Finishing a hot 1800 build

[Nut124]

Hello Phaetn, regarding your questions 1 and 2:

1. When you rebuild, you should check, verify and correct if needed any timing marks so that they are perfect when you are done. This is easily done during the dry build.

Check you adj cam pulleys for excess clearance. Mine would not run true and would cause a pulsating belt whine from alternating belt tension that was likely to result in premature belt failure. I had to use alu shim tape on the cam and thin plastic tape as shim between the pulley halves to keep it running concentric with the cam.

2. Timing cover: I cut mine in half just under the T-outlet hole. This way I can remove the top half and adjust cams w/o draining coolant. I used thin aluminum flat stock on the backside of the cover to build an interlocking design so the cover halves mate and stay aligned. I could take some pics.

[Nut124]

Here are some pics of the two piece belt cover. I used a Dremel thin circular cutting blade and cut at an angle.

The little screws I ordered online to be the exact length, used loctite and then flattened threaded ends with hammer on anvil. The aluminum on the back side is 1.5 x 1/16? with tapped screw holes.

[phaetn]

Well done!

I should have thought of that. My car never had a bolt in the middle hole (low and between the cam pulleys) and so I never thought of mounting it as two pieces. Silly me. Like you, I cut it to be able to access the cam pulleys without having to drain the coolant and remove the hose.

My '74 was the first year with the 1756cc (and last year of the small bumpers!) so it doesn't have a T junction like later Spiders do (many still with the 1800), it just has an S shaped upper rad hose right from the outlet affixed to the head (and the the thermostat is under that, too). The '74 is a great year but definitely has its idiosyncrasies.

Thanks for the tip re. the cam pulleys. They seem ok and aren't rubbing against the belt on either flange. Here's a pic from when I recently started disassembly:


Cheers,
phaetn

[jon8christine]

So AR never got back to me...typical for them...but Vicks said the problem with the aluminum 2L pulley is that the alternator belt groove doesn't line up with the stock 1800 alternator / water pump on the passenger side. If that's the case I don't understand how moving the alternator, but not the water pump pulley, alleviates that problem. Am I the only one who finds it weird that everyone has an aftermarket 2L aluminum pulley, but not one for the 1800? Oh well, at this point I'm sticking with the original iron one.

[RRoller123]

I have the aluminum crank pulley, on my 2L, the Alternator is on the driver's side, all fits perfectly. Only the 4 degree timing error was an issue. That was a lot more than just any small variation in how the block pointer is mounted or bent etc, (it isn't)

[jon8christine]

Hey Nut, when you installed your 8mm dome pistons and bigger valves did you have any clearance issues? The taller Vicks domes on pistons 1 and 4 are hitting on the head relief cuts, so I had to open them up a little.

https://drive.google.com/file/d/1-GDNfA ... p=drivesdk

https://drive.google.com/file/d/1-CEUTP ... p=drivesdk

I'm planning on putting play dough on top of the pistons and then dry building it, and then pulling the head to check valve clearance with the Vicks 40-80 cams that finally came in after 6 months.

[Nut124]

Yes, I do recall having had to dremel the head in those same spots.

I had no trouble with the valve reliefs although it was pretty close. Guy Croft says 0.080 axial and 0.040 radial is minimum. Cam has to be dialed in for this to be meaningful. You should be fine axially with the 40-80 cams, in the 0.120 range I think.

Is yours a 1800 or 2L? I used a 2L head in a 1800.

My bigger valves are just marginally bigger. I cut the seats as big as the insert would allow and then turned the valve OD down a bit to match the seat.

[jon8christine]

1800 block and head... Shimming the valves now before degreeing the cams

[Nut124]

1800 block and head... Shimming the valves now before degreeing the cams

With 1800 block, head and 8mm dome pistons, you might be pushing the limit on static CR, detonation.

Mine is 1800 block, 2l Head. My measurements indicated 10.5+ static CR. The 1800 head has some 5cc less volume vs 2L. This could put your CR in the 11.5+ range.

Did you have the head surfaced? Even 0.005" increases static CR.

Use premium fuel only and listen for signs of pinging, detonation.

[jon8christine]

I see your intake cam CL target was 107, and you ended up a little advanced from that. What was your exhaust cam CL target and where did you end up please?

[Nut124]

For the 40/80-80/40 cams, 108 would be a good C/L target for both IN and EX.

Even 104 would be better than 112.

I had mine set for 108-109 IN/EX.

[jon8christine]

Thanks. What spark plugs are you running in your "hot" setup? I was running NGK BPR6ES before and have some NGK Iridium IX BR9EIXs that I was going to run, but just curious?

[Nut124]

I was running NGK6 but it seemed too hot. Insulator was bright white even when running rich. Now running NGK7.

This was confirmed for me by a race engine builder I consult via Whatsapp.

NGK 9 would be for race.

[jon8christine]

Did you have to install a gear reduction starter after increasing compression?

My car always started decently easy (for an old carbureted car) when compression was low. But now with my rebuild the starter is having a hard time. I got it running long enough for the coolant to get hot and blow out my old deteriorated heater core gaskets and valve. Cleaned my new carpet and got it running again long enough to get the timing set, but it barely turns over. I took the battery to O'Reilly and they said it was good.
I'll probably put a known good battery in just to double check, but was wondering if the compression is just too high for the old girl and the gear reduction starter is generally needed?

[Nut124]

I doubt that the increased CR is what is the problem there. Most factory engines have more cranking compression with their lame cams even w flat pistons. A bigger cam lowers cranking compression, should make it easier to crank the engine.

When you assembled the block, did you do a turning torque test? Turn the short block around to assess turning torque?

The same with head on, fully assembled.

Either your starter motor is bad or something is wrong with the engine build.

Try taking out the plugs and then crank to see how it does.

Have you done a cranking compression test?

Ignition timing being off could make for hard cranking , starting.