My bad - MFI issue

[eapcpa]

I just got a set of 69S Mag stacks to complete my intake system because I am running K&N filters and nobody told me that they will not fit 72 and later throttle bodies that had plastic stacks. I ASSUMED they would work. The stud spacing on the throttles are wider than the stacks. I have two sets of throttle bodies for plastic stacks but need one set for the mag stacks. Dumb, Dumb Dumb Dumb. This is the second bone headed thing I have done. The first was fitting a twin plug distributor with a standard left side air channel after I had the channel powdercoated. Now I have to modify the channel to clear the distributor and have it coated again.

[Grady Clay]

Ed,

I sympathize with your situation.

The beauty of these forums is you can search a wealth of information and if you don’t find a complete answer you can ask those questions. The only mistake you made was to not do Pelican homework.

The solution now is to post “WTB 2.0/2.2S throttle bodies” and “FS 2.4/2.7/3.0S/RS intake stacks and throttle bodies.”

Since you are fitting tin, you already have had your heads converted to twin plug. Something that could gone into that decision was the choice of 14 mm plugs or 12 mm plugs. There is an interference issue with 14 mm plugs that is solved with 12 mm plugs.

Sounds like a cool project in spite of a few setbacks. Good for you.

While you are searching, I’ll encourage you to find a steel air filter assembly including the pieces that go on top of the stacks. While the K&N flow better, you will want the OE parts eventually.

Best,
Grady

[eapcpa]

Thanks Grady,

I do have a complete 2.2S MFI engine in the car. It is a 1970S Targa and the engine is the original for the car. I rebuilt it 100,000 miles ago and it is very tired. My plan is to pull it and put it on the engine stand when the 2.7 goes in the car and maybe rebuild it again over time. If one day I sell the car, it (the 2.2) would go with the car and maybe the 2.7 but I would probably want to build a RS Replica for DE and fun and put the 2.7 in that. It is only time and money and we all have plenty of both. LOL!!

[Grady Clay]

Ed,

If eventually you want to have the 2.7 be correct as an RS, you will want to keep the 2.4 throttle bodies and plastic stacks. Most important will be a non-fire-damaged OE air filter assembly with all the stuff. Some of the unusual parts are the warm air intake, the ’73-only left heat exchanger, the left tin & alu tube between the two.

How far along is the assembly of the 2.7?

With all your extra time and money, collecting parts for the 2.2S rebuild could start.

Best,
Grady

[eapcpa]

The 2.7 is essentially a long block. I am test assembling everything and checking clearances since I am using 10.5:1 JE pistons, S cams, ARP studs and rod bolts, pistons have been coated on crowns and skirts by Swain Tech and machine work on case and heads by Ted Robinson. JB Racing did alignment sleeves on case at the through bolt holes and the 12 pin distributor. Ports have been massaged and smoothed and compression tested out at 10.3:1. Deck height (piston /head clearance) is 1mm and piston/valve clearance +1.5 mm intake and +2.0mm exhaust. Pulling heads for reassembly with final sealers and gaskets. I also designed and JB racing machined a set of 1" aluminum spacers to go under the K&N filters for the cold start injection hence the need for the mag stacks. I am running the spacers as a prototype on the 2.2 and it works well. I did not have the heart to drill the side of my S stacks for the cold start circuit just to run K&N filters. I will post pics when I get some time but I am a CPA I don't have much time until April 17th this year. Should be a pretty hot motor for an early lightweight.

[eapcpa]

Thanks to Grady, jbell959, and boboloo for setting me straight on the parts matching of throttle bodies and stacks. I had no idea the 69 stacks had 66mm stud spacing and starting in 70 they are wider. The 70 thru 73 stacks are interchangeable. So 69 is the oddball, funny how that works.