Opinions and guidance wise ones lol

[Soul]

I basically hate carbs, I don't understand them and my dad has to help me constantly. I do understand Fuel Injection, I'm gonna do the 87-93 mustang swap. My question is will it support my power now with factory Fuel Injection. I plan on getting a PlugnPlay megasquirt kit later. Any concerns, comments, or other items to consider? I came here as you guys are about the friendliest and most helpful board I'm a member of lol.

[Soul]

Also I have an HEI distributor, how is that going to play with everything?

[MalcolmV8]

I know it said guidance from wise ones but I figured I'd jump in anyways What power levels are you at? I guess that'd be the first thing to know. Also what mods do you have that affect power, such as cam, heads etc.

[cgrey8]

Over on the EECTuning.org site, there are people running upwards of 800hp on stock computers (with tunes of course). And if the only thing you care about is racing down the strip, a stock tune can be setup to do that. You won't have a good idle, driveability will suck, but the WOT-blasts will be right without a tune. But for a strip-only vehicle, that's often enough.

However for a street vehicle, you need something with a lot more manners. And so what the stock computer can and can't do is more a function of how far from stock you get. If you only bump up from 19lb injectors to 24s to support ~300hp, the difference is minimal. However if you are pushing the 24s to their limits or you are producing in the 400hp range and thus need injectors in the 30s, then that's where tunes become a necessity for a civil driving experience. And pretty much any boosted application is going to require a custom tune to deal with since the EEC is not setup, in stock form, to properly handle Loads above 100% (positive pressures on the intake manifold).

Most of the problems people face after doing mods to their engine are with fuel leanout, idle instability, and spark control that causes ping or lack of power. And then there's the occasional emissions requirement from those that live in areas requiring inspections. Many of the problems with "calibrated" MAF/Injector combos is they are fibbing to the computer the amount of air that is flowing so the computer will squirt the injectors by the same amount less since the injectors are also larger than stock. But because the EEC is being lied to, the result is that the EEC's calculation of engine Load is now inaccurate so everything associated with Load in the calculations is OFF...things like spark tables, EGR tables (if not disabled), and Open Loop Fueling AFRs. This is even more of an issue if your EEC also controls your transmission. With the EEC believing the engine is always under less load than actual, the EEC never commands enough line pressure for the transmission and thus shifts are softer than they should be which can burn the transmission up faster than if the EEC had been tuned correctly.

The #1 thing to be aware of is not to oversize the cam. Cams get the same pathetic selection benefit that carbs do. People always choose the bigger one when the smaller one will serve their needs far far better with little to no sacrifice in power. Injectors used to be a place where people would commonly oversize and they actually still do. The good news in that area is the new generation Injectors are so good that you can grossly oversize them and they still function accurately at low demand conditions to work well in undersized applications.

So all that being said, what are your engine mods?

If you do require a tune, are you at all interested in tuning this yourself? If so, you'll want to read this about EEC tuner/dataloggers:
Things to know BEFORE buying a TwEECer or Quarterhorse

I know there's a few people on the EECTuning forum that have dealt with HEI distributors. But the vast majority run TFI since TFI with an ignition box works quite well and is reliable. With an ignition box, the TFI module isn't electrically loaded like it is when it is supplying the current to the coil in stock form making their job 10x easier so they don't generally burn out when connected to ignition boxes.

[Soul]

This is the 331 stroker I built on here, afr heads, Can't find my cam its the xr series one that Chris suggested, 1.7 roller rockers, and HEI distributor. Also running fuel manual C4. It would be doing the fuel and timing for motor, no shifting. I would like to put this on and get the PNP kit from megasquirt. Oh and best guestimate was 440-460 hp range.

[cgrey8]

Do you have more specs than that? For example:

• What are the head combustion chamber CCs?
• What are the piston dish CCs?
• Head Gasket thickness
• Piston-to-deck clearance (how far in the hole or popped are the pistons)?
• Connecting rod length (usually 5.4" or 5.315" for 331/347 although there are some oddball kits that use the much shorter 289 rod lengths)
• I don't know what cam an xr is. Although I have recommended a few different Comp XE cams. The exact number is important though.
• Do you have a timing chain set that lets you adjust the cam timing?

I ask all this because I would like to run it through this simulator and see if you could benefit by retarding the cam a bit, if anything for safer running on pump gas.

[Dave]

Soul,
You have your engine build in so many threads, hard to keep track of. Remember you are running a gear set-up like Mark, your cam is the XE264HR-14. I wish I knew what the timing was at .05 lift, that's the same cam I have. Your cam in the package below.
Dave

[cgrey8]

Comp XE264HR14 specs:
212/218@.050"
264/270@.006"
.512"/.512" lift w/1.6RRs
Intake Center 110
LSA 114

For most any street application, that's an excellent cam. You can't hardly go wrong with that cam. That doesn't mean this is the magic cam that is the answer to all street builds. It just means that this cam serves most all applications well giving both good idle, decent low end torque, and plenty of HP at the top end. Obviously custom cams will always be able to pick up pieces an off-the-shelf cam isn't. The question you have to ask is if the extra 5-10hp is worth the cost of a custom grind vs an off-the-shelf stick.

What exhaust mods do you have? Shorty Headers? Long Tubes?

Making a lot of guesstimates about Compression Ratio, heads being AFR185s (not AFR165s), 1.7RRs, this cam, and real Headers with mufflers, this is what it simulates at:

___________________

Edit. I updated the pic with info that was posted later in the thread.

[Soul]

Comp XE264HR14 cam
Piston Head Volume (CC) -4.0cc (flat tops)
Connecting Rod Length (in) 5.400
64cc chamber 185 afr heads.
Head gasket is Felpro, not sure which
1.7 rockers
Full 1 5/8 primary equal length headers that dump at 3" with summit mufflers on it 2 1/2" exhaust

Sorry would of replied sooner but had to go to a meeting for "displacement", ie we are being let go, knew about it already so not a big deal.

[Soul]

Ya really sorry about it being scattered, I was hunting it up.

[cgrey8]

Do you know how far in the holes the pistons are? Or are they zero-decked?

BTW, I updated my post above and pasted in the latest simulation based on the new info you indicated that was different than my assumptions. Compression Ratio changed a tad and power went up because I calculated using long-tube headers.

Based on what I've gotten into the simulator so far, it seems you make some pretty big HP number improvements when you retard the cam by 4°.
Check it out:

Souls_331_comparison.jpg (55.82 KiB) Viewed 3922 times

As you can see retarding the cam 4° extends the torque curve to maxes HP at 5500 but holds that HP right to 6000RPMs as well as boosts the HP numbers by a HUGE amount compared to the cam installed straight-up.

Now what you don't see here is the trade-off when you retard the cam. The off-idle torque will drop some. It's not going to be massive, but it will be a drop comparatively speaking. It only begins to drop off at 2000RPMs in the simulation. But just like the gains take off around 4500 as compared to the cam installed straight-up. The same will happen with torque fall-off from 2000 down to idle.

I guesstimated at your dynamic compression ratio and it's in the 7.8-8.0DCR range which means you should be just fine to run regular pump gas. If anything, you'll only need midgrade. As long as you have a 1/2 way decent quench, you shouldn't need premium. Retarding the cam makes it even more tolerant of regular octane.

[Dave]

Chris,
I just knew you'd enjoy having that program to play with! Really intersting for those with inquiring minds. You did enter in the value of 500 cfm in the first version, is that about what the Explorer set-up is rated at? Not going camping this week end I hope. Stay home, stay warm and stay safe.
Dave

[cgrey8]

Explorer intakes in stock form support up to 325hp. When the lower is ported, they can handle upwards of 400hp. A 325hp N/A engine is usually pulling down about 800-1000kg/hr of air which translates to ~500cfm. So that's a fairly safe setting to assume.

And yes, the weather ruined our camping trip. We realized it would be cancelled yesterday morning and the forecast didn't get better. It's raining here right now pretty hard and will continue to into the night. Hopefully we won't have any tornadoes.

[Soul]

Well sad face that I'm not making as much HP as I was thinking / hoped, Big grin @ My compression is lower and I'm doing a blower lol.

[cgrey8]

Keep in mind, the simulation numbers are not to be taken literally. The only thing simulations should be used for is to gauge trend differences in components. I guess you can say the simulations are accurate enough to tell you ballpark HP/Tq value expectations. For instance, if you thought you were going to be in the 400hp range with this build in NA form, then yeah, the simulation is showing you that 400hp is unreasonable. But if you were expecting 10-15hp more, that's not out of the realm of expectation although I suspect simulators are a tad "optimistic" with their numbers.

But yes if you are planning on boosting this engine, be glad that your compression ratio is reasonably low for doing that.