explorer Intake to TFS R 75mm long runner - (Intake flow went from about 240 cfm to 300cfm)
Changed Comp XE264 Cam to custom Ed Curtis Cam 215@ 50 0.6 thou lift (very similar duration to old cam but with slightly more lift..)
Changed Factory 70mm Throttle Body to 75mm Accufab (TB flow increased from 680cfm to 924cfm)

From only the above changes the power moved from 283 RWHP to 333 RWHP (an 18% improvement). The difference in adding 20 odd percent in airflow is closely correlated to the same level of power increase.

This is an additional 50 RWHP (or about 60 FWHP) delivered with NO cubic inch increase , NO increase in engine MAX RPM, almost NO additional camshaft duration and NO loss of bottom end torque.

This was very valuable lesson for me in understanding just how dramatic the effects of a strong flowing intake system are to ensuring that the engine delivers its performance potential.

I could have done it properly from the beginning but I learnt the hard way...but you can benefit from my experience

Whether you go Crate long block, Crate shortblock or build it yourself, you have some time to plan and think about it before pulling the trigger. Whichever way you go for the build just make sure you keep us posted so we can all collectively give you as much of our experiences as possible to ensure that you can then make an informed choice for your "new" Miata.

Keep us posted in your dreaming phase as that is where all the right and wrong decisions are made

Hope that helps you..sorry about the lengthy rambling...!!

Cheers

MX-Brad

engineer

Hi Brad,

If the EECiV is custom tuned for the application (assuming the injectors are upgraded, along with maf and fuel pump) I cant see why not. Although the EECiV isn't super sophisticated it should run the car OK if custom tuned properly.

I run a custom tuned EECV on mine. It was tuned using an SCT tuner.

Cheers

MX-Brad

engineer

Hi Brad,

Apologies for my assumptions in my posts being slightly askew...I just realised that you are using the HO manifold and NOT the Explorer style manifold (hence my quoted figure of 240cfm for the TMOSS ported Explorer).

Yes for the HO manifold the TMOSS ported version will flow around 200-210 cfm.

Yes using the AFR or TFS 165 or 170 heads respectively will be perfect. But you will be leaving HP on the table with that intake. The Aluminium heads (either AFR or TFS) are quite a bit lighter and you will notice the difference (its about 70 pounds lighter across both heads).

If you plan on sticking with 5.0L in capacity and add a 70-75mm TB, a mild cam (214-218 deg intake duration @ 50 thou lift) and use 24-36 lb injectors @ 43psi. You will probably end up at around 230 rwhp.

Brad: Could you please measure the height of your manifold from the machined underside of the end rails to the top of the upper intake. I am curious to see what dimensions your installed intake has.

If it would be possible, you could even get a TMOSS ported explorer style manifold (about 240cfm flow) which will get a better result from the AFR 165 or TFS 170 heads. Say around 250-270 rwhp with cam and TB.

One of my older 5.0L combos was this:

TFS 170 heads
70mm TB
TMOSS ported explorer
214@50 cam with 0.5 lift
4-2-1 headers

This combination made 258 rwhp and the cam was very very mild. With a better cam (i.e. XE270) it was likely good for 270 rwhp.


A 331 Stroker with AFR 165/TFS 170 heads, 70-75mm TB, a mild cam and the ported TMOSS explorer intake will get you around 285 rwhp.

Any more HP than that and you will need a much better intake and or heads to get the numbers...

Also just for the record, you could simply perform a very mild "power bulge" enlargement on the hood as I had done to get you the precious 1/4 inch needed to clear any intake. That would not be very expensive either. Hardly anyone notices mine has been modified (see pics from my build thread)...but 1/4 inch is all the difference in the world for these cars lol.

In essence at best a 5.0L with a ported intake will get you 260-270 rwhp...a stroker around 285 rwhp (but much more torque). That is with both combinations being very very streetable as daily drivers.

Let me know your thoughts....

Cheers

MX-Brad

engineer

Yes it is a straight bolt on

jrmotorsports55

You may have to adjust some vacuum lines, otherwise pretty much straight forward. I have the Explorer setup on mine, and had the lower milled 1/4" for clearance. I run Ford Racing valve covers, so that added a few other issues I had to address. Stock valve covers should be fine with the milled lower.

MX-Brad

jrmotorsports55

MX-Brad

jrmotorsports55

Explorer has 70mm opening, good to go there. I have a few EGR spacers on mine as I had to push the TB out to the side more to clear the valve cover with the throttle linkage (ford racing covers and milled lower). I went with stock 93 Cobra MAF and ECU for 24 lb injectors to up my fuel game. I have TFS Stg 2 cam with TFS heads and 1.6 rockers. I had to get a silicone elbow and trim to fit with small cone filter for MAF, but it fits. Pics in my build thread.

engineer

Yes, I concur, + 1 from me.

The 70mm TB opening for the Explorer intake is there (actually I think the opening is like 68mm...so a bit of work with a die grinder will help...or at least it was on mine). The stock 93 Cobra MAF and 24lb injectors will give decent control until about 275 RWHP. After that a move up to a Ford lightning 90mm MAF will be needed for proper mapping control (wiring and plug is the same). The Cobra MAF will flood at 275RWHP (i.e. voltage signal to ECU is pegged at 5V) and after that the ECU gets no more understanding of increased airflow post that point. Also the 24lb injectors will be at 90-95% duty at 275 RWHP. I would step up the injectors (32 lb or more...I run 39lb Ford Racing) and the MAF (90mm Ford Lightning) if the target RWHP is over 275 RWHP. Its just safer and easier to tune properly with a bigger MAF and injector setup.

Cheers

MX-Brad

MX-Brad

Well, a FRPP Cobra upper and lower just came up for sale on a nearby Mustang club classifieds. I had first crack at it and after seeing pics of what looks to be a near mint pair, I e-trans'd a deposit. Will probably go pick it up sometime next week. Maybe I'll get lucky and TMoss will have already had at it.)
I'll have to make a spreadsheet of all the parts I need to gather. Cobra TB and MAF next I guess.

MX-Brad

jrmotorsports55

You need the matching MAF and 24 lb injectors, as it is programmed for those components. Otherwise a direct bolt in. Swapping to Cobra ECU and MAF solved all my bad running issues when I was running the A9L with Pro M MAF for 24s and 24 injectors, MAF was sending lean signal to ECU, so it was running pig rich to compensate. Runs great now on the Cobra stuff. Needs to be from a 93 Cobra.

engineer

Great work on securing the intake. You won't be disappointed.

Also on the tune, I would strongly advise to have the car custom tuned once it is running. It will make a huge difference in drivability. Easily done by a good tune shop.

cheers

MX-Brad