Alright consider this first, this car is my daily driver and only vehicle right now. I need to do intake gaskets soon, due to the coolant leakage. So I figured I'd go ahead and clean the ports up with some 80 grit and do the ultimate tbi mods. But I also thought I'm halfway there to pulling the heads. If I pulled the heads, I'd install new valve springs and valve seals (lot of smoke on start up) and .015 steel shim head gasket. Thing is I only have about two days of down time at any given period and I'd really like to clean the heads up while I'm at it.

Should I go for doing it all in two days and not worry to much, espically if I don't clean the heads as much?
Try and buy another set of heads and intake for as cheap as possible so I could just swap them? If so how much would a tbi, intake, and heads be worth?
Just do the intake gaskets and be in and out in an afternoon?

 

Every time I've dived into a project under a time line, it took twice as much time as I had planned.

With that said, you don't have to pull the heads to do the valve seals. Just get an adapter that allows you to put air in through the spark plug hole to hold the valves open while you have the springs off. If you don't have an air compressor I've used rope to do the same thing, just put a bunch in through the spark plug hole and rotate the engine up towards the head. With that said, valve seals usually go because your valve guides are worn. A new set of seals will cover up the problem for 20 or 30 thousand miles untill your loose guides wear them out too. It's not a big deal, but something to know and understand.

If your not fluent in chip tuning, I would forgo the head swap untill later and just do the seals. Go find yourself a performer intake and do that while you have it apart. Should see a bit of a gain but not so much that chip tuning will be required.

 

the only upgrade id consider at this time would be to possibly swap the intake for a aftermarket one, and use a carb->TBI adapter.

you'll want a chip that will atleast delete the EGR(since the new intake wont have it, and you'll get an SES), and a better spark curve wouldnt hurt either.
otherwise, you should really leave it stock.


to "cleanup the ports" on the heads, they have to be pulled.
to do the valve seals, you dont need to pull the heads. either run compressed air into them, or do the rope trick.

 

Removing some rough edges and casting lines in the ports (in the manifold or heads) might reduce turbulance, but it's unlikely that you'll get much gain from this because the "pocket" areas of the heads are the limiting factors. If you take the heads off you'd be much better off smoothing and radiusing the short-side radius, blending the bowl and smoothing the valve guide boss ...just a few minutes work on each port can get you signifcant gains.

It shouldn't take more than a day to remove the heads, change the springs and seals and do a little pocket work. On the other hand, Murphy's Law applies very much to this sort of thing. You could run into trouble (read: delays) getting the exhaust manifolds off, etc...

 

Alright, I think I'm going to try and do it all at once even though murphy's law will get me. Where are some pictures of the port work that needs done (I know I saw it a long time ago)? Which valve springs should I go with considering a future lt1 cam swap? Advance sells a head gasket set that has everything but valve springs, but I think it will have a thick head gasket (.039?), should I get a thinner one?

 

.039" is a typical "rebuilder" head gasket. It'll drop compression vs. the stock head gasket that is thinner than that (don't know by how much but the factory head gasket on my 92 RS's 305 was definitely thinner than that).

Good luck with the porting. Remember that it's far easier to port an exhaust than an intake. If it looks like it will help on the exhaust side it probably will. An intake port, however, is more difficult to get good results for a novice.

If you change out the valve seals you have a golden opportunity to change the valve springs as well since you have to remove them just to get to the valve seals. Don't put in "stock" springs. Stock springs are barely adequate for a stock cam at 4500 RPMs. At least upgrade to something like a mild Comp 981 spring. A true drop-in replacement for stock with no machining required whatsoever, but much better suited to controlling the valves at higher RPMs and this includes even stock cams (little more pressure, little higher spring rate).

 

Like said, it'll take at least twice as long as you have.

The intake gasket is like a 2 hour job - BUT.... You need to get the intake off, clean off the old gasket material, and use the RTV on the china walls instead of the rubber gaskets ... however you need to let it dry for a couple hours BEFORE you reinstall the intake, then put on another bead of fresh RTV and lay on the intake, install bolts, torque to spec, and leave it alone overnight - that was the only way I ever got an intake to seal - every other method I tried I ended up with an oil leak.

You can get a Weiand 8000 intake if you want a better intake (adding a TBI adapter of course) - this intake has the EGR provision, although you'll need an EGR adapter as well - the EGR valve hits the valve covers or the TBI unit (can't remember which - it hits something). With this intake, you won't need any chip changes for now.

If it were me, I'd do the valve stem seals without removing the heads if I only had 2 days, and skip the rest, as the more you do, the more unforeseen trouble you'll find, the more need for chip tuning, and such. I know me - I'd end up spending enough on a taxi for the next 3 weeks to buy a vette!

 

Gladstoneiroc, you've got limited time, so concentrate your efforts where you'll get the biggest gain. The swirl port heads have bigger than normal intake runner volume and the exhaust ports flow abnormally well, so your time would really be best spent working in the pocket of the intake ports and then on the exhaust ports. Read the following link: Standard Abrasives - DIY Cylinder Head Porting Guide. Concentrate on Step 3: Short Side Radius and Bowl Work, and Step 4: The Exhaust Port

Also, see Porting Cylinder Heads by Engine Masters Magazine.

Keep in mind that you don't have much time, so concentrate on the short-side radius and bowl work - this is where your biggest gains will be (and also for the least work). Be aware that most of the gains from porting come from the few minutes of work done in each "pocket" ...and the swirl port heads have good flow through the runners and don't need much work there anyways. Be careful around the valve seats.

Look for springs with roughly 105-120 lbs seat pressure (@1.7") and 280-300 lbs open pressure (@~1.15-1.2"). Comp Cam's 981's seem to be well-liked (I have them myself).

If you get a thinner gasket you'll bump up your compression, maybe by a few points. That'll only be worth a few horsepower on a stockish L03. I wouldn't worry about it too much until you get your cam and start trying to squeeze every hp possible out of your engine.

Keep in mind that the more you alter the breathing characteristics of your engine the more tuning will be necessary.

Start early in the mornings so you'll have the most time possible. If things go smoothly you should get it done, but if Murphy's in a bad mood who knows what you'll run into.

 

I will add my 2 cents in on this. It may or may not put your job into perspective, but this is how mine typically end up. They take more time than they are supposed to and cost more money. This was my first TBI fiasco. Back when I owned my Chevrolet Astro, I was in the same position as you. I had owned the van for 50,000 miles, it had been relatively trouble free. It needed some work, but was a daily driver. I had a week vacation from work coming up. It needed intake gaskets bad and the engine had an exhaust valve that was not sealing well. I pulled the intake to find horrible, dirty looking intake ports. I pulled the heads to find that they needed a valve job (not unusal at 145,000 miles). Okay, no problem. Well when the heads went to the machine shop a crack was found. The shop took their sweet time. Unknown to me the shop substituted early CPI heads. I found out after I bolted on the heads and ended up having to get the CPI intake gaskets and modifying the intake to match the ports. No big deal with my dremel. Went to bolt on the exhaust manifolds and found a big crack in one. Couldn't find a cast iron one at a wrecking yard and didn't have $200.00 for a new one from the dealer. I picked up a pair of tubular manifolds from a similar year fullsize van 4.3. Bolted right up. Get everything back togather and the thing ran terrible under load. If you gave it more than 1/4 throttle it bogged BADLY. Starved for gas was my conclusion. Must be the heads and headers. Okay, toss in the 305 or 350 (don't honestly remember) injectors that were in my garage. Now I have grey smoke right after start-up until it goes into closed loop. OK, toss on VAFPR and build MAP adjuster, problem solved. It cost 3 times as much and took 2 weeks to make it driveable. I do have to admit that it had like 50 more horses after that though or atleast I felt that it did.

Now even my for fun jobs have issues.

 

Do any stock valve springs have more adquate pressure? If not I'll need to order them via summit or somewhere else. I was thinking fel pro 1094 steel shim head gasket, does that sound right? Then I will buy head bolts, intake gasket set, new exhaust gaskets (collector and header) and a tbi tuneup gasket set. I'm thinking of having the machine shop put the valve seals and springs in after I clean the heads up.
So now all I need to do is find a spare set of heads so that I'll be able to swap it all together in a weekend.
What else am I forgetting? I think I won't make too radical of changes that I can't run the stock ecm for a while longer. I have all the stuff except, I need to resoldier all my pins, but I think I'm just going to spring for ebl after this.

 

I ran a stock Van 350 TBI setup on my mild 305 build with nothing more than this little project.

The Jeep Barracks - Building an Adjustable MAP Sensor

PS-I didn't add the switch, just the actual circuit that I needed. I could adjust the MAP voltage and get a decent A/F mixture. I think I ended up with 4.5 volts KOEO with 350 injectors. Plenty of fuel @ WOT and not drowning @ idle with the cam.

Now that I am tuning, I would never look back. But it did get me from parked in the driveway blowing grey smoke to driving to work and back though.

 

Also keep in mind that it is VERY hard to do any kind of pocket work without nicking the valve seat and requiring a new valve job. I really, really think your overcomplicating things by pulling the heads off. It's like a 4 hour job to do the valve seals and you can replace the springs while you have them off. Taking the heads off is really a chore with the engine in the car. It's also very hard to clean the deck off sufficently without getting crud down in the cylinder bore.

 

like you said you are on a time line so just fix your problem the easiest way so you dont get stuck without a car the vacel seats and intake should be done i know its tempting but your going to rush your job and then could cause more damage than you started out with so you know what you can do i as well need to do a intake gasket so good luck and have fun lol

 

I always use a Dremel-type grinder when doing just a quick clean-up in the pockets. The Dremel's small and light enough to get around without nicking the seats and it can adequately smooth the short-side radius, bowl and valve guide boss. It takes a little longer with a Dremel, but it's really good for removing small amounts of metal with precision.

However, anytime you put a grinder into the pocket you run the risk of nicking a seat. I've got a steady hand and a good eye, so I always manage to get away with it. However, my father would destroy every seat in the head doing the same job ...so it's a risk and a judgement call on your behalf. If you're not going to tune the chip to take advantage of the improved airflow then it's probably not worth the risk ...unless you're confident that you can do it without nicking the seats and you're going to tune the chip in the future. If you're only going to smooth the short-side radius a little, then you might not need retuning because these heads had some variation from the factory and the generic PROM tune can deal with this. You could pick up a few horses or you could need a valve job. You might nick a seat or you might be steady enough to do a hundred pockets with a Dremel without nicking a seat - your call.

 

Ehhh, I'm impatient, I use a carbide cutter in an air grinder. I also have this obsession with smoothing the transition from the seat to the throat that usually bites me in the ***.

 

A year or two ago I got a set of 601s that already had a fresh 3-angle valve job. They were pretty clean, but I wanted to smooth out the pocket a little. At the same time a tech at my university machine shop "donated" a Dremel to my cause. The Dremel was so light and maneuverable that I decided to give it a try on a set of 624s that I had. It turned out really nicely - perfect for the short-side radius. It can't take off enough material to flatten out the radius, but it can smooth it really nicely and make a nice, big radius there. It's also really good for the valve guide boss - you can carve it down perfectly. But it does require lots of patience.

I can't imagine going anywhere near the seats with a die grinder without nicking them. I like to do the "big" stuff (ports, common wall, etc) with the die grinder and use the Dremel for the "detail" work (short-side radius, valve guide bosses, etc) afterwards. It works really well. I'm doing a set of 601s now. When I'm done, I'll try to get them flow benched and see what I get.

I also have some 187s that I'd like to port, if I get the time. I think it would be nice to finally get some numbers on a set of ported 187s. They seem really easy to port. The intake and exhaust runners are pretty big, so they don't seem to need much work in that regard. Plus, the swirl "ramp" covers much of the valve guide boss, so work there is reduced. The only things left are the short-side, bowl work and maybe the common wall (but the swirl ports have plenty of swirl anyway, so I'm not sure what needs to be done there).

I think it would be quite a kick in the *** if I can get them in the 240/180 range (with under-cut and back-cut valves and a valve job).

 

Okay, here's the plan. Borrow a set of l03 heads and intake and clean them up. Then wait til I have a compete day and then install.
I have access to a die grinder at work with a large compressor, but I'd like to buy a dremel to do most of the work at home. Does anyone have any recommendations are almost all electric dremels the same?

Here's the parts plan
Head gasket set 71.48
Head bolts 15.99
Fel Pro Steel Shim head gasket 40.00
TBI tuneup kit 26.99
Comp Cams 98116 69.99

Those prices are quoted from advance, where I work so I get an additional 20% off. Which would put me at 200 considering the need for little stuff. And if I do nick a valve seat, a valve job is only 150 more, which is quite a bit but that's what you get with a novice porter.
Then I'll buy the EBL, learn to tune over a couple months, and finally install a cam sometime next year/ xmas break. I'm not going to lie, this port work sounds exciting and to think all these mods after tune should result in better gas mileage.

 

The cheap knock-off Dremels will be just as good for what you're trying to do. These things take forever to remove large amounts of metal, but they're perfect for making a nice, smooth curve on the short-side radius and profiling the valve guide boss ...luckily that's the two areas that will give you the biggest gains when you port your heads.

If you have time, remove the major obstructions (casting ridges, etc) in the runners, do some smoothing and enlarging on the walls towards the outside of the cylinder as they meet the bowls (on the intakes anyways), blend the roof of the runner into the side walls, and profile the valve guide bosses a little with the die grinder. If you're confident that you've got a steady hand, smooth the transition from the throat into the bowl (opposite the short-side) and smooth the short-side radius with the die grinder -- BE CAREFUL near the seats! Then use the Dremel to further smooth and profile the short-side radius, smooth the transition from the seat to bowl and profile the valve guide boss. But keep in mind that the majority of your gains come from the short-side and valve guide boss work ...and you can do this with just a Dremel.

On the exhaust side, profile the short-side nice and "round" and make everything as smooth and polished as possible, and open up the size of the runners a bit ...and profile the valve guide boss good.

Properly done, porting and polishing can have a huge effect on torque and horsepower - don't underestimate it. You could pick up 20 horses with increases throughout the power band if you do it right. Also, better flowing heads pave the way for everything else to have more dramatic effects - your cam, headers, intake, etc will come alive because of increased headflow ...even a few cfm can make a big difference.

What I've described is much more than just the simple pocket porting that you could do in a day. Keep that in mind if you decide to have a go at it.