Thanks for the bump litespd. I know it’s been a while since I posted an update, but I haven’t been sitting on my hands. I’ve been meticulously drawing out the stock ’88 cradle electronically for reference as I plan my own cradle design, plus Christmas shopping, filling out cards, and attending parties have gotten in the way, and most recently we had a 3 day power outage and property damage from 140 km/h (~90 MPH) windstorm. Wild weather!

Anyways, I thought I’d take this chance to make a quick update on fuel injectors. Rather than replacing the OEM injectors with after market ones, I did some research and got some opinions here on PFF about cleaning them instead. There aren’t any shops in Canada that I could find that provide an uninstalled injector cleaning service, so I settled on sending them to an outfit in Oklahoma called Deatschwerks www.deatschwerks.com/catalog/injector_services.php Great company: fast turn around and a full report for $19 per injector. They disassemble, ultrasonically clean them, replace the internal filters, external o-rings, and test the coils, spray patterns, and compare flow rates. Not bad at all. Here’s my report card following cleaning. I can live with the 3.7% difference between the highest and lowest flowing injectors. Once I got them back, I masked the lower halves and painted them, of course, yellow!



Now back to the transmission-to-engine mounting fun. Anybody who’s swapped a Northstar already knows the basic issues with mating one up with a standard GM Metric bellhousing pattern, but for those who aren’t familiar, this post is for you. For starters, here’s the rear view of the N*:



I’ve labeled the six locations for bellhousing bolts to illustrate which ones need massaging for the F40 transmission. The problematic holes are B, E, and F. Unfortunately there’s not much that can be done about mounting hole B. It’s not drilled or tapped on the N* for good reason. There simply isn’t enough depth of material between the bellhousing flange surface and the side wall of cylinder #8. It may be possible to safely drill and tap the location up to 3/8 of an inch deep, but then it wouldn’t serve much purpose, and it would more likely distort the cylinder wall or pull the threads out if any amount of torque were applied. Hole E is simply an unthreaded hole with an alignment dowel pressed into it, so it can’t be used as is to secure the transmission. The hole is waaaay larger than the M12 bolts used to mate the transmission to the engine. Finally, the problem with hole F is that the hole in the transmission bellhousing doesn’t line up with hole in the engine block.

I started by addressing hole F. First, with the transmission mated to the engine, I drew out the dimensions of the two holes in relation to each other. This was an extra step I took so that anybody doing this in the future can design their own coupler with the key dimensions from the drawing. After some research, I decided to follow a similar (though not identical) design that PFF member “buds” used here, about 2/3 of the way down the first page www.fiero.nl/forum/Forum2/HTML/088691.html Note that regardless what design you use, there will be a need for some grinding on the engine flange since it covers a small arc of the actual bolt hole on the transmission.



With my drawing in hand, I transferred the dimensions of the larger area I wanted to grind off the engine flange onto the flange itself. This is the view looking rearwards. (I traced the cut-out electronically onto the photo because there were too many reflections to see them properly in the photo.)



Then I used my handy grinding burr to remove the excess material. It ground down surprisingly easily, though I had to stop a few times to clean the bit to keep it from galling.



And here’s the finished product, although I had to make a few minor adjustments later on, which I’ll describe later.



Next I needed to make my adapter. I started out by cutting a 1-3/16” length of 1” diameter steel rod. It goes amazingly fast with the right tools!


Then I fabricated the flat portion out of ¼” steel plate, drilled the 1” diameter arc using a hole saw, and finished by beveling the edges for good welding penetration. Here are the two pieces clamped in the vise ready to be fused into a single piece.



A quick zip-zap with the MIG welder on the inside and outside of the mating surfaces.



… and here’s the finished product once the welds were ground down smooth, and after a quick trip to the lathe to drill the 1/2" diameter hole through the center of the rod. The inside filet is the reason I needed to make a few adjustments to the engine flange notch. To make the adapter sit properly, I needed to grind a beveled edge on the flange.



The moment of truth actually took a few test fittings since I found I hadn’t ground away enough aluminum from the flange even after beveling it. No biggie. To install the adapter, I used an M12 X 1.75 X 70 (12.9) in the lower hole, and an M12 X 1.75 X 35 (12.9) in the upper hole.



Edited to change bolt lengths used.

[This message has been edited by Bloozberry (edited 02-21-2011).]

Blooze, this is probably one of very few detailed engine swaps here I've ever seen on PFF. I love the fact that you describe / mention / show what is going into the project. Plus the cleanness and show quality that is going into it. I'm not a fan of yellow paint, but that's your taste and preference. The top intake that is painted "fire red" is an awesome color; very hot.

Not just putting a engine and tranny together is the issue here, its all in the detail and recommended torque values indicated. Not many folks respect doing that when doing assembly. You know what I mean, not just torquing the heads down and the rest isn't important.

You do quality job and in the end it pays off, big time !! Plus you got on hell of a nice swap ! :P

Have a good X-mas...

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fierogt28

88 GT, Loaded, 5-speed.
88 GT, 5-speed. All original.

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