Magnum intake on LA engine??

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Superelbert

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OK guys, here is one for those with detail knowledge and experience...

I have a 318 with a DIY fuel injection system (Megasquirt) My current intake is a 2bbl 360 intake which i have modified with thrrottle body and injector bungs.

Looking at the "beer keg" style MPI manifold of the Magnum engines, this is a much better intake. Propper individual runners, good volume plenum, etc.. its all there.

Now, here's the questions..

First of all, does anybody know if the ports and water passages match up bwetween a magnum intake and an old LA style head?

And secondly;

The Magnum intake has holes for vertical attachment bolts. Does anybody have any idea if it is feasible to drill new angled holes suitable for the bolt pattern of the LA heads? Is there enough room??

I have a complete Magnum intake on hand for a good price, but that doesn't help if it just can't be made to work for me, so any input is much appreciated here!

Thanks! :glasses5:
 
i know you can put a LA intake on redrilled magnum heads. But afaik you cant put a magnum intake on LA's. The magnum also, i think has different sized ports.
 
The magnum intake is designed for low rpm torque and does not perform well at higher rpm's. One of the first mods folks do to magnum engines in trucks is to swap out the manifold for an M1.

You would be much better off with an aftermarket LA 4bbl intake.
 
Thank's for the input guys! O:)

Hmm.. if the ports don't match up, then the whole idea sort of falls flat on it's face..

The 360 intake I'm using now had larger ports than my 318 heads, but I solved this by radiusing the ports on my 318 in order to give a smooth transition.
But if the Magnum ports are alltogether different again... ??

With regards to RPM range, I'm not building a very radical engine, the plan is to put in a 410/425 lift mopar cam with 1.6 ratio roller rockers. What I'm aiming for is a good street engine with reasonable fuel economy and low end torque that will still pull a bit further and stronger than the stock engine.

My idea of using the mangnum intake was really inspired by the old Cross-ram intakes, where long runners were utilised in order to give a tuned "ram" effect.
In a way, the mangnum intake seems similar in that it allso has rather long separate runners, allthough folded up in a more compact way. (possible since there is no real fuel-distribution issues with MPI..

Or perhaps I'm just as well of using my current 360 Intake??
 
Well, making it work is a project probably not worth the effort since it would probably not pan out the way you would like. I would look to an updated intake.

A single plane with boss' for the dry F.I. system like your doing, MoPar has them for the Magnum heads. I'm not to sure if the older intakes would fit the plan. I'm sure it would be easy to drill and weld in bungs on an older intake even though the boss may not be there.

Or use Magnum heads on the LA block and proceed with the beer bbl. intake.
 
Just found a picture of a manifold with dual bolt pattern, i.e. both for magnum and LA. It is obvious that there is absolutely no room for re-drilling a Magnum intake to fit LA head bolt pattern, so there goes that one anyway..

Well, if I had a pair of Magnum heads, but then my newly acquired roller rocker set would be left redundant..


Naah.. guess I'll stick with my 360 Injection manifold yet...
 
Edelbrock sells an LA style FI manifold for Non-Magnums with fuel injection. It is part of their 360 fuel injection kit, but you can buy it seperately. You can also buy a Mopar M1 Magnum FI intake and redrill it for LA bolt pattern since it is a single plane and has plenty of room. You obviously figured out that you can't redrill a beer-barrel because of the lack of room.

3526.jpg


They also now have a new high-rpm Victor series of manifold in FI also, but its range is a race-only 5000-8000 rpm.
 
Thank's for the info and the pictures Flyboy! :)

Those manifods sure look tempting, but the price is probably less so.. I'm all in favour of buying second-hand or making do with what I have at hand, that's the way I try to make my hobby an affordable one.

The 360 manifold I modified for EFI was picked up for about 25$!

Uploaded soem pictures, one is of the 360 manifold cleaned and painted with injector bungs added and the intake milled up to accept the single bore TB.

The second is of the TB, a unit from a 3L 6-cylinder Opel Engine which I modified and adapted to suit the intake and a 6,2 chevy diesel air filter.

The last picture is from the engine bay with the air filter removed.

Looks a bit "home-grown" but it works and was done on the cheap!
 
Superelbert said:
Thank's for the info and the pictures Flyboy! :)

Those manifods sure look tempting, but the price is probably less so.. I'm all in favour of buying second-hand or making do with what I have at hand, that's the way I try to make my hobby an affordable one.

The 360 manifold I modified for EFI was picked up for about 25$!

Uploaded soem pictures, one is of the 360 manifold cleaned and painted with injector bungs added and the intake milled up to accept the single bore TB.

The second is of the TB, a unit from a 3L 6-cylinder Opel Engine which I modified and adapted to suit the intake and a 6,2 chevy diesel air filter.

The last picture is from the engine bay with the air filter removed.

Looks a bit "home-grown" but it works and was done on the cheap!
Click to expand...

I don't see any pictures?
 
Yes, you don't se any pictures!

Obviously, I goofed something up! :scratch:

Anyone know the secret behind the "attach files" function??
 
Ha ha ha ha, good one.

Good pictures, nice intake work.
 
Now that is as home-brew as you can get! That TB looks like a Propane injection unit.
 
hehe, yes, that's DIY EFI for you!

Did this when I was a student, no need to say I couldn't afford one of those fancy bolt-on set-up! Wel, couldn't aford it today either, hehe!

Anyway, it works great, That megasquirt controll box is fantastic stuff, guess I did the whole system for less than a new manifold and carb would have cost.

and being able to tweak the fuel (and ignition timing) for every load and RPM point on the fly whilst driving is very handy.


Still like the idea of a tuned ram intake system though.. perhaps I'll weld something up??
 
I ran across this 2 yr old thread after I started another with the same question a few months ago. My FABO searches always return hundreds of unrelated posts, so I miss a lot on the site.

Some people talk and talk. You do. Amazing job designing and fabricating your own MFI system. A store-bought one might look prettier, but they cost ~$4000 US and yours probably works better. Plus the pride. I love JY solutions.

I think a Magnum intake can be made to bolt to LA heads. I don't plan to drill my heads, I will just machine the intake a bit and bend curvy studs. For sure ports and water passages align because there are aftermarket intakes that can bolt to both LA or Magnum heads. There are slight variations in port widths, but ditto within the LA head family itself.

Be skeptical of the comments about Magnum heads being good only at low rpm. You mentioned Mopar's cross-ram intakes that tore up drag strips in the early '60's. Of course jumping off the line helps win a race, but everyone has also seen current muscle cars with long curved intake runners, and they aren't just for stump pulling. That some RAM truck owners switch to low single plane inlets and carbs proves nothing. When I was young, I had a Honda motorcycle w/ 4 separate exhaust pipes. There was a brisk after-market in "4 into 1" exhausts, claiming "25% more power". When Honda finally switched to factory 4 into 1 exhausts, the same companies seamlessly switched to marketing 4 separate exhausts claiming "25% more power". That only proves that tuners and their hard earned dollars are easily separated.
 
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