200 log intake

[FastRonald]

8) Has anyone ever cut off the log manifold and adapted something else? Has anyone ever just converted the entire thing to feul injection as the the e.f.i. set ups from Ford? The carb opening would simply be the air valve then.

 

[falcon fanatic]

modifications to the log are increasingly common and there are people here who can show you pictures of their work. I'm about to (about to...I've been saying that for six months ) cut the carb plate off of mine and mill and drill the log to mount a weber 38 right on it. I figure this mod alone must be worth a substantial power increase.

Your FI idea seems quite reasonable. All you need to do is drill and tap the runners as close to the ports as possible for injector bosses. Then you can porbably just pull the venturi out of your stock carb and use that as your throttle body. Add the appropriate sensors and you are probably good to go.

 

[CobraSix]

IMHO, the log head is a great candidate for an EFI set up. Modifications are more common now. I'm on my second modification now. Going from Offy to Aussie. Next...Forced Air... hehehe.

slade

 

[Anonymous]

I have used 1 1BBL and 1 2BBL with adapter to existing mount. 3 1BBLs using the Offy 3 iBBL manifold. I have also mounted 2, 4, and 6 1 BBL side draft carbs to the log. I also began one were I machined the log off and added bosses to the casting. Sold the latter to a friend that put it on a boat dont know if he ever finished it though. He passed away about 4 years ago.

 

[MustangSix]

A log engine with port EFI grafted on will run well, but may not make much more, if any, power than a carbed engine. Although fuel distribution and control will be vastly improved, the log will still flow only marginally better than before. The log is probably sized too small to really work well as an EFI plenum and the ports are too short to effectively improve cylinder filling.

One course of action would be to cut the log off completely. Pictured below is one I sliced up with a bandsaw. Then if you mill it flat, there is enough surface area to bolt a flange to the head. Then you can go wild with induction and exhaust.

 

[Anonymous]

Whoa! Are there two "Master of All Things Six" now? With identical thinking? Cool.


Seriously, do you still have that head? Ever consider selling it?

 

[66Sprint6]

Does mounting the carb, say the Holley 2300 that Im runnin, directly to the log make that big of a difference??? How much?
Matt

 

[addo]

Here, at least, there are still the old-timers and facilities to do this kind of stuff. But most people (customers) couldn't see any benefit. I could have one converted by next fortnight, and it would still flow inferior to an alloy head EFI unit. Which would cost 2/3 as much.

Cheers, Adam.

 

[FastRonald]

8) How did the work on the head go once you cut the log off go? Using my drill press I plan to drill ans tap holes to allow the exhaust and a tubing intake to be mounted.

 

[MustangSix]

The head is still on the shelf, as you see it. I got involved with other projects.

But this would be a good way to go, IMO. A tubing or composite intake would be easy enough and you could modify or build headers. By slicing off the head as shown you get rid of the 45degree bend that the exhaust has to take and you can port it more effectively.

 

[Guest]

The pic of the SawzAll under my name is there for a reason

Here's some shots of the exhaust porting before and after

I had many plans, but dropped them once the 250-2V head became more available. Intake design is an art form, who am I to do it? Then plan was to drill and tap the intake runners with a pipe tap, then screw in steel sleeves, port match, then weld a flange across all 6 sleeves then design an intake. I even bought a Crossflow EFI intake from Oz to work with for an EFI setup.

Personally, I think the best solution would be to modify the intake log for port injection, having the injectors in the top pointed as best as you could at the valve, then modify the intake opening for a GM-type dual-butterfly t-body like this

Then use either a MegaSquirt or SDSEFI fuel management system and drive it. There is only so much you can get from a log head, take it as such, IMO. BTW, welding to these heads isn't really recommended. Welding to cast takes special care and techniques. Add to that 30 years of heating and cooling the head each time the motor starts and it is too difficult to trust that the crystalline structure of the head could handle being welded.

Al

 

[Anonymous]

You can get a big horsepower boost by just "modifying" the log....No need to go crazy on it, and cut it into little tiny pieces....A couple of Al's pictures look like somthing out of the Texas sawzall massacre!

Later,

Doug

 

[Kinky6]

If you decide to go the slice and dice route on a stock head, Lynx in Australia still had a few of the intakes on the shelf to mount three SU or Weber side-draft carbs on a head like the Hackmeister shows. They still aren't making any more of the intakes for the 2V head that I want, though.

 

[Anonymous]

A log manifold dosent have to work all that poorly they can be designed to work quite well. In my 4 motorcycle carb engine I used the log as a manifold. In the 6 motorcycle carb version the log was more like a comunication port at high speed designed to need to pull some of its fuel charge from the log say 10%. 90% pulled straight from the carb. At low speed and cruse the comunication was greater. This arrangement allowed the use of smaller carbs for economy yet almost indivgual runner performance. It workerd well Unfortunatly the carbs that were aquired (for free) for it were the best size and the project got benched. I sold the head years later to a marine engine shop. He Past a few years back and I dont know what happend to it.

 

[xctasy]

I've been thinking a good deal about this lately, and have come to the conclusion that a log head partioned off to become an idependant runner amnifold, and three IDF 44's is just what a mean streeter 200 cuber needs.

Chokes (venturi size) need to be about 31 to 37 mm to flow well enough for performance. 33 mm chokes are ideal on the street.


Any ID Weber is massively expensive, but it would bolt on the the log okay.

I'm aware that side draft Webers like 45 DCOE's are harder to package. But with a total flow of 1050 cfm wide open throttle, they flow the same. Generally, idependent runners flow 175 to 185 cfm per barrel, and if you've got six of them, they don't over carb the engine.

I'm as certain as I can be that a vaccum tertairy set up with a 500 cfm #2300 carb sitting in the stock 1-bbl position, with vacuum operated 2-bbl 500's each side, would behave like a set of Webers at a fraction of the cost. These are 43mm carbs with 35 mm venturis. A stock 500 cfm carb is confortably good enough for well over 177 hp, but if its set up to only provide fuel to 3000 rpm, and then behave like like a trio of Webers past that point, they would be awesome. I'm thinking of doing it with my little log 200 engine.

Engines which beahve as independant runner (one venturi per cylinder) pulse tune like a sequential injection system, and can produce huge power with very small jets.

E.g. Hot Rod did a write up on a way overcarbed 350 with twin 650 Dominators, and it needed only eight 66 jets for an independant runner tunnel ram. 485 HP at 6200 RPM with what could be considered to be 1300 cfm from eight barrels. That's about 6.2 cc per second per hp. A 750 cfm vac sec carbs on a 351 reving to 5800 rpm, doing 375 hp, needs 6.6 cc per second to give 1 hp. So in terms of economy, the one venturi per cyl independant runner set ups can work better than a single discahrge set up.

 

[Anonymous]

XECUTE,


Try thinking motorcycle carbs and side draft configurations

 

[Guest]

Personally, I’d Forget IDF’s. I’ve got a buddy who has them on his built VW motor feeding 1bbl/cyl and they are a constant nightmare. He constantly has problems with them and usually has them apart at least twice a season, and the car only sees about 3000 miles per year of use. VWs don’t run all that well to begin with, regardless of induction method, but the carbs seem like real maintenance hounds.

This is the absolute way to go, TWM Induction gives you the look and operation of the Webers, but with the added benefit of EFI.

This would be an ultimate way to go. Imagine 6 air horns poking through the hood?

Al

 

[Anonymous]

And most have trouble affording 3 2bbls. Motorcycle carbs can be found for decent prices. Many are CV design they package tightly and after set require little mantaince. The price of EFI and the gear heads need to modify and actual EFI performance VS carb. EFI takes a back seat in my opinion unless turbocharged then EFI should be considered. To this date I havent seen much dino proof there is an advantage to paying somewere over 2500 dollars more for an EFI set up that most of the time delivers less HP than a carb.

 

[MustangSix]

I was looking at these for the crossflow. They are from an old Honda CBX, but Mikuni or Keihin flatslides would be cool.

 

[Anonymous]

Kool ! The problem I encountered was after a certian year a lot of the motorcycle carbs had no adjustments. Mikuni s would be great also the EdVac now owned by Edelbrock at the time appeared to be the ultimite.