Printable Version of Topic

Posted by: sdoolin Feb 7 2025, 04:42 PM

Rebuilding(ish) my 2056. On my first build I was able to achieve a compression ratio of very nearly 9.0:1. With this build, I am having to add .020 spacers below the jugs to get any measurable deck height in the jugs. I am calculating a compression ratio of 8.6:1.

Will I notice the loss in compression ratio?

Posted by: technicalninja Feb 7 2025, 05:38 PM

You need AT LEAST .036 with cast and .040+ with forged pistons.

This is piston top to cylinder top (deck height).

I am assuming you are not using fire rings (shims on the head side of things).

Any less and you risk piston to head contact.

This is fatal!

The compression difference will be tiny.

Now, for proper quench action you want "as tight as possible without P-H contact".

The deck height MUST be measured in line with the pin.

The more piston to wall clearance you have the more deck clearance you need.

Run tight cast clearances and you can go tighter than .040.

Run loose forged clearance and you will need more.

Larger bores need more as well.

For performance engines I want to be ALWAYS less than .045...

Posted by: sdoolin Feb 7 2025, 06:02 PM

Measured deck height in the jug, with an .020 spacer below the jug, is just at .6mm. Add the 1mm in the HAM heads (do NOT start a separate conversation about this) and you get 1.6mm. Which is a lot. Without the .020 spacer the pistons rise above the top of the jugs. Which scares me.

No fire rings in the heads.

Posted by: Superhawk996 Feb 7 2025, 06:21 PM

Sounds like you are playing with fire.

Without seeing how you are measuring or the heads I wouldn’t start an engine with .6mm of deck height.

Posted by: technicalninja Feb 7 2025, 06:57 PM

Please post a picture of the combustion chamber of those HAM heads.

You're either running .024" deck height OR .064"

At .064" you are leaving 5-10% of the obtainable performance on the table AND the engine will be MORE prone to detonation.
You're building a turd.

At .024" it will most likely disintegrate directly after start up...

And if you are not open to the assistance of others regarding everything about this why in the world did you post at all?

If I had $$$ HAM heads and I was unsure of what I was doing I'd want as much feedback as possible.

Both me and the Hawk are serious engine builders, we both know what we are doing, sometimes we disagree but it is ALWAYS about minor things.

If you DON"T want help...

Posted by: sdoolin Feb 7 2025, 07:26 PM

Total deck height is 1.6mm. I am very sure of this.

Posted by: sdoolin Feb 7 2025, 07:27 PM

Yep, I don't want this help. Y'all go build your own shit.

Posted by: sdoolin Feb 7 2025, 07:29 PM

I especially like the turd bit.

Posted by: Superhawk996 Feb 7 2025, 07:30 PM

By definition, deck height has nothing to do with the head.

Posted by: sdoolin Feb 7 2025, 07:33 PM

Superhawk thank you for your reasonable response. I add the 1mm to overall deck height at the instruction of Len Hoffman at HAMM. I trust him. I really do.

Posted by: Superhawk996 Feb 7 2025, 07:44 PM

Len is an expert no doubt.

But, is it possible you misunderstood? What was his recommendation for deck height not including his head?

Unless you can guarantee the heads have been machined to have a slightly larger OD of the sealing surface than the OD of your cylinders you have a potential for contact between the piston and the head.

I don’t see how you can be running .6mm deck clearance and still only netting a 8.6:1 CR.

Proceed at your own risk. At a bare minimum I’d be triple checking the fit with Prussian Blue and then double checking the piston top with clay.

Tread carefully.

Posted by: Jack Standz Feb 8 2025, 03:05 AM

To answer your original question, probably not from just a small change in the CR.

That's with all things being equal. But, if your actual deck height is too large (and before it was "spot on"), and the quench is negatively affected, it will affect the motor's output.

Our 2056 has a CR about 8.5 or 8.6 (if I remember correctly, I have some notes somewhere). Nice motor & no complaints here. It turned out to be just what we wanted for a street motor in our '74.

LN Engineering heads are very very good. Would like a set or two for some upcoming projects. Their RS+ or LE200 heads are expensive too. When the motor is built according to Len's instructions, you will notice a huge difference in performance with these heads compared to standard heads or heads from mere mortals. Best wishes for the rebuild.

Posted by: sdoolin Feb 8 2025, 07:35 AM

Thank you sir, I appreciate this input. I am re-using a set of HAMM RS+ spec cylinder heads. They have about 4k miles on them and I agree with you about them. This motor ran very very nicely on its first build.

Posted by: sdoolin Feb 8 2025, 12:37 PM

Bolted things up on one side of the engine today and clayed the heads. I am measuring more than 0.1" between piston and valves. From my last build, this seems safe? I am double and triple checking as I have lost some trust in my own capabilities to do this stuff. Older than I used to be.

This is with a .020" spacer below the jugs. No "gaskets" in the heads.

Posted by: Superhawk996 Feb 8 2025, 01:43 PM

0.100” clearance to the exhaust valve is starting to push what I’d call reasonable for an aircooled street engine. There are water pumper race engines running less. The fact that you said “more than” rather than an exact number concerns me.

The clearance to intake isn’t as critical. The intake valve chases the piston on the intake stroke. The piston chases the exhaust valve on the exhaust stroke.

However, remember that air cooled engines run hot vs water-pumpers so growth of the exhaust valve, piston expansion, and rod stretch at high RPM and valve float at high RPM can be a thing.

I’d be checking that clay clearance on all 4 cylinders and making sure I’m making that measurement accurately and not just relying on 1 cylinder to represent all 4.

I’m also going to suggest that you should be talking with Len and following his advice for valve to piston clearances if you’re trying to build an engine that is trying to absolutely maximize HP by building to the edges of limits of safety that were built into stock components. Don’t rely exclusively on some internet dope like me.

Posted by: Jack Standz Feb 8 2025, 03:04 PM

A lot of this stuff requires carefully designing, measuring and implementing it into your engine build. We can't know what's up with your motor by typing on our keyboards. Heck, we don't know what cam you're running and whether it's lift exceeds coil bind in your heads. This is an important, but different issue than either piston to valve clearance or deck height.

We also don't know anything about your last build and how it went (or didn't).

Yes, double and triple check your measurements. Make sure you rotate the motor through at least 720 degrees (two+ full revolutions). It takes 2 revolutions of the crankshaft to complete one combustion cycle. Depending on your cam, you can have valves hit a piston at a point other than Top Dead Center(TDC). And, of course, clearance between the piston and valve is critical as well as deck height. One, so they don't hit each other. And, also so you have good quench and don't kill power.

If you don't trust your own capabilities, finding someone you do trust might be the best way forward. There are good competent engine builders out there. Something to consider.

Those heads cost more than $5,000 (with tax & shipping), it'd be a shame to not have them reach their full potential .

Posted by: sdoolin Feb 8 2025, 04:32 PM

Thank you both for the thoughtful replies. My original build is here - http://www.914world.com/bbs2/index.php?showtopic=273923.

The cam is a Webcam 9130. I set valve geometry on the first build and cut pushrods to length.

That build went very well, and the engine was very strong and reliable for just over 4k miles. It was a lot of fun. Due to my own mistakes after a rebuild to fix oil leaks, I find myself here. The only difference from this build to the original build is the crankshaft (and of course new bearings). Importantly in the first build I had to shave the tops of the jugs to achieve the compression I desired (9.0:1(ish)). Now I am having to use a .020" spacer under that same set of jugs to achieve close to my desired compression ratio.

I am trying to build this more on the reliable side than the hyper performance side to answer Hawk's question. And Hawk your not a dope.

I agree with measuring everything, repeatedly. So I took Hawk's advice and clayed all 4 cylinders. I am measuring 0.15", 0.15", 0.146", and 0.15" exhaust valve clearance across all 4 cylinders. Intake valve clearance is 0.14", 0.14", 0.102" and, 0.11". I'm going to try to get the intakes all closer to one another. I am comfortable with my deck height measurements (discussed previously).

Visually I am not seeing coil bind at the valve springs, but I haven't measured that yet. I was hoping to avoid that, but now feel obligated. I have done it before. But I really agree with the point about not leaving any performance on the table with respect to the cost of these heads. They are the single most expensive automotive parts I have ever purchased (except for the 3.8l pistons & cylinders for my 993). That is not a complaint towards HAMM.

Posted by: Superhawk996 Feb 8 2025, 10:28 PM

0.140” - 0.150” clearance to exhaust valves is a whole lot more comfortable. That “extra” 0.040” or 1 mm doesn’t seem like much but it’s a lot in engine build world and offsets a lot of thermal growth.

Keep measuring and mocking up as you go. It’s good standard practice to do several mockups before any final assembly. Better safe than sorry.

Posted by: sdoolin Feb 9 2025, 05:03 PM

Measured valve lift a bunch of times today. Worst case I am losing .036" of lift at the exhaust valves, and .018" of lift at the intake valves. Best case I am achieving slightly greater than advertised lift on this cam (.435). So I am good with it and am not going to bother measuring for new pushrods. The geometry at half lift looks really really good, things are lined up well.

Will proceed with final assembly.

I will have questions about oil pressure verification soon.

A pic, because pics help everything (and 914 world autorotates my pics for some reason)...

Posted by: sdoolin Feb 14 2025, 02:27 PM

I'll likely button this engine up this weekend, and I'm looking for suggestions on how to verify oil pressure, before I install it back into the chassis. I am considering:

1) Adding oil and turning the engine by hand (no spark plugs) until I see oil at the oil filter mounting point just upstream of the oil pump. This seems like it'd be difficult at best (turning against the friction of the rings and all of the valve train), and maybe even impossible to really generate any oil pressure.

2) bolting on the transmission and using the starter to turn the engine until I see oil at the oil filter mounting point.

I am very nervous about oil pressure as the only reason I'm doing this project is because I ran the engine (briefly) with low/no oil pressure and seized the rear most crank bearing. I never did determine with any confidence why there was low/no oil pressure. I suspect one or two things, but am mostly unsure.

All actionable suggestions appreciated.

Posted by: Jack Standz Feb 14 2025, 04:41 PM

Modified #2.

Bolt transmission to engine. Remove spark plugs. Make 1000% sure the fuel system and ignition system are disabled.

Hook up gauge to where the oil pressure sensor goes (use correct thread gauge). Here's one gauge kit:


https://www.harborfreight.com/engine-oil-pressure-test-kit-62621.html

Hopefully, you will have good oil pressure when you crank it.

Posted by: 930cabman Feb 14 2025, 04:52 PM

Have you checked crankshaft end play?

Posted by: worn Feb 14 2025, 07:12 PM

I am afraid that I have to agree. The help is valuable and the helpers are first rate. Still, simply discarding and disbelieving what you posted wasn’t fair nor was it helpful. I am only chiming in because not doing that is what makes this board great compared to some where a poster is assumed to be stupid until proven otherwise. All of the posters are people that I respect and admire.

To put my own neck on the block I would say that my experience with a 2056 has been to reduce compression. Too much heat. But I am the idiot who doesn’t torque head nuts

Posted by: sdoolin Feb 15 2025, 08:38 AM

Thanks for this, and the link. This will be my plan. Carbs won't be installed, no plugs. So no fuel and no spark. I'll order that gauge.

Cabman - I have checked end play, per the instructions in my 40 years old Haynes manual. Installed 2 shims, then flywheel, measured, subtracted .004 (or whatever the manual says), and then selected the third shim based on that measurement. I have not re-measured after third shim selection (flywheel not yet installed).

Posted by: sdoolin Feb 15 2025, 08:44 AM

Thank you worn. The first few responses to my original question were not helpful, and in fact I think the opposite. I try to post concise questions, based on things that I really need help with.

By and large, over the years, this forum and most of the members have been greatly helpful to me and most others.

This build will have slightly reduced compression over my first build. If I solve the oil pressure problem I'll be a happy camper.

Posted by: Al Meredith Feb 15 2025, 05:02 PM

Years ago when Len Hoffman was rebuilding heads he took a set of my 1.8 heads and welded up the stock 1.8 spark plug location and relocated it to the 2.0 location . Then he would tap the hole for a smaller motorcycle plug thus allowing more meat between the plug and the exhaust valve seat where the cracks form. The 1.8 has a combustion chamber of 52/53 CC and the 2.0 at 58/60 CC which calculates to 9.5 CR. KB 96MM pistons and a .040 squelch. The KB literature claims that the tight clearance makes the head run cooler. I'm running 44 MM carbs which tend to run rich therefor cooler. I have no cooling problems Al

Posted by: worn Feb 15 2025, 08:49 PM

What a story. Thanks. Adding this to a recent post in another thread from Clay I now know that 914s can run, and run quite well, with motorcycle parts sourced from Walmart.

Posted by: sdoolin Feb 16 2025, 04:08 PM

So I re-checked this today. Installed three shims (as measured for), rear main seal, and flywheel. Just trying to move the crank "for and aft" by hand, or even with an easy/gentle pry produces no discernable movement. Setting up a dial indicator to measure for and aft movement again yields no discernable movement. Spinning the crank with the dial indicator positioned as pictured below produces a maximum needle sweep in the dial of .1 mm (.0039"). Which might be right? I am not particularly comfortable with this measurement.

Posted by: Superhawk996 Feb 16 2025, 04:30 PM

No discernible crank end play is a no-go.

Redo until it is correct. Likely shims weren’t correctly measured / calculated. There is no harm in doing this several times to be sure it’s correct. When doing the mockup / measurement of shims the flywheel must be fully installed and torqued so that the flywheel s firmly seated to the crank. Personally I set and measure end play before installing the RMS since you need to remove / install flywheel several times to get the right shim selected and measured.

Disregard spinning the crank measurement that has no relevance to crank end play.

Hint #1: when you make this measurement the dial indicator must be perpendicular to the the flywheel. May just the the angle of the photo but to me it looks like it is at an angle.

Hint #2: mount your dial indicator to the engine. You want the relative measurement between the case and the flywheel only. Mounting the indicator to the engine stand adds error and uncertainty to what you are trying to measure . Alternatively you could have the magnetic base on the flywheel and the dial indicator touching off the case.

Posted by: sdoolin Feb 17 2025, 08:09 AM

Thank you Superhawk. I only installed the RMS as I had measured for the third shim and figured (wrongly) that I'd be good to go. I will re-measure all of this, and will attach the dial indicator to the flywheel as you suggest. I had not thought of that. I have a total of 6 shims, so hopefully some combination of them will work.

Posted by: stownsen914 Feb 17 2025, 08:15 AM

Separate from the crank end play, if you are asking if .004" of longitudinal runout measured as pictured at the perimeter of the flywheel is acceptable ... personally that amount would not concern me.

Posted by: sdoolin Feb 17 2025, 01:16 PM

Understood, thanks.

Posted by: sdoolin Feb 18 2025, 05:25 PM

I have measured all of the shims I have on hand (6 of them). They are - .0115, .0115, .012, .012, .014 & .015. My dial indicator and I had some long conversations today about positioning as I see fit, and I believe I came out on top. Will have the magnetic base on the flywheel, dial indicator tip on the case.

I'm gonna install the 2 thinnest shims I have, bolt up the flywheel and measure (again).

After the snowstorm comes and goes...

Posted by: sdoolin Feb 22 2025, 01:05 PM

So, I re-measured crank end play. Installed flywheel (no RMS) with two shims behind it. Measure end play with dial indicator on the flywheel tip of dial indicator on the case. I can't move the crank noticeably for and aft by hand. Prying very gently on the flywheel in the direction away from the cases I measure .43mm (.0169"). This is repeatable.

My manual says to subtract .004" from this, which yields .012". I have a shim of that thickness.

I'm not sure what value I am ultimately looking for after I install this third .012" shim?

Am I looking for .004" thrust with all three shims?

Posted by: Superhawk996 Feb 22 2025, 01:16 PM

Yes

Posted by: sdoolin Feb 22 2025, 02:04 PM

Thank you Superhawk. Installed third shim, remeasured. I am getting .14mm (.005") repeatedly. Based on my selection of shims, I am calling this good.

Now a strange question. Recall from a few posts back I am going to turn this engine over with the starter while it is on the bench. I'd like to confirm oil pressure. But, I'm not 100% certain how to do this?

Bolt up flywheel, bolt on transmission, install starter. Run the positive battery cable to the starter. Then? Do I need to ground the engine somehow? It will be sitting on an hydraulic lifting table that has a thick (1/2") sheet of delrin type material on it.

Posted by: Jack Standz Feb 22 2025, 02:24 PM

Add a cable from the negative side of the battery to the ground strap/bolt on the transmission.

Then attach a remote starter switch like this one, make your own, or use a heavy enough gauge wire to momentarily engage the starter.

https://www.amazon.com/INNOVA-3630-Remote-Starter-Switch/dp/B000EVU8MK/ref=mp_s_a_1_4?crid=2B6JU26578JSF&dib=eyJ2IjoiMSJ9. jn20zYKKsT5n6wN2EQ_O5t_zxkY4aKkAmh7v3agK2kmzhpVLtkmgfhvrc7cSqV5D24Vog1NKt0jrqHNL
SGtAwOI_5_f2LADXCyGJ6jE-ZvM3wq-N1Tuq2MQqBHFZsicEcogNw2vieyhDLumm-gQs78ah5ThB37BR_f_W1nzbT2zTYEccHmQm7oY-W3wbTM-ikUpJRz_KGJmczraRoNtcqw._Y5yR0vFPLJQ0YyO_N6o0V15w8n4XDvm0nxc6bHmhvs&dib_tag=se&keywords=remote+starter+switch&qid=1740255495&sprefix=remote+starter+switch%2Caps%2C176&sr=8-4

Posted by: Superhawk996 Feb 22 2025, 07:09 PM

Agree. That is in spec. Better a smidge loose than too tight. If I recall I think Raby may have posted somewhere he runs .006” on his high HP builds.

Posted by: Superhawk996 Feb 22 2025, 07:17 PM

I’m going to ask a question that I’ve assumed you already have done.

Did you use assembly lube on all bearings and cam / cam lobes / lifters as you did final assembly? You shouldn’t be spinning dry waiting on oil pressure from the pump. Apologize I didn’t bring this up earlier

2nd - have you primed the oil pump gears with a light coat of petroleum grease? This helps ensure a quick prime and build of oil pressure. Again sorry I’m asking late but this is easy to do still.

Posted by: sdoolin Feb 23 2025, 09:20 AM

Yep, all bearing inserts (cam & crank) coated with assembly lube (Red Line). Cam lobes coated with assembly lube, same with lifters. Rockers & pushrods & valve tops lightly primed with engine oil. Cylinders coated with engine oil. Oil pump gears coated with engine oil.

Update on oil pressure - spinning the engine by hand produced oil at the oil pump output. Bolted on oil filter mount, turning the engine by hand produces oil into the filter. Installing oil filter and oil cooler and more turning by hand and I am getting oil at the oil pressure sending unit bore. So I will forego mounting the transmission and starter to spin the engine, and will install into the chassis. I still plan to use my new oil pressure gauge on first cranking when the engine is in the car (no carbs no plugs).

Thanks everyone for all the help.

Posted by: Jack Standz Feb 23 2025, 02:51 PM

It's a good idea to fill the oil filter with oil before installing it.

Posted by: sdoolin Feb 27 2025, 10:37 AM

I have confused myself. It happens.

Having re-installed the distributor in roughly the same orientation as before this rebuild (the engine ran well), with the plug wires in the same orientation, I notice that the rotor is aligned with the wire that is for cylinder #2 when the engine is at known TDC for #1.

Rotor turns in a clockwise direction when engine is turned.

A pic...

Posted by: Superhawk996 Feb 27 2025, 12:15 PM

Follow the Haynes or factory manual to instill the dizzy drive and distributor

If what you have said is correct the dizzy drive is mis-installed. Each tooth is about 30 degrees of rotor rotation. Sounds like you are off by two or three teeth.

Posted by: sdoolin Feb 27 2025, 04:02 PM

Thank you superhawk. I'm a little embarrassed I didn't figure that out myself. Dizzy drive was mis-installed by a tooth or so. All good now.

Posted by: sdoolin Mar 2 2025, 05:23 PM

Engine went in on Friday. Easy peasy. After I poured a celebratory Bourbon, I realized I had installed the moustache bar incorrectly. Easy enough to fix. Attempted to start her up today. No go. Triple checked everything. No vacuum leaks. Fuel pump is working, carbs are getting gas, plenty of air, so it must be spark. Yep, dizzy driveshaft installed 180 degrees out.

My 40 years old Haynes manual (for a bus) says to install the dizzy driveshaft such that the "small" side of the slot is on the left hand side. Well, the left hand side, to me, is the drivers side of the engine. The Haynes manual should say to install the dizzy driveshaft such that the small side of the slot is on the left hand side of the engine when approaching the engine from the fan side. Anyway. I fixed that and she starts and runs. Not well. but the carbs need to be synched.

The worst bit is that my oil pressure light goes out for a short bit, then comes back on. It has done that about three times so I have shut it down and commenced heavy drinking.

I'll find a way to put a proper oil pressure gauge on it before I start it again. Sheesh. She is really putting up a fight.

Posted by: sdoolin Mar 3 2025, 10:30 AM

Could this be a faulty oil pressure sending switch? Green ight goes out (indicating good pressure), then comes back on after a few moments?

Posted by: VaccaRabite Mar 3 2025, 11:35 AM

Maybe. Or you are loosing pressure on warmup.
There is usually a spike of oil pressure on start up that fades as the oil comes to temp.
If you have an oil pressure gauge, what does it say?
Are you using a stock idiot light switch? Stock one is supposed to light up at 3-4 psi. But you can find plenty of switches that light up a lot higher then that. The dual pole switches light at close to 10 psi. Which STILL should not be an issue on a fresh engine.

Do the basic electric checks too. Make sure leads are tight and grounds are clean.

If this was first start, the light may have come on while it pumped oil to other systems, especially if you have an external oil cooler.

Zach

Posted by: Superhawk996 Mar 3 2025, 12:53 PM

If it were me I would not be starting the engine just relying on the idiot light.

Get a real gauge on it.

Posted by: sdoolin Mar 3 2025, 04:20 PM

Installed my brand new oil pressure test gauge (Harbor Freight) in the location of the OE pressure switch (which is remote from the normal case mounting location (you can see it in the pic a few posts back)). The line on the gauge is long enough that I can sit in the car and start/run it and see the gauge.

I am seeing 76 -78 psi of oil pressure at 2200 rpm. I'm not sure what is "normal", but for now I am going to call success and move on to fine tuning. I actually found a brand new OE oil pressure switch in one of my many boxes of spares, I'll install that. Previous owner installed an oil pressure gauge into the center console, but it has never worked so I imagine I'll finally fix that too. I will have questions because I'm no good with things that need wires to operate.

Let it run for about 5 mins. Oil pressure stayed at 70+ psi. The passenger side carb "leads" the drivers' side quite a bit, so I need to synch things up, and spend some time with a timing light to verify ignition timing.

I also noticed a small oil leak at the oil pressure relief valve, so I need to replace that crush washer.

Thanks everyone as always for the assistance. Should have her on the road again in a week's time. Then I have a 1990 Honda RC30 to restore...

Posted by: VaccaRabite Mar 4 2025, 06:20 AM

Your pressure is high because the oil is cold and you are likely using a 20w50 oil. It will drop into a normal range as it warms up.

"normal" will be 10psi for every 1000 rpm, or somewhere around there.

Having a real oil pressure gauge in the car is a good idea.

Zach

Posted by: rfinegan Mar 4 2025, 09:03 AM

Woohoo
glad you get the pressure...sounds like the wrong or bad sensor

Posted by: sdoolin Mar 4 2025, 09:10 AM

Yep, cold oil and running (expensive) Brad Penn 20W50. And yes, I think a bad oil pressure switch. I replaced it and all is good (green light goes out).

Posted by: sdoolin Mar 11 2025, 10:55 AM

She's alive, and running well(ish). Drove about 10 miles yesterday. Carbs are well synched, she idles well and takes throttle without drama. I think the timing is a little too advanced, I got a little spark knock on full throttle uphill climbing. I can fix that easy enough.

She doesn't feel quite as perky as she did before this build, but I haven't driven her in over a year, and I have new rings and bearings to break-in. I'm hoping after break-in she perks up a little more, hard for me to believe I can feel the difference between 9:1 and 8.8:1 compression ratio.

Found a pretty significant oil leak at both valve covers, which I hate. Just hate. I've ordered new bales and have fresh gaskets on-hand.

Thanks as always for all of the helpful responses to my questions. I'm sure I'll have more...

Posted by: friethmiller Mar 11 2025, 11:54 AM

@http://www.914world.com/bbs2/index.php?showuser=17299 ,

Congrats! Glad the build was successful. My build is coming soon. Still waiting on the machined/balanced parts.

Posted by: 930cabman Mar 11 2025, 12:17 PM

congrats, running/driving is great. I can't imagine a seat of the pants could "feel" a .2 change in compression. Having things broken in will help slightly.

Posted by: sdoolin Mar 11 2025, 02:56 PM

Moving on to some other fiddly projects. Oil pressure gauge in the cabin now functions (woulda been helpful 6 months ago). Oil temp gauge on this car has never worked. I discovered the fairly specific wire that connects the sending unit in the taco plate to the rest of the harness under the battery tray. Woulda been nice to know I had this before the engine went all back together, but I just found it in a box, inside of a box of spares that came with the car. That wire, which is very OE, will not connect to the sending unit. See pic below...



Seeing as I'm going to have to fabricate a wire anyway, what kind of connector attaches to that sending unit? Do I get a different sending unit?

I also found the cover plate for the taco plate that routes the wire up the front of the engine, so may employ that with my custom wire(ing).