1971 142 Turbo v2.0

Small update: liquid gasket did the trick on the adapter plate. The root cause is the thread minima for the fitting reduced the web to the screw hole and the gasket just didn't have enough area to seal. I'll want to fire up the leak checker cap again but idle is again improved and the car (for a first?) isn't missing below 1000RPM. Wanding an unlit MAPP gas torch around the engine bay has no effect on idle speed. The lower pipe with the IAC needs paint anyway and that should be the last investigation when that comes in and out.

In other milestones it drove on the freeway! Wastegate pressure (5-ish PSI) is pretty underwhelming but the noise is fantastic. Driving it in traffic is still as challenging as I remembered. The 6-puck clutch is quite chattery and starting on a hill is fraught. The 20yo brake pads are less than effective. All the rotors are cleared of rust and the pedal is firm but stopping is not brisk.

Edit: and it picked up the kid at school; that turned some heads amongst the collection of Toyota Siennas and Subarus.

Measured the driveshaft angles and not as bad as I thought it might be. I could definitely space the center bearing down a little and improve that joint to the rear of the engine, but, I may just move onto other puzzles for now. The car itself, on jack stands, is about 1.0 degrees nose up. Am I correct to think the front section is intended to be level by Volvo? The engine is already very close to the crossmember.

It's possible what I think is driveline vibration is (a) me not being used to it and (b) all new poly bushings in every location and Heim joints for the upper trailing arms and Panhard bar. I installed poly front bushings on the lower arms before the common consensus was lack of articulation was more harm than help.

New tires ready to bolt on: Falken Azenis RT615K+ in 215/45R-17. Looks nice and square on the 7.5" wheels.



As a road racer friend of mine said: "Those are some Falken good tires." How right he was. The car is transformed on the road.

I wonder if I've completely misunderstood my driveline angles. At the moment the differential pinion is almost parallel with the rear half of the driveshaft (pointing upwards) and, from what I read on the internet, that's probably wrong.

Should the differential angle be equal to the front driveshaft as per the picture below? Intuitively that makes sense (particularly when the axle travels upwards), but, as I'm delving into this for the first time - am I thinking about this right?



I have the Yoshifab adjustable upper links so I can readily change the angle. The car definitely vibrates at speed but there's so much NVH from everything else it's hard to nail down.

joel142 said:

I wonder if I've completely misunderstood my driveline angles. At the moment the differential pinion is almost parallel with the rear half of the driveshaft (pointing upwards) and, from what I read on the internet, that's probably wrong.

Should the differential angle be equal to the front driveshaft as per the picture below? Intuitively that makes sense (particularly when the axle travels upwards), but, as I'm delving into this for the first time - am I thinking about this right?

I have the Yoshifab adjustable upper links so I can readily change the angle. The car definitely vibrates at speed but there's so much NVH from everything else it's hard to nail down.

Click to expand...

Yes. That would be my first place to start with the rabbit hole of NVH. The pinion should be parallel with the rear of the front driveshaft, or the transmission (if using a 1 piece).

If its just barely off you can get some interesting on/off throttle noises that start leading you elsewhere. Had a guy last year bring me his car saying that his transmission needed rebuilt and the bearings were shot because of some funny noises when going off throttle. 1 turn on his upper links and the noise moved to loading, back off a half turn and it was quiet and vibration free.

More substantive updates later but the short of it:

• added a Innovate Motorsports SCG-1 boost controller and O2 wideband. Haven't done any logging yet but the rest of the features are spot on. I do miss my all VDO panel - this has more modern bling than I want and the oil temperature gauge got voted out.
• realigned drivetrain for the pinion to sit at same angle as front shaft. Much much less vibration.
• shockingly my oil thermostat and filter housing is leaking (just a slow drip from ORB seal. New one on the bench to try again. Haven't caved on the Improved Racing one yet.

Took it for a drive and am slowly working up the boost while eying the O2 although the SCG-1 will cut boost on A/F ratio as a failsafe too. I have that set to 12 right now and at 9PSI I'm still solidly 9.5-10.

New updates over the past month or so. Now that it's more like "maintenance phase" with a few new parts:

• Brake booster didn't survive the 10yrs in hibernation and (a) didn't boost the brakes and (b) set the on-brake idle to 2k. I would love to save some space in the engine compartment so I (briefly) went down the rabbit holes of swapping in a dual master and a balance bar or re-fabricating the booster stalk to accommodate a smaller diameter booster. Realizing that if I wanted to drive the car this summer I just needed a booster I bought a booster. This worked great but a couple of notes:
  • the master cylinder acorn nut extends about 0.020" too far out the front and seemed to be complete unadjustable inward - all the fasteners are line to line. There appears to be a lock nut behind the acorn (it was a different shade of metal) and it was up against the output pushrod. It also seemed like these are put on at ~90% yield. I opted to make an extra thick gasket to set the spacing. This may make this winter's Mustang GT cylinder swap a little more entertaining...
  • on the pushrod side that also seems to be a different length, but, it's not too critical. What's annoying is that shaft has no flats so I ended up grabbing the unthreaded portion with vice-grips. Workable but a bummer as it's so shiny and new.
• Air mass meter With the old AMM the mixture (according to the wideband) was ~12 at idle and I was getting an on-boost bog with the AFR's touching ~9.0. Since there wasn't even a part number printed on it I went ahead and got a new one. Installed that and sat down with my brickboard instructions and test lamp to adjust the AMM screw and...nothing happened; no matter the fussing. Tested the resistance and it's fixed at 280 ohms. The screw is just for show. Regardless, it was a huge improvement. At idle and cruise it's 14.5-15, under boost it's a solid 10.0 with no stumble and it pulls right to the red line.

The oil thermostat filter block also got replaced with another block that also leaks but slower. Now I'm thinking about how to use the original pancake thermostat, but, it still needs to fit in the available volume. Improved Racing may still get my money. At least for now the leak is a slow seep and it can be monitored and lived with.

Ejected the alternator mount on the highway and that turned off the water pump and that got things pretty hot. With much coasting and waiting for it to cool I got it home and then put it all back together. Inspecting things closely: no water in the oil, no oil in the water, good compression (150+/-3# across the board), coolant system held 15PSI for 30min. A great relief after seeing both gauges peg.



Whoops! What's that doing there? After ~600miles one of the screws holding the bracket to the block disappeared. Not quite sure why as looking at how the mount loads up the screw head it should all be in tension as belts are tightened. Regardless, put in a new screw and tightened it down. If it loosens up again it may require more thought. To whoever "engineered" this one the access with the oil filter, radiator hose, inlet pipe, exhaust manifold, and braided lines is completely obnoxious.

A while since both of those have been in the same frame.

Are you using Yoshifab aluminum alternator bushings by chance? I had similar issues when I used them but switched back to rubber bushings and all has been well.

oldschoolvolvo said:

Are you using Yoshifab aluminum alternator bushings by chance? I had similar issues when I used them but switched back to rubber bushings and all has been well.

Click to expand...

Mine is a completely custom bracket with no bushings at all: the alternator bolts into it and it's bolted onto the block. Maybe not the friendliest environment for the alternator but this setup isn't going to see a ton of miles. That's an interesting data point about other hard mount setups coming loose. There's a limit to how much you can triangulate as you can't put a bar through the alternator.

I should go and check through my goals on page 1 but, so far so good. Through the late summer and fall the car just worked: commuted, took the kid to soccer, was rowdy through the back roads, and pretty much did what I asked.

Just one update during that time - part throttle performance was a little lack luster and boost seemed to come on a little late. I gave the wastegate rod a couple of turns to preload the flapper and left the EBC to take care of any spiking. I immediately picked up boost about 500rpm sooner and dramatically improved the mid throttle. Make sense, I suppose, any gasses sneaking through the waste gate will just slow turbine response. Other than that it's fast and fun at 10PSI and while it could use an alignment it's a hoot and makes a phenomenal noise at full chat. In mid-september I handed over the keys to my road-racer friend for his opinion. He found it a little darty with a touch of bump steer but otherwise well behaved. We agreed that the 200 tread wear tires cover a lot of ills, the full poly and heim joint suspension doesn't hurt, and the tractor sourced shifter just made each shift an event.

Now that the dark and rain is here there is a smaller list of things to sort out:

• brakes Currently running rebuilt original calipers and disks. This survived the long break but now that the car is really working I can push them to fade pretty easily. I have a set of s60r front calipers and a rough plan of attack.
• engine angle As seen from above the engine is leaning back a few more degrees than optimal. Off throttle I still get a good amount of vibration that sounds like mid-car. The engine is the odd element out from the last driveline alignment.
• radiator ducting Need some. There are some old holes from old charge pipe routing to clean up and generally take care of closing off the front of the car.
• rear main seal Don't really want to do this, but, it appears to be the only leak on the car. For the moment it's a slow drip forming between the bell housing and the block. This would also give me a chance to make sure I'm not over compressing the clutch. I don't think I measured that in round 1.

First round of brake upgrade is to figure out the parking brake situation. Amazingly, the 330mm rear disks are the same ID and almost the right depth to fit the '71 after 35yrs. The Brembo drawings have almost enough detail to figure it all out but not quite enough to know precisely where the brake shoes land. The drawings do have enough dimensions to print a windowed version to check:



The pads come up almost to the inner lip with ~90% of the brake shoes contact the parking brake zone on the P2 rear rotors. There is a little bit of underhang but well behind the pivot point.



I really really want to keep the Canisto's but those, by repute, are pretty tough to get over the big brakes.

One more because 3D printing is awesome for this kind of stuff. One set of holes is 142 stock; second set P2 stock. As expected both fit but the P2 is a little looser (16.5 versus 16.25). I shouldn't be shocked Volvo is using the same brake shoe and centering hole diameter (while my wheels are lug centric...) after so many years when the font on the gauges is the same.

I'm continuing to work out the details on fitting P2 rear brakes under the Canistos. I directly measured (on P2 front rotors) that I need +14mm to clear the face of the front caliper. That may not be completely realistic to stay under the fenders and to keep a similar-to-stock scrub radius.

Leaving that aside, on the rear (according to to Brembo's measurements), I have 20mm from the wheel face to the outside disk face in the back and 18mm in the front. If the calipers are 12-ish mm narrower (a side) and are generally the same shape as the front then we're in business. If they're closer in size I think I still have some space between the fender lip and tire edge.

Can anyone give me the distance between the rear caliper split line and the front face?

That measurement seems unobtainable through googling.

Not much to report, re-insured the car at the end of August when I realized I was in danger of not driving it at all this summer. Otherwise, it's just been fine if I operate it between the lines. There are a few things on the punch list like "figure out why the battery goes flat in a week" have adequate work arounds so I end up ignoring them. For other things like "take off the transmission to figure out if the rear main seal failed or if that super slow drip comes from someplace else" I just can't muster up enthusiasm to make a running car not running.

Probably new brakes this winter as I scored a set of back brembo's off Craigslist a few months back so I have the complete collection. The solid rotors are turning a bit blue, but, to their credit the ceramic pads are hanging in there the occasional odd smells notwithstanding. I'm also thinking about ditching the 'K' cam (sweet move in 2006!) for something more turbo focused. The iPd cam seems like cheap thrills and I'm not on my backup M41 yet...

Was out and about in it today and it's not a 142 jaunt without something breaking:



Seattle's streets called: your spring rates and compression damping is too high! This is going to be such a pain. If I need to look at that every drive I'm going to go crazy. I've had the fuel gauge bezel off and it's amazingly annoying.

Non-update update: drove it around, took it to Costco, and aside from being a bit too low for practical it just did it's thing.

The boost controller is set to 10PSI which puts AFRs at 10.8 at the redline. Probably stop there as M41s aren't that thick on the ground and it's more than decently quick for a 51 year old car. Maybe this winter it gets the iPd turbo cam just to get a little more low end torque. If I'm getting into the gauges maybe get into the tach too and figure out why the needle bounces so much (probably just age and crude).

Couple notes:

• Updated to Bilsteins and this was a huge change from the KYB's. Previously the compression was so aggressive you could barely push on a corner down and I presumed that was the old school iPd lowering spring. The Bilsteins allows much more movement and are so much smoother over any kind of impact. The car is so much less jittery and poised.
• Solved tachometer bouncing. Based on some random googling added a ~2k resistor in between the coil and the instrument and that smoothed it right down. I think the arm might slew a little slower than before but I can shift at a consistent RPM now.
• Took the car out for a good run and then tucked it into the garage for the winter.

Sent the instrument cluster to Roger at RP-R Sports at the results are truly spectacular. By far the nicest part of the car now. Some illustrative before and afters below. Would highly highly recommend.

This thing is amazing