86 5.0L dangers with E7 heads?

93 LX · May 2, 2007

Are there any issues with doing a stock for stock E7 head swap?

Allen

poneypower89 · May 2, 2007

86 Mustangs dont have valve reliefs in their pistons... meaning, you could potentially have piston to valve clearence issues depending on what cam u run and etc.

Kingcater · May 2, 2007

Why would someone go thru the trouble?

85_SS_302_Coupe · May 3, 2007

Though i've never tried this, i am 99% sure you WILL bust your valves against the pistons...think about it...even with a stock cam, if the '87+ engines need valve reliefs for the stock cam, your '86 block doesn't have ANY reliefs for the valves, so it's GOING to hit the pistons....no matter what cam you use.

Cobra912 · May 3, 2007

Seriously it isn't worth the trouble. The amount you spend on a pair even if they are free or ready to go, you may need them checked or refreshed and will need new gaskets or bolts, it won't be worth it. My stock 86 5.0 verses a stock 93 felt like the same power. You won't see any kind of increase. Save your cash for a good set of Gt-40 or "P" irons if anything or save for the long run and get some aluminums.

93 LX · May 3, 2007

Thanks for the input. This was just something I needed input for. Main concern now it so get the car smogged so I can get the body of the 86 vert fixed and painted.

Allen

86bluecobra · May 3, 2007

I have never done it either but I have read that people have installed E7 heads on 86 engines with no issues at all.

As for why you would do it? You will be picking up 25 ponies over the e6's. It doesn't matter which head you buy you are going to have to check piston to valve clearence.

1987stangman · May 3, 2007

86bluecobra said:
I have never done it either but I have read that people have installed E7 heads on 86 engines with no issues at all.

As for why you would do it? You will be picking up 25 ponies over the e6's. It doesn't matter which head you buy you are going to have to check piston to valve clearence.

Your right. I used a 87' Crown Vic 5.0L in a Ford Ranger V8 swap project I decided to do. As you know the low po versions of the 5.0 have no piston valve releifs and an economy cam with standard firing order. I installed a set of E7 heads from a 92' GT on this engine and only saw minimal gains in power, not worth the swap at all. The only way your gonna get 25hp extra is to swap in the cam from a H.O block. I did this about a month after I did the E7 swap. You can use the stock H.O cam without any piston to valve clearance issues but you will if you go anything over this cam. I dont know to much of the 86' H.O blocks but I thought they did have valve releifs built into the pistons.???

Darkwriter77 · May 3, 2007

As stated, MANY lo-po shortblocks have been converted over to HO-spec by swapping heads/cam/intake from an HO motor. The '86 Mustang GT's EFI 5.0 was essentially the same exact motor as what they used in the Crown Vic/GrandMonkey cars from '86 to '91 and Town Cars from '86 to '90 - flat-top pistons with no valve reliefs, 16# injectors, speed density, a reeeeeally lame cam, and E6 heads ... although the Panther cars had the additionally restrictive different upper intake plenum (which was also reversed toward the driver's side) and cast-iron exhaust "logs" instead of tubular steel headers.

Lots of dudes over at crownvic.net have done the HO swap with no problems (aside from a crazy grin that can only be removed with plastic surgery). As I remember it, there are a couple of guys running E303 cams, as well, but I'm not 100% if they were still on the totally stock lo-po shortblock at that point or if they switched to notched pistons or an HO block - if it's on a lo-po, I think that would be pushing it to the ABSOLUTE limit of piston-to-valve clearance. I believe that even some minor valvetrain changes (1.7rr's, for example) can cause clearance issues, too.

As for "WHY?" ... puh-leeeez. It's a Fox Mustang ... 'nuff said.

LordMustangGT · May 3, 2007

I have a NON!! HO 5.0 EFI motor in my 88. Had to swap the cam to a stock HO cam to get the firing order right, Runs like a champ. No problems at all. You cam run as big as a E-303 cam with the 86 motors. I was running a F-303 in my 89 stock motor as well, no issues.

Matt

93 LX · May 3, 2007

The name plate on the engine says 5.0L HO and as I remember in my 82 Capri it has flat top pistons. I also have 19# injectors if the orange color means anything. Am I that far off the mark with this engine?

Allen

86bluecobra · May 4, 2007

93 LX said:
The name plate on the engine says 5.0L HO and as I remember in my 82 Capri it has flat top pistons. I also have 19# injectors if the orange color means anything. Am I that far off the mark with this engine?

Allen

actually the 86 engines do have 19 lb injectors as you stated. Thy wer H.O. motors with the H.O. firing order. There cams maybe less the the 87-93 cams however.

Daggar · May 4, 2007

I see a lot of crack smoking going on in here. Mostly concerning the cam in the 86.

The 86 cam IS an HO cam. As far as OEM cams go, it's one of the best (slightly more agrressive) if not, the best of the Fox cams (perhaps aside from the 93 Cobra cam).

Installing a set of E7s over the top of 86 flat top pistons with your run-of-mil head gaskets is hit or miss. I've seen (PERSONALLY) two motors take the swap with zero issues and one that required a thicker head gasket because the tolerance was way too close.

The E6 heads are pretty crappy when max flow is compared with the E7s. Do you really gain anything from the swap? That's debateable. The E6s make a little more bottom end than the E7s did. In the end, I doubt you'd find any difference in the quarter mile.

Stock for stock, I know I've never been walked by any 87-93 GTs and I ran that motor for a LONG time before installing the monster that's in there now. Compression and cam profile were two things that Ford used to try and make up for the E6 blunder. The heads aren't really that bad but they just didnt belong on a Mustang. I'd like to have seen something with the same valve angle and valve stem length in a better port and chamber design.

86bluecobra · May 4, 2007

Daggar said:
The 86 cam IS an HO cam. As far as OEM cams go, it's one of the best (slightly more agrressive) if not, the best of the Fox cams (perhaps aside from the 93 Cobra cam).

Good info. I wasn't sure if that cam had less lift or duration. The fact still remains that the e7 headed mustangs were rated at 25hp more then the E6 ones. The intakes are the same so I would be looking at the heads for the 25 ponies.

Daggar · May 4, 2007

86bluecobra said:
Good info. I wasn't sure if that cam had less lift or duration. The fact still remains that the e7 headed mustangs were rated at 25hp more then the E6 ones. The intakes are the same so I would be looking at the heads for the 25 ponies.

True but that leaves is with the age old question of swapping torque for HP.

Darkwriter77 · May 4, 2007

Lack of torque can me made up for with gears and/or weight reduction.

AOD86GT · May 4, 2007

86bluecobra said:
Good info. I wasn't sure if that cam had less lift or duration. The fact still remains that the e7 headed mustangs were rated at 25hp more then the E6 ones. The intakes are the same so I would be looking at the heads for the 25 ponies.

The intake on the 86 were slightly smaller compared to the 87-93 intakes. The Throttle body on the 86s measured 58mm while the 87s-up measured in at 60mm.

SVT32VDOHC · May 5, 2007

They will hit the pistons even with the stock cam!! Don't do it.

85_SS_302_Coupe · May 5, 2007

Someone correct me if i'm wrong (and i'm 99.99999% sure i'm not) but the '93 Cobra cam was the eventual '94 Thunderbird 5.0 cam (also the computer to go along with it) and SUCKED. It was designed for emissions since the car had GT40 heads on it. They used 1.7 rockers to compensate. I remember a popular mod for those Cobras was to swap in a '93 GT cam and computer.

86 5.0L dangers with E7 heads?

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