Edit: reference to a E6TE head are a mistake. As pointed out here later, we are discussing a E6SE
head.

Hey all, got a head question. I have a 1986 F150 5.0 EFI AOD. Original owner and 130,000 mi. The engine is coming out for a rebuild. I am not seeking any more power at the expense of fuel economy. Happy enough with my 33 yr average of 14.9 mpg. After reading a hundred threads and articles on the 302 heads, I have to wonder about my E6SE heads.

If these heads are truly bricks as 90% think, (a few seemingly knowledgeable commentators like them) would it be possible to produce more power (torque) AND improve fuel economy? Since I rarely, if ever, see any elevated rpm, it doesn't seem that I would see much benefit in improving the heads.

Considering switching to roller top end if I can find a decent doner with MAF that I could easily adapt to my current, quirky MSD. If I did that, I would be shopping for a torquey cam that might still preserve economy. Of course this added expense could never be repaid in fuel savings but might possibly weigh out OK in enjoyment.

I keep reading and getting all these great ideas but at the end of the day, I think reusing the E6s is the smart move.

Seems Ford produced the E6SE and used it only to get rid of stock on hand. They went to the E7TE after one year and liked it well enough to use it for nearly another decade. On another subject, seems they didn't much like my trucks intake manifolds either.

 

The kidney bean combustion chamber shape of the E6 heads was an attempt to induce swirl action and better mixing of the intake charge for a more even burn and better torque, and at this these heads excel. The problem is they made the chamber much too deep which heavily shrowded the valves and totally crippled airflow, I ported the blazes out of a set of these and max airflow still fell well short of what untouched E7 heads do. A version of this chamber design appears on some of the best performance heads today(trickflow) but the chamber is much shallower with the chamber walls laid back so as to not impede airflow.
If you want to have a go at improving this head I suggest taking a cutter to the massive smog bumps in the exhaust ports and cutting them completely down flush with the roof of the port, then smooth and shape the bowl area of the port right behind the valve and also open up the port as much as you dare. Also smooth out the surface of the combustion chambers and remove the sharp edge where it meets the head gasket surface, I'd suggest doing similar work to the intake ports but even after all this work the exhaust side will still be a bottleneck so don't waste your time. With that done the motor will take more ignition advance and with a high lift short duration cam the motor will make much better torque which should translate to even better fuel milage.

P.S. What gearing does the truck have? A 5.0/AOD truck can get upwards of 20mpg with just the right combination of gears and tires but it might surprise you that the optimal gear ratio is higher numberically not lower.. in the range of 3.55-4.10.

 

Thank you for responding about the heads and also for bringing up ideas about gearing. Your comments on the gearing set off fireworks in my head.

I should have prefaced this thread with a few more details. My goal is to have a reliable daily driver. Thirty-three years and 130,000 miles suggests this truck doesn't get driven much. It doesn't. Consider also that it had 50,000 miles in the first five years. Only 10k since I took over my wife's '97 Riviera as my daily driver in about 2008. However, the plan is to retire the Riviera (bought new) and have only one vehicle, excluding motorcycles of course, in my garage. Daily driver, yes, but also my only driver. My grand plan is to drive it "until we don't burn gas anymore". So, we are really looking at the long haul here.


Back in February of 1986, I recall that I was totally impressed with the 5.0L EFI. Huge power gain over my 1970 C10 w/ 307 ci V8. It's why I chose to buy the "newfangled EFI" 5.0L in it's premier (full) year of production. Regarding gearing, the truck has a 3.55 rear end but I went from 215/75R-15s to 30/9.50s in year one. (10% higher? 5mph difference on speedo at 55 mph) I now remember thinking the tires were a good fuel economy move back then. During the last 19 years though, I wasn't sure that this gearing was helping much since I never took it on a road trip anymore. My thinking (flawed?) is that lower gears are better around town. It used to get 19 mpg on the interstate while hauling up to a half ton of motorcycles. Annual winter trip to Daytona Bike Week. I don't believe the truck has ever been on a road trip unloaded. Power wise, the seat of the pants impression evolved to the point it felt like the truck was struggling. When I retired in 2013, I told the truck (not out loud) that it was going to retire too. I switched back to 235/70R-15s, the same OD as stock. The truck did seem to appreciate the lighter load.

My own thinking is that I really want to use my E6TE heads. The reason is simple. They are the heads that I have. I could do the porting work since I have some experience and the tools to do it. But then, due to the E6's inherent flaw, it would help very little. Staying with the E6 means staying with the stock cam and flat tappets. If the E6 is truly a bad choice, then the next lowest cost alternative would be the E7TE along with the stock cam and tappets. Taking only that step would not not add much to the cost of the project. That step would be pricier if I went for E7TE heads that already had all the roller hardware. (Good chance roller hardware could be fitted to my block.) As I alluded to in the original post, going this route would not be a deal breaker cost wise if the benefit were there. So, we are really looking at the long haul here.

Side note: Alternatively, with the cost of a decent, newer, low mile F150 as a replacement being north of 30 grand, I have lots of room to spend more on this project if necessary.

Getting back to my current set of heads, I do have reason to believe that they are in very good condition and will require minimal work. This assumption comes from the consultation I had with the machinist. Always timely oil and coolant changes. Never once overheated. We are expecting the bottom end to need a .030 bore and likely only a crank polish. Of course, all bets are off after disassembly.

Ski, you talk about cam profile. High lift and short duration for torque. This conflicts with my long held notion. I am in no way learned in the aspects of cam profile, never have been. My only experience whatsoever was when building my EVO Harleys for power. My guru was Carl Morrow of Carl's Speed Shop. At that time, I didn't need to understand the theory of cam profile, he did that for me (and anyone else who had the since to listen to him) His mantra was build a rider for torque, much easier to enjoy on the street. He said one byproduct of building for torque was more horsepower. His custom ground torque cams were not shaped like any of the high horsepower cams most guys were foolishly throwing at their bikes. They were a modest .490 lift compared to .473 stockers but with a quick open/close and longer duration. Most HD horsepower cams of the 80s were in the .550 and up range and very pointy. Thinking back on it now, the high horsepower cams probably had the long duration but just looked pointy because of the lift. I have not yet begun the leg work for cam selection other than what it might cost. I have merely assumed any roller cam will cost about the same to install. I have imagined a cam that is like one step up from stock but one step up to the torquey side.

Thanks again. Your comments are helpful and appreciated.

 

The E6 heads were not a one year deal. Ford used them up until 1991 in the big cars. And in some trucks too. You can switch to E7's with the stock cam profile, but you can't go more aggressive on the cam without swapping pistons to ones that have valve reliefs. The valves in the E6s are located higher up above the deck than all other SBF pistons this is why they have no valve reliefs in the E6 headed 5.0's

 

"The E6 heads were not a one year deal. Ford used them up until 1991 in the big cars."

Glad I came over here to have this discussion. And with all the reading I have done, I still did not know this. The fact that Ford didn't dislike them as bad as I thought goes as a plus in the E6 column.

 

They made more bottom end torque than the E7's but 25 less HP in the upper rpms. The 86 Mustang's had them and turned quicker E.T's in the 1/4 mile than the 87's did. Those were Ford and other's findings I found in Ford's "Official Mustang 5.0" book published by Ford Racing.

 

Cam duration factors into P-V clearance too so it's not likely there would be a problem with the relatively small EFI friendly cam that will get suggested. This motor has the base cam in it which is hilariously small and restrictive producing only 240 deg duration seat to seat and 0.390" total valve lift with the factory 1.6 rockers. I have some pics somewhere of the intake valve in the E6 head at 1/2" lift and only about 1/3 of the valve head sticks up above the gasket surface. The cam I'd suggest is the Comp 31-255-5.. 31-255-5 - COMPUTER CONTROLLED Hydraulic Flat Tappet Camshaft for E.F.I.

 

You're right, I was thinking on the 86 HO motor, but then again the B303 roller cam was originally designed for the 86 HO motor as well. Where you get into trouble is changing heads AND cams without addressing the flat topped pistons these motors came with

 

Okay, I clicked on the link. I have now looked at my very first cam specific web page of this project. Now I have a whole lot more questions. First question is about the original subject matter, the heads. Could a cam like this be "dropped in" my otherwise stock engine? Should I? Will all my old studs and rockers be happy with this cam? How about the old valve springs?

Looks like one of the deals where it might be prudent to "go ahead" and replace other components. A new cam should have new lifters. No?

Thanks to both of you for taking the time.

 

A new flat tappet cam must ALWAYS use new lifters. Roller cams ? You can reuse old lifters. You would be worlds ahead changing over to a roller cam here.

 

Been looking in the linked website for an hour. Closest roller cam specs to the above recommended flat tappet cam are a bit more aggressive. 35-308-8. From what I am hearing, seems both of these cams would do really well making a lot of torque early even with the E6TE heads. I also think I'm hearing that they would hit a wall at some point. Sooner with the E6 vs the E7. Am I just imagining that the E7TE would be a better balance?

I really like that the flat tappet cam uses the words speed density, strong torque, excellent mileage and good idle in the description.

 

Actually I think the Comp 35-512-8 is closer but the cam I think would be the best is the Crane 364211, only problem is the price. And speaking of cost, do you know yet if your block is roller ready? If it is you could use a junkyard spider/dogbones assembly and OEM roller lifters which are relatively inexpensive, but if the block isn't roller ready(raised bosses to mount the spider and taller lifter bores) then you have to use aftermarket link bar roller lifters. With pushrods this roller cam setup will cost 2-3 times what a flat tappet setup costs, and as much as I like the idea of a roller cam you have to ask yourself if it is worth it in this case. If you were starting with a roller motor that is a different story.

Yes, the motor will hit a wall at about 4000rpm with those heads while it could pull to 5500rpm with the E7s.. with the right cam of course.

Yes it is meant to produce stock like operation.

 

Enjoying my cam primer tonight. I did not know link bar lifters existed until tonight. My block should be roller ready, at least to the point of having the bosses cast. I have heard some cases of these early roller blocks not having the bosses formed well enough but I think that is uncommon. I won't know for sure until I tear it down. I may need to drive the truck for another week. My brother is dropping in and I typically give him the Riviera to drive during his visits.

I have absolutely now learned the cost difference between the flat tappet scenario vs roller. I also see Comp Cams would be happy to supply roller rocker arms to complement the flat tappet cam. Speaking to my "drop in" question, we have established that along with either cam I am buying new lifters. I had already assumed that given the nature of the cam / lifter interaction. But would new rockers and pushrods benefit the build?

EDIT 08/20/20: Way late in the game to have to find this out. The Crane 363211 cam has a slightly smaller base circle than stock. But never fear, for a mere $150, Crane offers a .052" longer pushrod.
In summery, to convert a roller ready 5.0 to a Crane 364211 roller cam using new parts.
Cam _________ $400
Lifters ________ 125
Spider kit _____ 75
Pushrods _____ 150
$650

 

If you go with a roller cam you must buy new pushrods because the pushrods you have will be too long... roller lifters are taller so the pushrods have to be shorter. If you stay with a flat tappet cam you can use the pushrods you have.
Full roller rockers reduce friction in the valvetrain but it's a relatively small amount compared to what a roller cam does. I think roller rockers would be wasted on the E6 heads and there is no benefit to new stock rockers at all.

 

Yes, I put a Comp 35-349-8 in an otherwise stock '90 truck 5.0 and it ran like a scaled cat.
Oh yeah, on these early EFI motors a cam change is the single best engine performance upgrade you can make.
Yes.
Yes with a qualifier. Stock E7TE springs can "handle" somewhere around 0.520" lift before coil bind, I seem to remember something about the exhaust springs on the E6 heads being shorter so that is something that should be checked. All of these stock springs however are just barely adequate in terms of pressure for 5000rpm operation so it's never a bad idea to upgrade them when rebuilding.