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-   -   760 5 cylinder...scratching a 10 year itch (https://forums.turbobricks.com/showthread.php?t=341191)

James M 09-14-2020 12:28 AM

Congrats, I want videos indeed, you get that test drive in yet?

For videos I posted on YouTube, then used the embedded URL option and it worked well for me

escondidoron 09-14-2020 02:08 AM


Originally Posted by 940 16 valve (Post 6074622)
Transmission is now installed in the 760! As it sits now I have just over 3mm of extra depth that the slave can compress to allow for clutch wear. Does that sound reasonable to any who have experience with setting up a slave?

I just saw this tonight, so sorry about the late response. I've fabricated a similar concentric throwout bearing system for one of my non-Volvo cars, a 1962 Lotus Seven.

Your assumption regarding 3mm (1/8") pressure plate finger clearance to allow for clutch wear is likely a very good one.

I've adapted a Ford T-9 with close ratio gears and Quaife alloy housing to the original Lotus bellhousing. To get the shift lever in the proper location (and not shorten the trans input shaft) I needed to make a spacer / adapter to mate the T-9's bolt pattern to the bellhousing. I had also moved the engine aft a couple of inches as well which made the concentric throwout bearing an absolute necessity as there was no longer any room for an external lever to stick out of the bellhousing w/o hitting the chassis.


I had originally planned to use the Ford T/O assy used on all of the Zetec / Duratec 4-cylinder applications as they are incredibly inexpensive. However they are spring loaded to the tune of about 10lbs when compressed. I was concerned with the resulting thrust load on the crankshaft causing engine thrust bearing wear as they are not 360 degree bearings in my 1962 vintage engine. So I used a Tilton unit instead as they retract fully when no pedal pressure is applied. Much more expensive than the Ford unit but much cheaper than an engine bearing failure!

In order to set the depth of the throwout bearing assy I performed a simple experiment; I measured the pressure plate finger height with my brand new 0.250" thick clutch in place with a dial indicator. Then I repeated the measurement with a 0.188" thick used clutch in place. The pressure plate finger height difference was about 0.090". So I set my static clearance for the throwout bearing at 0.130" to allow ~50% margin. I also checked throwout bearing tracel at full clutch pedal travel and found that it was about 15mm. The Tilton concentric slave has 19mm (3/4") maximum travel. This is important as you don't want to be able to push the slave past it's maximum travel; It can come apart!

The Tilton concentric throwout bearing installed with the feed and bleed lines routed and secured. Note that the bleed line is the one at the top of the bearing assy and exits through the left most ho,le in the top of the bellhousing. This allows for easy and consistent bleed once everything is bolted up and in the car:

The Tilton bearing / slave assy has a very convenient mounting system. It screws to a large diameter tube that is concentric to the trans input shaft. I accommodated this tube in my transmission adapter design. A simple shoulder Allen head bolt screws into my adapter and serves as the anti-rotation stop. This allows you to set a very precise clearance adjustment at the time of installation w/o additional machining.

940 16 valve 09-16-2020 11:27 AM

Thanks for the confirmation escondidoron, that's comforting that you came up with a similar measurement for clutch wear. Appreciate you sharing it! Interesting what you mentioned about pushing the slave too far. I have 3/4" master which is what the mustang uses, but my clutch sure engages high, so that's on my mind. Maybe need to downsize the master.

Finally took it for a test drive last night! All seems well but I didn't go far or fast yet. Need to have an inspection done next. And need to wire the headlights, efan, and replace the broken e-brake cable the car came with (new one on the way from Volvo). I'll try and figure out a video at some point here.

Anybody have a S90 parts car? I also need to find a mounting solution for the ecu which is currently just sitting beside the clutch pedal. I noticed years ago when I saw a S90 at the yard last that they have a nice mount for the 4.4 ecu in that spot ...

escondidoron 09-16-2020 12:48 PM


Originally Posted by 940 16 valve (Post 6113825)
Appreciate you sharing it! Interesting what you mentioned about pushing the slave too far. I have 3/4" master which is what the Mustang uses, but my clutch sure engages high, so that's on my mind. Maybe need to downsize the master.

940, I'm pretty sure that you know this already, but you can put your mind at ease WRT slave cylinder over-travel with a simple calculation by comparing the volume of fluid displaced by the master cylinder at maximum stroke to the volume of fluid required for the slave cylinder to reach maximum travel. If your master cylinder's maximum fluid displacement is less than that required for the slave's max travel by some amount that will give you a safety factor you should be good to go. In my case Id decided that I wanted at least a 25% safety factor just to be on the absolutely safe side. The down side of this approach to sizing the components is that you will need to find the effective piston area for the Mustang slave cylinder and it's maximum travel.

When I was designing my application and planning to use the Ford 4-cyl slave I contacted the folks at Centric by telephone (310.218.1091) and explained what info I was looking for. Centric is a major aftermarket parts supplier. While most of their parts are produced overseas they have an engineering office in the Los Angeles area. I provided the engineer that I spoke with their p/n and the he was able to provide me with the max stroke and piston area as well as emailed me a drawing with all of the pertinent hole patterns.

Or, since the Mustang and your application both use a 3/4" master cylinder, another option is to compare the maximum stroke of your master cylinder to that of the Mustang. If yours is less than the Mustang you should be good to go.

In any case, if the max fluid displacement of your master cylinder is close to or greater than the max travel for your slave you should consider installing a travel stop on your clutch pedal or, as you have suggested, go to a smaller diameter master cylinder. An unintended upside of going to a smaller diameter master cylinder will be reduced pedal effort. But it will also require increased pedal travel to move the slave.

BTW I like what you're doing. Nice work.

940 16 valve 09-19-2020 12:18 AM

Another piece to look at. I may just put in a clutch stop for now, since the pedal effort seems fine.

Quick video to prove she runs. Inspection set for Monday so I can make the insurance company happy

940 16 valve 09-21-2020 05:11 PM

Over the weekend I got the headlights and e-fan wired, some wires tucked, and started re-wiring to the fuel pump relay can sit in the stock location. Inspection is happening later today.

I'm realizing I forget to stop an take progress photos very often.

Rolled the car back and swept under it for the first time in years...

Was wondering why I had trouble fitting the fan shroud that I had. Apparently the wider 92+ radiators are not as thick as the one on the 760V6. Cool!
Notice the gap in front, the shroud covers the entire top of the 92+ rad

Anybody have some euro corners that are in nice shape?

James M 09-21-2020 05:20 PM

How'd you go about the fuel pump relay, last I checked with you it was still a mystery, mines just keyed 12v but if you have it figured out let me know

GTJordan 09-22-2020 07:47 PM

Did they pass it?

940 16 valve 09-23-2020 03:01 PM

James - I did figure out the relay! I'll have to check cause I forget what pin it was, but there's a + trigger from M4.4 for the relay (unlink almost every other output which is a ground.

Also thanks for the hint on the tach. The M4.4 output does fire the tach, just shows me idling at about 300rpm. Does that seem consistent with that you have?

And yes, it passed! They let the one license plate light out that I missed slide. Registered it yesterday! Took it for a gas up and car wash and it really cleans up nicely. https://i.imgur.com/BiMKeQql.jpg It drives nicely overall.

I do have a loud rattle coming from the transmission at lower rpms in any gear if I give it more than about 25% throttle, which lasts about 5 seconds and then is quiet through the rest of the rev range. Not at all speed dependent. It's interesting cause it's reminiscent of what I would get at higher RPM's on the old 940 with b234 before I got my driveline angles sorted. Hopefully not just the harmonics of the whiteblock. Going to double check the driveshaft angles this weekend as a first step.

I had all the driveline angles bang on in the old car and had welded the trans mount at the right height for that setup. Maybe needs adjusted now that I've transplanted it. With the diff higher with IRS I had to shim the center carrier up all the way to get the drive angles reasonable. Probably pull the driveshaft this weekend (and drain the tranny fluid - ugh) and make sure it's right.

Other driving impressions, I like it so far with the rear springs and the koni's at +100% rebound - 3 clicks. The front is too bouncy, its an old set of IPD lowering springs with a coil cut. What can I expect. Hoping to use my spare strut housings to make some proper coilovers this winter. What would people suggest? If I have an effective spring rate of 200lb/in in the back, maybe 250 for the front? What length coils are people using without clearance issues?

Final thoughts - The front speakers keep cutting in and out. Too bad, I was hoping to keep the funky stock stereo with external equalizer for a while. Anybody aware of common issues with them? I'm guessing it's a bad transistor in the amp or something of the sort...
I have a slight rattle at idle which I think is the VVT hubs. Anybody have experience if they rattle when not hooked up? Probably time to talk to Aaron at Vast...

James M 09-24-2020 12:22 AM

Let me know on that relay whenever you find the time.

I get an accurate reading on my tac, 800 at warm idle. Not sure why yours would be different. Does it get more accurate when you rev it?

940 16 valve 09-24-2020 09:27 AM

Nah, it always reads low. Highway cruising is at something like 2000 RPM, so I guess the 6 cyl tach must be the issue. Thanks for confirming! I'll try and have a look today at the fuel pump relay today!

940 16 valve 09-25-2020 10:50 PM

For the fuel pump relay pins:
31b - to B27 from ecu
31 -ground
15 - switch 12V from the main relay
87 -to fuel pump

redblockpowered 09-26-2020 12:31 AM

170 lb/in front and rear wheel rates on my car still pretty much rides like stock, and seems a bit soft up front. 225 or 250 in the front would probably be my suggestion with 200 lb rears, with dampers/swaybars to match. I have a 740/940 suspension setup spreadsheet that I can clean up and post if you want. Might be useful although you'll probably need to weigh some (unsprung) stuff in the rear, and/or the whole car if you're feeling ambitious.

James M 09-26-2020 02:19 AM


Originally Posted by 940 16 valve (Post 6116381)
For the fuel pump relay pins:
31b - to B27 from ecu
31 -ground
15 - switch 12V from the main relay
87 -to fuel pump

Damn really? I could have sworn I was trying that but I may have been with a normal 4 pin relay, not the Volvo one.

Congrats on getting it inspected, wish CA would be as understanding as up there and let you put the motor in with COP.

940 16 valve 09-29-2020 11:28 AM


Originally Posted by redblockpowered (Post 6116401)
I have a 740/940 suspension setup spreadsheet that I can clean up and post if you want.

That would be great if you can! Anything that can help with making the right decision based on math and not guessing!

I know there's a weigh scale outside the city off the highway that I had used years ago. I'll see if it's still there.


Originally Posted by James M (Post 6116416)
Damn really? I could have sworn I was trying that but I may have been with a normal 4 pin relay, not the Volvo one.

Congrats on getting it inspected, wish CA would be as understanding as up there and let you put the motor in with COP.

Well it was just an insurance inspection so basically do the brakes, lights, and signals work. I guess for better and for worse things are pretty lax in Alberta otherwise though...

Came home Friday and there was an odd sound. Pulley came off the alternator, damn. I had just taken it into boost a bit for the first time a few minutes earlier. Looks like it spun enough to open the inner diameter of the pulley so it doesn't fit right now. New alt time. Hurty shoulder so my brother is going to help me swap it out next week.

Also got the base tune from VA5T loaded, so now I need to get it running so I can get him a log for tuning. Got my wideband installed so we can see about ditching the NBO2 and use the heater circuits for VVT control!

redblockpowered 09-30-2020 02:27 PM


This should work, you'll have to make a copy and put your own dimensions in especially for the IRS setup. I modified it from a Miata spreadsheet that I found, with dimensions I measured. Feel free to message me if you want to talk about this stuff/if anything seems confusing. For comparison's sake, here's a similar set of numbers for E46 M3s that I found, made by the same guy originally:


940 16 valve 10-12-2020 12:43 PM

My god! That's a huge spreadsheet. Certainly seems like the opposite of guessing which I like. I'll try and decode it when I get to doing the front coilovers, hopefully this winter.

Got the new alternator in so we're back in action! Also found a low miles crashed 99 S70 so I took the coils and harness which isn't falling apart. Also got the thermostat housing which has the 2 ports, but found out the 98- sensor is too long for the lower port. Not sure if I can get away with taking some material off the front....

Took the car for a longer trip yesterday. Having cold start challenges, and the fan seems to run all the time, so I'm going to test the coolant sensor today, guessing it's failed in the hot position.

Car has the expected T5 transmission rattle at ~2100-2400rpm, I'll try and fine tune the drive angles and see if I can make it any happier

940 16 valve 12-21-2020 11:22 PM

Well, 2 more months of daily driving the swap, and it's been a blast. Only hiccup was popping the intake hose off the throttle body when I got my updated tune with increased boost. It'll spin the tires in 1st and 2nd no problem now. Need an LSD!

As luck would have it a 1992 960 showed up at the yard. I'd been hoping to find one for a spare IRS subframe to mount my BMW LSD (a la Sander). Other cool thing is the driveshaft has a CV joint at the back which looks to be the same size as one of the medium case BMW diffs used. Very nice if the driveshaft and both halfshafts end up being bolt on.

This one just so happened to have 102k kms on the clock when crashed! I thought maybe the odometer had broken, but everything on it seemed in spectacular shape, so I grabbed the whole rear end. Also came with the rear sway for IRS which will be nice to have. And all the bushings on it (most of which are NLA) look good.

Also found a weight that bolts on the tailshaft of the T5 trans which seems to have reduced the rattle from ~2100-2300 partially.

Next up (hopefully over xmas) is to get the VVT working with motronic 4.4, and start getting things ready for some proper kaplhenke short coilovers up front.

(not loving what imgur has done with their site - anybody have other suggestions for image hosting?)

Anybody have any brilliant ideas for the tone ring for the speedo? I know I could do a signal converter (prefer not). I'm thinking if I could get someone to water jet a custom tone ring that looks like the BMW one, but with more teeth. Any other ideas?

You can click the right arrow to page through the images...

<blockquote class="imgur-embed-pub" lang="en" data-id="a/ZgJUpIe" data-context="false" ><a href="//imgur.com/a/ZgJUpIe"></a></blockquote><script async src="//s.imgur.com/min/embed.js" charset="utf-8"></script>

940 16 valve 12-29-2020 04:21 PM

Gotta love the holidays. A little bit of down time to make progress.

Donor car donated strut housing for modification. Got the IRS mostly apart, and I've started eyeballing how this BMW LSD is going to get welded in!

<blockquote class="imgur-embed-pub" lang="en" data-id="a/6YMbz50" data-context="false" ><a href="//imgur.com/a/6YMbz50"></a></blockquote><script async src="//s.imgur.com/min/embed.js" charset="utf-8"></script>

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