Blooze Own: An F355 Six Speed N* Build Thread (Page 75/126)
Sage JUL 23, 09:41 AM
Bloozberry JUL 23, 02:30 PM
I was very happy last night when I finally got the cradle installed all the way up into the frame of the car. It was a long journey to get to the same point I was at last month before I found out I had miscalculated the position of the engine on the cradle. I hummed and hawed at several different methods to fix the problem since none of them were going to be particularly easy to execute. I figured I had three options to shift the engine on the cradle 20 mm's to the left and 25 mm forward. I could either:

a. leave the cradle "as-is" and modify the brackets between the cradle and the engine/trans. (I opted out of this route for a number of reasons including the complexity of all three brackets, and the need to notch the front cradle cross member for the oil filter)

b. leave the brackets "as-is" and lengthen and relocate the engine/trans mounting bosses welded to the cradle. (Not a great option either since this would place greater bending loads on the longer bosses, and still require the need to notch the front cradle cross member for the oil filter). It would also have placed one of the bolts of the rubber engine mount directly in line with the wall of the tubing that makes up the front cradle cross member; or

c. leave the brackets "as-is" and relocate the entire front and rear cross members further forward on the cradle side rails, then shift the engine/trans mounting bosses (welded to the rear cross member) over to the left.

Option C is what I ended up doing even though it was fairly involved. I had to outright replace the old front and rear cradle cross members since once cut off, they were too short by two times the width of my cutting wheel. Then I had to set up a jig to re-weld the side rails and new fore and aft cross members back together. And finally I had to cut, bend, and weld new bosses on the aft cradle cross members since the old ones no longer fit properly, as well as drill new mounting holes in the new front cross member for the forward engine mount. In other words, I had to replace everything about the cradle except the two side rails. I'll update the cradle drawings I posted (several pages back) a little later this week to reflect the changes in case anyone uses my plans in the future.

Shifting the engine/trans forward on the cradle this way prevented me from having to notch the front cross member for the oil filter (or buying a remote filter system). However there was still the side-to-side issue where one of the (unused) mounting bosses cast on the transmission housing was going to interfere with the LH cradle side rail as mentioned several posts ago. Since it wasn't needed, I simply used a cut-off wheel on my angle grinder and sliced several sections off...



...until I got the clearance I was looking for:



With the cradle and transmission mods out of the way, I was ready to try stuffing it into the engine bay again (with fingers and toes crossed). Just getting the whole assembly onto wheel skates is an adventure in itself... I can't simply lower it onto the skates using the engine hoist because the legs of the hoist stand taller than the skates. With the crane, I've got to lower the whole assembly onto a set of blocks high enough to pull the crane legs out from under the cradle, then roll the skates under the cradle, then use a pair of low clearance floor jacks to raise the cradle off the blocks and finally lower it onto the skates. Whew! No wonder it takes so much time to get anything done!



This time everything slipped into place like it was coated in butter, but the engine bay could not have been made any smaller otherwise it would not have fit. There are four areas to keep an eye out for tight clearances. I'll showcase each trouble area with a photo and brief description starting with:

a. Aft valve cover and camshaft sensor to passenger main lower frame rail.

Here's a photo that shows the side clearance between the aft valve cover and the camshaft sensor to the lower passenger side main frame rail of the car... looking down from where the strut tower used to be:



There's only about 5 mm between the camshaft position sensor and the lower frame rail while the car is being lowered onto the cradle. The engine can't be shoved any further towards the driver's side because there is an equally small amount of clearance between the F40 transmission and the driver's side lower main frame rail. Once the sensor and valve cover passes the rail, there's more clearance since they sit well above the frame rail as shown here:



b. Aft valve cover to trunk wall.

The clearance between the aft valve cover and the trunk wall also changes as the cradle is installed. I first connected the two front cradle mounts to the car frame then pivoted the rear of the cradle up into position. I couldn't have done it this way without having trimmed the trunk wall as I did earlier on since the engine swings on a wide arc and would have interfered with the wall. Once fully installed, there's enough clearance between the valve cover and the trunk wall but not an overly large amount as seen here:



c. Transmission to driver's main lower frame rail.

As mentioned earlier, the F40 transmission comes within about 10 mm's of the driver's side main lower frame rail as the car is lowered onto the cradle. (One of the nice things about this design is that there are no need for lower frame rail notches.) The closest it comes is where the aft cast "fin" or gusset narrowly misses the rail where it tapers the most:



Any misalignment of the cradle to the car as the car is being lowered decreases that gap in a hurry and risks hanging up on the transmission or the valve cover.

Here's the side view showing what portions of the transmission are in line with the lower frame rail once the cradle is fully installed. (If you look carefully, you'll see a vertical silver line on the frame rail with a barely legible "C/L" scribbled beside it... that's where the transmission output shaft used to line up before moving the engine/trans forward 25 mm's. The wheel location hasn't changed so the axle will have to slant backwards from the transmission to the wheel to accommodate the change):



d. Forward valve cover and passenger deck lid hinge box.

In my particular project, there's bags of room between the forward valve cover and the cabin firewall given the 3" wheelbase stretch. Even more so since I've removed my deck lid hinge boxes for a different design.



This isn't the case with non-stretched cars though, so anyone considering my 25 mm raised cradle design on a non-stretched chassis should be aware that the passenger hinge box will almost certainly contact the top of the forward valve cover before the cradle is fully in place. One other thing to keep in mind as well is that I've removed my strut towers to accommodate my new rear suspension design, but they would have been in the way of the aft valve cover regardless.
cptsnoopy JUL 23, 07:48 PM
Awesome Dave!

The only concern I would have is how much strength are you giving up by cutting away the strut towers? I notched mine but filled it in with a 1/8" Steel plate to help reinforce the area to hopefully the original strength or better.

I really like how the engine looks in your engine bay, I cant wait to see the finished product.

Charlie
Bloozberry JUL 23, 09:49 PM
If I were to leave the gaping holes wide open where the strut towers once were, the frame strength would be somewhat compromised since there isn't much material triangulating the upper and lower frame rails anymore. I do plan to stiffen the area again using sheet metal to block off the holes and firm up the connection between the upper and lower rails, though the entire area will see a substantial reduction in vertical loads since the spring forces will be redirected fore and aft to a new structure just aft of the cabin.

I'll also have a third, mid-level frame rail installed running fore and aft between the cabin firewall and the strut tower cross brace (the one integral to the trunk wall) in order to mount the spring and push rod bell crank. This third rail should stiffen the rear frame in bending somewhat especially if I notch the upper frame rail to clear my tires at full jounce.
Will JUL 24, 08:07 AM
I know you said you were trying to keep the axles straight, but pretty much every other Northstar swap has kept the crankshaft centerline in the same place as stock...
Obviously that's easy with a 282 or other stock transmission... more difficult with the F40.
As you've noted, the clearances are extremely tight and the engine doesn't have to be very far out of position to screw things up. My "dance" to R&R my powertrain is amusing. I use an overhead chain hoist on an I-beam, and I have a three-point chain setup with the chains set to the right lengths to hold the powertrain level. From there it's up an inch, left an inch, up an inch, forward an inch, up an inch, right an inch, etc... just to keep the projections from the cradle from snagging fuel lines and A/C hoses and all the other things that are in my engine bay that aren't in yours right now. If GM had built Northstar Fieros, the cams to guide the motion of the powertrain assembly as it was installed in the body would be a sight to behold.

I don't know if I could have saved you a bunch of work if I'd watched this thread more closely or not.
Bloozberry JUL 26, 04:57 PM
Thanks for your insight Will. I laughed at the "dance" analogy.

This is just a quick post to advise anyone that's interested, that I've updated the basic cradle drawings on page 16, about halfway down the page, to reflect the new locations of the front and rear cradle cross members. I've also updated the drawings of the engine mount locations (and their effect on the engine and transmission locations) shown in the drawings on page 17, about 2/3rds of the way down.

(Edit: I should add that these changes don't affect any of the new rear suspension characteristics or dimensions posted earlier)

[This message has been edited by Bloozberry (edited 07-26-2013).]

Marvin McInnis JUL 26, 06:45 PM

quote
Originally posted by Will:

I can't get excited about CV joint angle with diff centerline +/- 1" from stock, and would barely even think about +/- 2".




When Porsche extended the wheelbase of all 911 models by 57 mm (2 1/4 in) in 1969, they left the engine and transmission where they were and simply moved the wheel hubs back and accepted the resulting axle misalignment angles. FWIW, this arrangement was trouble free over the 15 years and 125,000 miles I owned my '69 911S.

[This message has been edited by Marvin McInnis (edited 07-27-2013).]

Bloozberry JUL 26, 07:01 PM
Funny you should say. I spent an hour or so searching the internet yesterday for an image I saw a couple months ago depicting the top view of an AWD Porsche (couldn't remember what model) that had its fore and rear axles canted backwards by 15 or so degrees. Couldn't find the pic though. Regardless, I've read that most modern CV joints can handle up to 23 degrees so I wasn't especially worried about my configuration... although around here (where annual mechanical inspections are the norm) I try to avoid anything that might attract concern from the "know-it-all" mechanics.
Bloozberry JUL 30, 04:11 PM
I ordered the majority of the parts to build the rear suspension today. These are the parts I ordered from Summit Racing:

Shocks: QA1 Proma Star coil overs with 18 position external single adjustability P/N: HAL-DS501 qty 2
Rod ends (LH thread): QA1 3 piece PTFE lined 5/8"-18 male with 1/2" head bore, 31,390 lb load capacity, 10 deg misalign P/N: HML8-10T qty 10
Rod ends (RH thread): QA1 3 piece PTFE lined 5/8"-18 male with 1/2" head bore, 31,390 lb load capacity, 10 deg misalign P/N: HMR8-10T qty 10
Upper aft links: AFCO 5" X 5/8" swaged tube P/N 36175 qty 2
Upper fwd links: AFCO 7" X 5/8" swaged tube P/N 36177 qty 2
Lower links: AFCO 8" X 5/8" swaged tube P/N 36178 qty 4
Push rod links: AFCO 5" X 5/8" swaged tube P/N 36175 qty 2
Jam nuts RH thread (5 per package): QA1 5/8"-18 P/N JNR10S-1-5PK-QA1 qty 2
Jam nuts LH thread (5 per package): QA1 5/8"-18 P/N JNL10S-1-5PK-QA1 qty 2

And from Jegs:

Rod end spacers: 1/2" ID X 1/2" long P/N 555-64201 qty 20 (2 per package)

All of the rod ends and a couple of the swaged tubes were back-ordered so it may take a while for everything to get here. In the meantime, I've got to get cracking on removing the fiberglass body panels from my frame in order to properly prep the underlying metal and make some needed elbow room for the mods to the frame to accept the new suspension. More soon.

(edit: corrected wrong part numbers for rod ends and changed swaged tube lengths to accommodate jam nuts)

[This message has been edited by Bloozberry (edited 09-21-2013).]

Bloozberry AUG 05, 10:20 PM
Over the past couple days I've been chipping away at removing the F355 door panels and the rear quarters. The door skins had to come off because the IFG door panels are made with the rocker panels integrally moulded to the door bottoms, unlike the real F355. When the door is closed, it doesn't show that much to the untrained eye, but it looks very strange indeed when the door is opened since you expect to be greeted by a nice wide door sill, except there is none! That has to change for me to be happy, so off came the door panels. I don't know what the previous owner used to bond them onto the metal of the door, but it wasn't a walk in the park to get them off.

Next came the rear quarters including the rear valence panel and bumper cover. IFG moulded all of these parts together as one big piece so there aren't any parting lines where you'd expect to see them. There are many other problems with the original rear quarter panel including wheel arches that are too high, crooked belt lines, crooked rear bumper cover lines, and improperly formed door jambs to name a few. Luckily for myself and Yarmouth Fiero, 355Fiero out in Victoria BC already did much of this work on his panels, which he recently and very generously donated to help advance our projects. I also plan to replace the rear valence panel (the part with the tail lights) with a wire mesh version a-la F355 Challenge, install a new cross member under the rear window to tie in the new shocks, dog bones, and deck lid hinges, and finally install a rear bumper bar where there was none(!). Bottom line: the quarters had to come off.

The previous owner used fibreglass resin and Bondo to "glue" the door jamb portion of the rear quarters to the space frame. I was surprised at how tough that was to take apart. I ended up using a hammer and chisel to pry the area around the jambs away from the frame to break the bond. The only other place the rear quarters were held on was to the base of the sail panels. Again, the PO used Bondo to glue the sails to the quarters so separating them meant using a cut-off wheel on the angle grinder:



It was a bit tricky to get the cutting wheel to follow the joint, but overall it went pretty well. I wasn't too concerned about nicking my old quarters since I'll be replacing them with 355Fiero's quarters. (Regardless, all of these panels will only serve as bucks for new moulds that Yarmouth Fiero and I are planning). Once the base of the sail panels were sliced, the rear quarters simply slid off the rear of the frame with a little tugging and a little jiggling:



With that out of the way, I now have lots of room to start cleaning up the frame, building the mounts for the rear suspension, and planning the mid-mounted radiators:



Here's another view:



Edit: spelling)

[This message has been edited by Bloozberry (edited 08-06-2013).]