69GTOby

I know this isn't a boat forum, but I could use some tech advice and this is such a lively, vibrant, fruitful SBC forum. I have an '88 Baja with a 350 Mercruiser, aka Chevy. It's a little different than a car engine. I think it has a flat tappet and swirl port heads. It's rated at 8.8 CR if I remember correctly, and 260 HP.

It's a little hard to start, smokes during start-up, smokes when revving or when planing, especially when pulling a skier. It runs real smooth and will go 60+ MPH, but it's got a rough smoky idle. I hooked up a vac gauge and get a rapidly vibrating needle at like 14"Hg.

I am thinking at least valve seals, but it could probably really use a whole valve job. I think the shaky needle is indicitive of worn guides. I tried to tune it out (plugs, wires, cap, rotor, tuning, timing, etc) but can't get rid of it. This of course leads me to thinking about a head swap and getting those lower CR crappy flowing tired heads out of there. I was thinking Vortec, 305 HO or even aftermarket.

I am thinking I can get some Vortec or 305 HO units for a few hundred bucks, used but in good shape, or new Summit (Trick Flow) for about a grand for an assembled pair (which is amazing btw). My understanding is the Vortecs or aftermarkets will require a new Vortec bolt pattern style intake, which isn't too bad for 150 bucks or so. It has a new q-jet by the way. I am a bit worried about the 305 HO heads being "thin walled" and not heavy duty enough for marine use. I'd love to splurge for the Summit aluminum heads, but am hesitant to spend the money as I just bought a house.

Basically, my head is kind of all over the map here. I have never done a head swap on a Chevy (yet) and I could use some good input, especially since this is a marine environment with some different loads and operating conditions than a car.

There's no water in the oil, compression is 165 or so in all cylinders, it still looks like new on the outside. And in in attempt to fix this issue, I resealed the intake and it looked new inside too. The oil is always nearly clear and full. I am pretty confident this is a top end issue, and the bottom end is still strong.

Hopefully I don't get my head bit off for posting this on a F-body forum.

Damon

I've worked on quite a few old 350 boat motors so I know what you're saying. Yes, the heads are probably toast. Guides, seals, the whole shootin' match, since you've already tried fixing it by resealing the intake.

Here's how I fixed all of them: I bought a new L31 Vortec long block, a matching Vortec carb intake, and I installed them reusing the existing carb (probably QJet), Mercruiser distributor, etc.

NONE of this stuff is rated for "marine use". Doesn't freaking matter. Marine use basically means "please pay twice as much because we say so". You know how marine heads differ from automotive heads? They use larger diameter valve stems because of the extra heat that's generated by a motor that spends more time under heavy load. So they use big, fat, heavy 3/8" stems instead of automotive 11/64" stems. Difference in longevity? Maybe 20%. Do you care? Probably not at double the cost.

Is an automotive intake different than a "marine" intake? Yeah, the marine intake has some sort of coating inside the coolant passages that prevents crud from building up inside it. Does it matter? Not a heck of a lot. If you flush with fresh water after each use, I can't imagine this being a problem for a long time. Still nervous? Buy a Mercruiser Vertec-style intake and use it (or a nearly identical Edlebrock marine intake). Just don't complain about the cost if you do.

Moving up to a Vortec head from those old pre-Vortec turds usually results in the next problem.... asking if there's a steeper prop you can install to load down the motor to keep from over-revving the engine when you're at WOT and have it all trimmed out, sitting on top of the water with the tach swinging WAY too far to the right.

Apples to apples, I've seen this upgrade take 45 MPH "family cruisers" and push them up in the 55 MPH range with the right prop. There's nothing like walking right past JetSkis in a 21' Regal with a Bimini top and watching the wake disapppear aft in a nearly straight line. You kinda have to readjust your brain and ask "this is a family pleasure boat??"

The 260HP rating on your existing motor was optimistic, even when it was new. The 275HP rating on a Vortec motor is understatement. There's probably at least 50-60HP difference between them in the real world.

Side note- do the whole motor at once. Yes, you could probably fix a lot of problems with just a Vortec head/intake swap but you'll probably kill the nearly-as-tired bottom end in short order after you do. You're gonna be leaning on it harder and probably seeing RPMs the old bottom end hasn't seen in quite some time, if ever. It's not going to like that. So bite the bullet and re-power it with all fresh stuff. Then pray your outdrive is still up to the task. Did I mention you'll probably break an old Alpha1 outdrive? Well, you probably will. Eventually. But you'll be shitting yourself giggling when you do.

Fast355

iTrader: (2)

Alpha1 came behind the 330 HP 454 in some boats. Keep it cool and keep it limited to 5,000 rpm and it will live a good while.

69GTOby

Thank you for the responses! Are you saying you buy a NEW L31 long block and swap over the top end? Or are you saying you buy a NEW L31 long block and swap the whole thing in and ditch the old engine? Either way, a new L31 sounds expensive. For that amount of money I could easily buy the pair of brand new aluminum Summit heads and the intake I need and still only spend $1300 at most for everything including gaskets and fluids... But, that's reusing the short block I have.

I am pretty confident the short block I have is in good shape. It ought to be. We hardly ever run it very hard and always change all the fluids and filters every season. I already rebuilt the outdrive twice. I did the impeller the first time, then did it again a few years later to do the u joints, bearings and seals as well the second time.

We had a 17P prop several years back. It would rev to 5k pretty easily with that. It was good for pulling skiers, but cruising speed was pretty low. Then I got a 23 or 26P... I can't remember, but it is overpropped now. WOT RPM with this one is a little over 4k, maybe 4100. So, this prop would probably work well with vortec heads and get the boat into the 4500-4800 WOT RPM area where it belongs.

This engine is flushed with fresh water DURING each use, LOL. It is a lake boat. We got a pontoon boat a couple years ago, so this boat doesn't get used as much. Maybe once a summer for skiing and just occasional cruising a hand full of times a year.

Maybe I have too much confidence in the bottom end, but I like to think it's still in good usable shape. It doesn't have that many hours, it's always seen fresh water, it was very clean inside, it has always been taken care of... Am I being terribly optimistic? Would a vortec top end surely blow the bottom end during the first WOT blast?

Even if I did have a couple grand or a few to throw at it, it seems wasteful not to use a short block that still has some life left in it... If it does. Of course, that's impossible to know for sure until it is torn down...

Vader

Just remember that you're stuck with using the flame-proof Rochester, which isn't actually a bad thing.

FWIW, aluminum heads aren't probably worth the cost or effort, and head cooling is usually not a problem with these anyway (unless you are concerned about over-cooling). Even with sacrificial anodes the aluminum will start to go away faster than iron, at least in fresh water. I know salt water is a completely different thing, and I have no experience with I/Os in salt water.

Damon

Yeah, replace the whole damned engine, would be my suggestion. It comes with all the little nitnoid parts you're going to need like a 1 piece RMS oil pan, the self-aligning rocker arms that Vortec heads require, centerbolt valve covers, etc. That nitnoid stuff adds up if you have to source it one piece at a time. And... by the time the heads on your existing engine are worn out, the bottom end is about 75% used up, too. Buy a Vortec long block, add a Vortec intake that accepts your Qjet carb ($150-200 new- see "Edelbrock Performer Qjet" intake- I think there's also a "marine" version of it offered) and bolt all your existing stuff on to it.

You can find a brand new GM L31 (automotive) long block for about $2000. If you go rebuilt they're in the $1300-1400 range. For example (just did a quick internet search):

http://www.powertrainproducts.net/ch...FYgYHwodx8YP3w

If you want to start with the heads and intake, that's fine, too. Just consider it a blessing if you get more than 1-2 more seasons out of the bottom end.

A lake boat (fresh water) is going to make your life easier. You still have electrolysis to deal with like Vader points out, but at least you don't also have salt water eating at everything on top of that.

Boat engines should be cast iron, all else being equal. I only mention using an aluminum intake because they're cheap throw-aways. If you eat one every 5 seasons (which would be pretty aggressive use), who really cares? Chuck it and put on a new one. Cost of doing business.

novaderrik

i have an uncle that works on boats for a living.. he's taken almost brand new marine vortec 350's out of boats that he's gotten cheap or free for one reason or another and sold them online for a few hundred dollars.. i don't know why people give away almost brand new boats with motors that have very little use, but he finds them..

Jonesyfxr

iTrader: (2)

Besides being a member here, I'm also a member of the Western NY Offshore Powerboat Association. We have some pretty badass machines. But as your question, as I'm building a little 355 for my 23 footer, I'd get a set of Vortec truck heads with the sodium filled exhaust valves. Most boats eat the exhaust valves because the engine runs a constant rpm over extended periods of time. My little 355 should be an easy 350hp when done, but a thing to remember........depending on your outdrive, you can only put so much power through it. Alpha's are weaker than Bravo's and so on.

Hope this helps.

69GTOby

It is really tempting to buy a whole L31 long block and swap it in, but, all things considered, I think I will go the route of rebuilding the top end. I agree that cast iron is more suitable to the marine environment. I especially wouldn't want to bolt up big, heavy, cast iron water cooled exhaust manifolds to aluminum heads...

I am on the market for some good heads and an intake to match it. What do you think of these heads??
http://washingtondc.craigslist.org/n...236194880.html
They are the same as these...
http://www.summitracing.com/parts/wr...make/chevrolet

Also, can someone please tell me what kind of pistons my engine has and what the head cc is with my current heads? I think it is advertised at 8.8 SCR if I remember correctly. Again, this is a 1988 350 260 HP Alpha 1.

My understand is there there are two versions of the swirl port heads: one with smaller chambers used on cars (65 cc) yielding about 9.3 SCR, and one with larger chambers (76 cc) used on trucks yielding about 8.5 SCR. I assume the boat got the truck head version... Is this all correct?

Fast355

iTrader: (2)

I have NEVER run across a 76cc swirl port. Most are around 65cc. The compression difference is in the pistons. A car had flat top pistons with 6cc eyebrows. A light truck had the normal smogger 350 piston with a shallow dish and 4 eyebrow reliefs for 12cc. The HD TBIs ran an even deeper dish with 2 trough style reliefs and 18cc total dish.

Flat Top


12cc dished


18cc dished piston

Damon

Agreed with Fast. 350 swirl port heads are all ~64cc chambers, to the best of my knowlege. Vortec heads are also spec'ed at 64cc (though, those who have measured them will usually tell you there are about 62.5cc in reality, if they have measured them).

Different engines got different pistons to alter the compression ratio. In a boat I'll bet you $20 real cash money it's got the most common of the three: -12cc dished with 4 valve reliefs.

Every 350 boat motor I've taken apart since time immemorial has had them.

TTOP350

iTrader: (8)

Only real difference I have seen between boat and car/truck motors is the coating used in the cooling ports of the boat motors. Its supposed to resist saltwater corrosion.
I have never measured the valve stems so I don't know about that.

69GTOby

Thanks! Great info on the pistons. Idk if I read it somewhere or made it up based on assumption about the two chamber sizes lol. Yea, I bet I have the middle of the road pistons in the boat. I know the CR on the label was 8 something.

I have never had much of a problem with corrosion since it's a freshwater use boat anyway.

I am definitely leaning towards just doing the top end for now. I know, I know it probably won't last. But, if any engine is a good candidate for a top end rebuild it is probably this one as the hours are relatively low, it hasn't seen heavy use, it has always been taken care of... I guess I'll take my chances.

Now, I just need to find a good set of heads!

Fast355

iTrader: (2)

I pulled apart a junkyard 8.1 out of a monster G3500 cutaway van based party bus this weekend. 80k miles of in-town driving, pulling around ~15k lbs and who know how many hours of idling. The only mechanical problems I have found are a cracked exhaust manifold, leaking intake gaskets, and oil fouled plugs from the leaking gaskets. Compression was nice and even in all cylinders. Well maintained these engines hold together for many, many miles or hours. I am planning on re-ringing the engine and tossing new bearings in it. If it weren't going in an Express van with the only way to remove the engine being removing the body I would probably leave it as is. I would not be putting the engine in if I weren't already in the process of rebuilding the suspension of a 1-ton Express chassis to slip under my 1/2 ton body.

Filthy junkyard pull on the outside





Pressure washed the outside before cracking it open.


What I found inside was actually quite nice. A little bit of carbonized oil but most of it wiped clean with a light touch. A little freshening up, a 425 HP mercruiser cam and she will be ready to move my Express pulling my travel trailer. I never have been afraid of beating up used stuff with minimal work though. The big chunks of carbon came off the intake from the EGR passageway.

69GTOby

I just picked up a pair of 906 vortec heads today. They came off a GM 350 truck replacement crate engine. The guy ran it for 15k miles and then decided to do a 5.3 swap. They appear to be in great shape.

I just need to decide now what I should use them on... I have a 1990 Cadillac Brougham with 74k miles. It runs great but has this detonation issue... The ECM detects spark knock when it's under load and retards the timing so much that you can feel a substantial power loss. I think the compression is just too high, especially with the tiny cam it probably has and the poor flowing heads and likely carbon build up further increasing compression. It definitely needs the valve seals which doesn't help anything.

Now the boat really needs some heads. The guides are so worn it won't idle right, smokes, etc... I'm just wary of bolting 40+ hp onto a stock and somewhat tired 28 year old bottom end. Hmmmmmm......

Damon

The Vortecs won't be a bolt-on for the Caddy. It was either a 305 or a 350 Chevy in that car and it used swirl-ports, different intake bolt pattern than the Vortecs. Vortecs (and their unique intake bolt pattern) weren't even available until 1996.

Should make your choice easier. And you DON'T HAVE TO USE that extra power all the time. I think they put throttles on boats, too. Pretty sure they do.

Plus, on a boat, if the motor stops running because it.... oh, I dunno.... INHALED A VALVE, it's a bit more serious than if your car stops running and you just pull to the side of the road.

69GTOby

Well, actually the boat is an '88 and the Caddy is a '90, and they both have the swirl port heads. So, they will both require a new intake, but that's not a big deal.

Regardless of where I use them, they are going to need some rocker arms. The seller did not bring them when we met up. I can get them from him, but I am wondering if I should go for some roller tip and maybe higher ratio pieces. Also, I remember reading the Vortec heads "require" "self aligning" rocker arms, or something to that affect. What is that all about? One more thing. Can I use some poly lock nuts on these rocker studs?

Damon

Vortecs use the same self-aligning rockers as your swirlies. Anything with centerbolt valve covers use the same rockers (although I've found a few 87s that still used standard non-self-aligning rocker arms).

Poly locks are for roller rockers. I wouldn't use them with factory pivot-ball rockers- not enough contact area where the base of the poly lock touches the rocker ball. I would just get a new set of stock rocker nuts. They are "pinched" at the top and old ones can sometimes lose their grip on the rocker stud and allow them to slowly back off in extended use.

69GTOby

So, the stock valvetrain with the pinched style rocker nuts is adjustable right?

Fast355

iTrader: (2)

In a 350 it should be. Have only seen the shouldered rocker studs in one GM Smallblock. A LT4 is non adjustable from the factory.

69GTOby

Okay that is good to know. I will probably use my old rockers then in these heads. Unless, is there any benefit to using 1.6 or 1.65 rockers? on the exhaust only? Or, is it not worth it?

Also, the guy gave my a cam too. It's a stock truck cam with "1264" stamped on it. I was not able to find too much info on this cam. It is a roller cam, so I could use it in my Caddy. My thinking is that it is probably better than my stock cam, but not by much. I think it has something like .42 lift whereas my stock cam, I am guessing, is probably something like .385/.395... And the duration is something like 190/205 with the 1264 versus 180/190... I am just guessing here. Maybe someone else will have a better idea... I think I'll measure the lobes to get a better idea of the lift to aid in identification.

Fast355

iTrader: (2)

155 cam
179/194 @ .050
.350/.385" lift
109 LSA
106 ICL

264 cam
191/196 @ .050
.414/.428" lift
111 LSA
106 ICL

I like the 14097395 cam myself in a 305
196/206 @ .050
.431/.451" lift
109 LSA
106 ICL

The Elgin 1136 is pretty nice too
210/215 @ .050
.462/.470" lift
110 LSA
106 ICL

69GTOby

I am leaning towards doing a cam swap in the Caddy and replacing the valve stem seals. Since the heads are in good shape apart from the seals, I think I'll keep them in service. Can someone tell me what the best seals are? Do I need the "umbrella" type and/or the "o ring" type seals...?

I found a 1997 LT1 cam for sale in my area. Is there any year that is preferable or are they all about the same? I don't think I'll use that 1264 cam. It's just a stock truck cam. It's probably a little better than what's in there now, but for 50 or 75 bucks I can get a good used LT1 cam...

Fast355

iTrader: (2)

As old as these LT1s are it is getting tough to find a good used cam though. You can get a new 395' marine billet roller cam for $170.

I am using one in my Express and it pulls strong from off-idle through 5,200 rpm. It has a noticeable rumble to it but still pretty smooth overall. I think you would love the torque curve in your Caddy with its tall axle gearing and stock torque converter. I find myself CONSTANTLY having to let off the throttle to keep from running other drivers on freeway entrance ramps and on hills.

http://www.jegs.com/i/Chevrolet-Perf...97395/10002/-1

69GTOby

That is a good idea... I will look into that cam. Maybe even a slightly used one on ebay or CL. Man, it has a lot of off the seat duration but not so much duration at .05... Interesting. Actually the Caddy has a 3.23 rear, which isn't too low numerically speaking, and I did install a slight stall converter - 1500 or 1800 if I remember correctly. Would this cam allow my TBI system to function properly. I am sure it would need a tune, but I wonder how it would run without one, and how it would idle. How much vacuum does it produce at idle?

Fast355

iTrader: (2)

The advertised duration is at the lash point which GM says is 0.000" where aftermarket cams are either measured at .004 or .006". I have the 395' cam specs on my laptop and the are in the 250/260 @ .006 range.

Even a stock engine would benifit from some tuning.

69GTOby

Oh wow, that's why the seat duration looked so long. I didn't know anyone measured seat duration at no lift lol. I would definitely go with that cam if it wasn't 170$. I just can't justify the added cost if I can find a good used LT1 cam for 50-75$...

Plus that 395 cam sounds good - too good haha. The sound seems indicative of lots of overlap, relative to the stock one, which means low vacuum and idle issues. I guess that could get tuned out, but that's a whole different can of worms. I would love to do some tuning. I would LOVE it. But, it seems extremely tedious just to get the necessary equipment, software, and some knowledge to begin with.

Fast355

iTrader: (2)

The notes I have from a thread I ran across long ago where someone had sent their 395' off to get measured on a cam doctor.

249/264 @ .006
196/206 @ .050
.431/.451
109 LSA
105.5 ICL

86LG4Bird

iTrader: (1)

69GTO, That 395 cam has VERY little overlap. Don't just look at the 109 LSA; with its tiny duration numbers, you'd be hard pressed to notice any change in vacuum and idle quality from your stock cam. Even without a tune, it would run just fine and definitely make more power across the board.

69GTOby

Fast355, those duration numbers look more like what I was expecting, which makes sense since they're the figures achieved with .006 lift which is where most cam companies make they're measurements.

86LG, I see what you mean now. I don't why why it sounds like there's audible overlap in the video. Anyway, I picked up a 395 cam for the Caddy. I am eager to put it in. I just need to know what valve stem seals to get. There are so many to choose from; different brands, types, guide and stem sizes... It is a bit overwhelming. The last thing I want is to do all this work and have an oil consumption issue.

jokerZ71

The 395 cam is a good mild cam.It has a flat torque curve (approx 400 ft/lb)that comes in just around 2000 rpm & holds out to 5000 on a 350.Even with it's 109 LSA, it has a good smooth idle & good vacum.It will run good w/o tuning, but, will really benefit from tuning.It responds really well with 1.6's on the intake.If no machining has been done to the guides, use PC valve seals for a 97 Chevy truck.
If you do use 1.6 rockers, you will wanna open up the pushrods holes in the heads to 1/2".You also need to measure the retainer to seal clearance. Personally, I would go ahead & use a set of LS valve springs with Comp 787 retainers. This will provide some added clearance & a more stable valve train.
You do need to be mindful of compression with this cam tho as it closes the intake very early & can easily create excessive cylinder psi.

Fast355

iTrader: (2)

The 395' cam has a noticeably chopier idle than a vortec cam. I have 1.7 rockers on mine with 2.02/1.60s in the heads, tri-y headers, high flow cats and it brings out the chopiness. If you look at the videos of the same cam in the mercruiser 350 mpi engine on youtube they have a fair bit of chop as well.

These heads need nothing to run the GM/Crane gold 1.6 rockers with the 395' cam. GM used box stock heads for the Ramjet crate engine. L31 350 + 395" cam + LT4 1.6 rockers + Ramjet intake + Headers = 350 hp

jokerZ71

With the exhaust lift at .480" with 1.6 rockers, it would be a good idea to check clearance'as i'm pretty sure GM did as well.
I've set up several sets of these heads & never found overall retainer to seal clearance to be less than .510", until recently, I came across a set of 906's that had .520" to .540" on all the intakes, but, some of the exhaust had as low as .475", which would just barely be safe for the stock cam.

jokerZ71

I have this cam now & the idle is smooth as butter at 650 rpm.We use quite a few of these in truck engines & i've yet to hear a choppy idle in a 350 with proper tuning.It can be slightly choppy
in a 305.Maybe your tune needs some work.I guess choppinesss can be very subjective tho.

Fast355

iTrader: (2)

Tune is great, no problem there. That is idling at the stock RPM. Even at 750 rpm it has more chop than a stock L31 cam. What you are failing to realize is just how much more aggressive those small cam lobes are with the 1.7:1 rockers. You are also overlooking the fact I have 2.02/1.60 valves and ported heads that flow alot better than stock. I am getting more flow through the valves in the overlap period than an otherwise stock L31 350 with 1.5:1 rockers would.

jokerZ71

The 1.7 rockers will have a slight effect at idle.Your porting & larger valves, would have very little to no effect at idle.I have duals into a single so mine would be less noticeable if it were there, but, there are 100's of videos if that cam idling on youtube.I don't hear what I would consider to be choppy in any i've looked at.Again, that's subjective.What I consider smooth may be choppy to you.

Fast355

iTrader: (2)

I have swapped numerous engines to ported/larger valve heads and not a single one of them sounded the same after. You can HEAR the effect of the overlap from the change from the first start up.

I put Dart iron Eagle 180s on a TBI engine with a baby LT4 cam years back. Very noticeable change in idle from the factory TBI heads/cam.

On a speed density EFI setup I have always had to tweak the VE tables from a rocker arm change. Sometimes as much as 6-10% in places. I have also had to make major adjustments for head work, even near idle. When you put vortec heads on a TBI engine, it runs so lean and retarded at idle it will not even idle without making the headers glow!

Fast355

iTrader: (2)

I have Tri-Ys into metallic core spun cats, into a dual in/single out bus muffler.

69GTOby

I installed a 395 cam in my Caddy. It definitely made some more power and of course, it doesn't smoke anymore after replacing the valve seals But, in an effort to get the most of my gains, I got a custom chip from Harris Performance. It runs a lot better with a lot of power, until after it warms up for a few minutes, then it starts detonating like crazy.

I put the timing a -6 base, and it didn't detonate but it felt really lazy. I put the timing at -4 base and it runs pretty well until it warms up. When it is warm I hear detonation at part throttle under load, and cruising in OD. At WOT when warm, it detonates something terrible all thru the power band. Driving normally, it does fine thru first and second, then in third I have to give it more gas to accelerate at a reasonable pace because it kind of falls on it face, and when I do so, it detonates. Then, it shifts into OD at about 45 and is very sensitive to throttle depression from 45 to 55 MPH. If I drive with any spirit at all it detonates. And if I go to pass someone, it sounds like a marching band!

Brian says every TBI head he has ever measured is about 75 cc. I have ready many times that TBI heads are ALL about 65 cc and the pistons are used to vary the CR. I guess I don't know what I have unless I take the heads off, but my guess is that this "custom" chip is more for trucks with dished pistons and lower CR than my car which probably has flat tops and closer to 9.5 or 9.7:1.

At this point I am pretty frustrated. I did all this work in vain it seems. I'll give it a tune up and fill up with 93 next time and see how she does. Any suggestions? Has anyone had this detonation problem?

Fast355

iTrader: (2)

From past experience I would not trust a thing he says. He probably messed the chip up more than he helped it. Reference Gearheac-efi.com and search his name for the truth. As for your detonation, have you checked the fuel pressure? I have seen a variety of issues with the fuel pump/fuel system and regulator in these cars and when they run lean they can detonate. Swirl ports are ALL 64-65cc, never seen a 76cc swirl port of any casting number. Trucks at 9.3/9.4:1 are not much lower in compression ratio unless they are 8600+ GVW and those are 8.75:1.

anesthes

iTrader: (12)

What model baja is it? I have a '91 baja I'm re-powering with a 305. Originally a 4.3 v6. It's a 174 sunsport.

-- Joe