340 update

Just thought I'd bring you guys up to date on the future upgrade to my roadster. As of this point, I've got a NOS reman 340 short block on the engine stand in a plastic bag. It needs to be disassembled and cleaned up and be put back together with fresh rod bolts and maybe a few other things. It looks to have the stock .030 over high compression pistons. The bare 300 heads are in a box ready to send out for bigger valves and some light porting but I'm scouting around for a better set. The 2004r auto tranny is torn down on the bench, awaiting parts and modifications. But the big news today is the purchase of a blower. I found a deal on ebay on a blower from a Ford Lightning and bought it for about $215 plus shipping and didn't think that was a bad deal at all. The Lightning blower (M112) has an upward opening oblong inlet port which should be easily mated to a custom throttle body and inlet scoop, and should be better suited to the 340 than the M90 I have on the car now. This will allow me to develop a more refined blower installation, as well as assemble the complete power plant and transmission before doing the next swap. If I get energetic and finish up the mill I might even get the T-bird IRS done in time to swap it in at the same time but we'll just have to see on that one.

Anyway, that's where the upgrade is now. I'd like to be able to swap it in next winter, we'll see how it goes.

Jim

Wow, sounds like it'll be a monster. The m112 is the same supercharger that comes on the cobra stock, correct?

That should move the car along nicely! The M112 is designed for 5.0L engines and up, so it should be a good fit on a 340. Probably can even spin it a little slower, and still get good boost.

Bill

RobertEdgeworth Wrote:

Are you using iron or alloy heads?

Greg

Greg5599 Wrote:

Jim

I like your idea of half rounds. The trick is to figure out how big to make them and where to put them. If we only had a dyno and lots of time!!
When I was building my manifold, I thought about doing something similiar to the center ports. The concern I had with limiting air flow to the center cylinders, was I wasn't sure how much to limit it. Then factor in, that air distribution changes with air bypass valve position. So my thinking is what may work at WOT, may cause issues at part throttle cruise, or visa-versa.

In the end, I figured it would be best for me to make all the ports the same. Then add the air flow deflectors shown in the pic.
Then once I got it running, use the computer controlled fuel system to make sure each cylinder has the proper A/F ratio.

Cylinder distribution hasn't been a huge issue. It runs pretty good with a single table. However there are conditions where it runs better with a dual table. Such as free-rev, very low load conditions (bypass valve open). Also the dual table allows me to run slightly leaner mixtures.
The Mega-Squirt dual table does a good job of this, because if you have a certain cylinders that run lean only at certain throttle/MAP positions. You can adjust one of the VE tables for this area only, and leave the rest the same.
It is a little more difficult to tune a dual table, but not much.
What I do is tune it as best as possible under a single table. Then check the plugs, if some cylinders are richer then others. I wire the rich cylinders on one curcuit the leaner ones on the other. Then both VE tables start out with the same values, then are adjusted from there. It allows a great deal of flexability!

The ultimate set-up would be an EGT in each exhaust port and 8 VE tables. But that would be a little over-kill for the street!!

Bill

Bill,
Where did you find a FI ECU that will control the mixture in individual cylinders? Do you have an O2 sensor in each exhaust runner?



"In the end, I figured it would be best for me to make all the ports the same. Then add the air flow deflectors shown in the pic.
Then once I got it running, use the computer controlled fuel system to make sure each cylinder has the proper A/F ratio."

David

It won't control individual cylinders per-say. There are two outputs from the ECU. You can wire up to six injectors on a curcuit. So you could wire it 4/4, 5/3, or even 6/2.
I do not have individual O2 sensors. I have to do it the old fashion way, by reading the spark plugs, overall O2 reading, and using engine vacuum readings. It's a slower process, but does work.

Inovatemotorsports does make a 8 O2 set up. However its very expensive, and mostly used for dyno tuning race engines.

Bill

Jim,
I don't want to hijack your thread but I'd like to ask Bill in what RPM increments the injector rates can be changed. I did some quick reading on the Megasquirt and I can already see myself going down into another rabbit hole. Looks very appealing.

David

Hijack away David, I use the MS too and I don't mind at all.

It's very flexible. You can actually go into a file and set the increments you want so that for instance in the lower or midrance you have increments of 50 or 100 rpm but in the upper range you have increments of several hundred or a thousand or more. I think the current limitation is a 12x12 table so you have 12 increments for speed and 12 for manifold pressure. You can spread them out however you like.

I hadn't thought about the bypass valve. Because it is on the opposite end from the discharge port that should have a very significant effect on flow at high vacuum. It might even make sense to have an internal runner that directs the bypass air to the center of the intake. But I wonder if just as much air doesn't go through the blower under high vacuum conditions? Considering it is a positive displacement pump the discharge from it could even be flowing in reverse through the bypass port. It would depend on how much of a vacuum the blower is capable of producing.

All of this causes me to start reconsidering the air/air IC. But once you start down that road all sorts of odd configurations start coming to mind. How about an IR manifold plumbed to the IC? Maybe a dual log cross runner under the blower base? This could get real crazy.

Jim

David

As Jim mentioned, you can set the rpm bins where ever you like. I found it handy to be able to move them around as you get the tuning dailed in.

Jim
Interesting idea, under the right conditions it could be possible for air to enter through the bypass valve. Such as high vacuum low rpm.
One idea I have about an alternate route for the bypass air, would be to have a tube located directly and centered below the discharge port. Then curve it around up to the bypass inlet port.
It probably would need to be located outside the plenum, so it wouldn't disturb internial air flow. Once the bypass flow is re-routed, a I/R manifold could be more effective.
The draw back with this type of design would be, the overall height. To make it effective, I would think it would have to be fairly tall. In an installation such as yours, where hood clearance isn't an issue, it just may be worth the extra work!

Bill

I'm beginning to think so. Picture a low rise cross ram base running to dual logs. Above that a discharge plenum with a forward outlet plumbed to an a/a IC and then back to the dual logs. Careful plumbing would be needed to get even flow to both sides but it should otherwise be pretty effective. Something of a plumbing nightmare of course, but feasible, and it could be made considerably lower than my existing intake which would offset the extra deck height. The problem is with the configuration of the logs and interference with the injectors as ideally they would both occupy the same space. The blower will be here next week and I'll look to see how much room there is on each side between the housing and the rocker covers. I'm not a real fan of vertical injectors but if it leaves enough room inboard for the logs that could be a compromise I can accept. Otherwise they may have to go over the rocker covers, something I'm not in favor of at all, though it would be interesting to see how that effects the torque band. Where to put the IC is an entirely different question.

Jim

The Lightning blower came in yesterday. Not packed too well, it had grit in the rotors but once I blew it out it felt smooth enough. It doesn't really look that much bigger than the M90 I have on the car now, but has a much larger mounting flange. I dug out an old 340 intake earlier today to see how it'd fit. As the photo shows, there's just enough room for a set of vertically positioned injectors. Angled injectors would require a raised plenum such as is now on the car, and I'll probably do that, however I really want to maximize the intercooler area since it's much easier to plumb 3/4" coolant lines than 3" air hoses. Finding the room to route them is the problem of course and interference with the coolant lines is the issue. Though there may be room, it is much easier to package an air/liquid system. Once the heat sink is in place that is, and with a scratch-built intake manifold that is a matter of good planning. Supercharged boat intakes are a good example of well designed liquid intercoolers, but I'm not familiar with the 340 SBB ever being popular as a supercharged boat engine. Be nice if it had been but I couldn't be that lucky. So I can use them for inspiration, might even find a core in a usable size and configuration, but if I do it's likely to raise the blower even higher in the hood cutout and I'd really like not having to do any more trimming on the hood.

Anyway, about those injectors. Twenty years back when we were just starting to think that a custom injector intake might be a possibility, one of the big hold backs was that we were told by "reliable sources"? that the angle and placement of the injector, as well as the injector spray pattern were all very critical. And, as experience since then has shown us it was mostly poppycock. Yes, pointing the injector at the back of the valve should theoretically have some benefits but in actual practice you can't tell the difference. Probably. So far I have yet to see anybody prove it one way or the other. But the point is, injectors in ANY orientation are going to put fuel into the cylinder, and do it without puddling. That fuel is going to vaporize and burn. So the engine is going to run and be tunable, and those of us who grabbed the bull by the horns and built an injector intake never looked back, I dare you to find one of us who has. But an angled injector intake does look good, I'd be the first to admit it. Still, the second big reason I used the Rover placement for my 215 was so that I could use the late Rover fuel rail. That was a mistake. At that time I did not know how to properly build a custom fuel rail and it would take two attempts on an intake with staggered height injectors before I finally had it down. It's not a hard job. You do need the right supplies but they're readily available. A lathe helps but a skilled hand at the drill-press is all that is required.

I just stacked up a simulation of an inverted blower with a thick intercooler section and an open scoop. There are several interesting things about this stack. First, the blower housing can be dropped down as much as 3" making the overall height 1/2" less than the current intake. This will be offset by the additional height of the engine, about 1-1/4" so the as installed height would be 5/8" higher, no big deal. Second would be the use of vertical stacks at the heads, which we all know can be a very good thing. The injectors could be located at any point in those stacks, even concentric at the inlets and the top cover could be integrated into the inlet scoop. This construction is very feasible, but it doesn't match the cutout for my blower drive since the pulley is switched to the opposite side. That's not a huge problem, just one more complication and this may not be the best layout for me anyway.

Jim

Now there's one place that I really don't like the way this website's software works. If you type up a post and then try to attach a photo, if you have any issues with the upload it is very likely that you will lose everything that you've typed. I've had that happen several times now and it's a real pain trying to recreate an original composition. I don't think you can post it and then go back and edit the attachments either so that wouldn't be the solution.

Jim

Stinkin camera's not cooperating very well either so I don't have the shots I wanted for this. Anyway...

The first shot showed the Lightning M112 sitting on an old 340 intake with room for vertical injectors. Lots of other commentary in there that would have made interesting reading but it's gone. The second shot, which I'll load if I can shows the blower housing inverted, a pair of MGB heater cores sitting on top of it, and a couple of wood chunks to simulate the stack up of a second intake option, and the third shot shows space for air tube installation. The interesting commentary had to do with a concept intake system based on the second configuration. Measurements showed it to be shorter than my current intake by a half-inch or so with vertical stacks and a *big* intercooler core.

But, when you look at how much room there is to route the lines for an air/air intercooler you really have to ask if it is worth it. Probably the stacks and intercooler housing would stick through the hood, they would be several inches wider than the present blower and scoop.

But what about that air/air intercooler? It would not be all that hard to take discharge air from below the blower and route it forward. Then the issue becomes one of plumbing it to the intake ports evenly. This is something which is going to take some thought though since there are a lot of ways to accomplish that. Has anyone run across some definitive tests concerning intercooler induced lag?

Jim

Completing small manageable tasks regularly is what completion of these projects is all about. In my case it often means building or upgrading shop equipment to accomplish the needed task, but then I have the equipment for the next time. My Rover valve covers are an example. Bought cheap on ebay, they were pretty nasty and needed degreased and then bead blasted. This was the perfect excuse to finally finish the assembly of my parts washer sink which I'd been collecting parts for, for nearly two decades. At long last completed, filled with 15 gallons of mineral spirits and tested to find perfect operation, I was then able to degrease the valve covers, and now have a very good stainless parts washer sink with a cover and dual drainboards. Next step is bead blasting, but the HF bead blaster I got for xmas one year was in sorry shape. Leaky, cloudy window, bad lighting and clumpy beads, it was time to refit the thing. So apart it came and got reassembled this time in accordance with my own directions, with all seams sealed and caulked, clean glass, good lighting, and the beads sifted. I may even go so far as to build a cyclone to remove the dust. And then the valve covers get done. That just may be the trigger to disassemble the short block, check everything out and put it all back together, or more likely to order the parts for the transmission so I can put that back together.

And so the think moves on. In the meantime I've scrounged up some spare springs which I think I'll put in the car to lift it back up off the ground. Don't know how well I'll like that but it should be better than riding on the bump stops.

Jim