Sorting out issues with a new 1600

[Potato_Head]

Hello All,

I picked up a 66 roadster in April of this year and have been trying to get it running "perfectly". Any comments or suggestions are appreciated.

Issue #1 inconsistent fuel delivery.
replaced fuel pump - found that there was a few loose compression fittings in the new fuel line that the PO installed.
Pump would suck air but there were no fuel leaks.
There are some sections on the intake side that have rubber fuel line. Should I replace the rubber and have steel tubing all the way from the tank to
the fuel pump?

Issue #2 The distributor runs out of adjustment when trying to set the proper advance
Found that the mechanical advance plate was 180 out. Fixed that and then removed and replaced the distributor.
The timing marks are not steady when shining the timing light on them.
Seems like the rotor is still not pointed properly.
I think I will just go with an Electronic Distributor.

Issue #3 Compression
The engine was rebuilt approx 4,000 miles ago.
Flat top pistons are listed on the build sheet
Compression is 120# on all four cylinders
Is this too low? Especially for a new motor?

Issue #4 The engine is very difficult to turn over by hand.
There is a lot of resistance as the pistons approach TDC. I cannot use the belt to turn the motor and even using a wrench is very difficult.
The nut on the crank pulley is 1.5 inches. Seems larger than what is supposed to be there.
I do not remember this being the case with my previous 1600. Should there be a lot of resistance at TDC with the spark plugs removed?

Thank you!

[Bwk2000]

A couple points to help get you started:

Issue #1 Should make no difference to fuel delivery whether it’s rubber or steel lines. I would do a fuel flow test on the pump (even if it’s new) and a pressure test on the fuel system to see what’s up. If it turns out fine, then look for maybe a kink in the line, a restriction in the tank screen, carb screen or filter to explain the inconsistent fuel delivery issue.

Issue #2 “I think I will just go with an Electronic Distributor.” Good choice

Issue #3 120 is very low, even with flat tops. Is there a quick bleed down of pressure when you do the test or does it hold pressure? Also, did you ensure the butterfly valves were wide open during the compression test? If it still reads in the 120 range, borrow a different compression tester from a friend and try it again - Wouldn’t be the first time a gauge was wrong.

Issue #4 You should not be having that kind of difficulty turning the engine over after 4K miles. With the plugs out you should be able to turn it by hand with the belt. A little more resistance as each piston reaches TDC is expected due to valve spring compression, but not to the extent you are describing - Something is definitely amiss.

[Potato_Head]

Hello Bwk2000,

Thank you for taking the time to reply.

1) There was a slight kink in the rubber line at the tank. There is good flow now and the aftermarket fuel filter stays close to half full at idle and higher with higher revs.

2) Just sent in my order for the EI Distributor

3) I will do a leak down test this afternoon. I did hold the butterflys open. I will try another gauge. I think that I used this same one with a Kawasaki C10 and saw cylinder pressures of 195psi.

4) Agreed that something is odd. I guess I need to find a boroscope to look inside of the cylinders?

Michael

[Gregs672000]

Check valve lash... too tight can reduce compression numbers (I just found this on my U20 when two intake valves "self-adjusted" in opposite directions due to loose lock nuts, resulted in 10lbs difference... 225 in loose, 205 in too tight, high compression engine).
Strong battery and plugs out, throttle open for compression test. Leak down should give good info. At least they are equal! Agreed on trying another guage... one of mine is bad.
Is this a stock Cam? Valve springs are what typically cause resistance. Take a look and make sure they are not coil binding due to being incorrect, improper assembly/adjustment or a super high lift cam/no lash (all guesses). I can definitely feel the point where the springs are at max resistance in my own motor (high lift cam) and it would not be turntable by hand with anything but a good sized ratchet (plugs out).

[redroadster]

What's the story on the car been setting years ?
Possible the cam timing is off a tooth , but better see what the turning torque is 1st
It's not abnormal for a rebuilt eng. To be stiff to start to turn without compression but should ease after starting to turn

[Potato_Head]

Hello Kai, Greg and Redroadster,

Cold compression is 150, 150, 145, 150. I did a leak down test on #3 and found that air is getting past the exhaust valve. Readjusted all of the valves and installed the Ei distributor.

I think it is a stock cam. I didn't find anything in the paperwork to indicate otherwise. I have all of the receipts for the engine and transmission rebuilds. The valve springs do not seem to be binding, lots of room between the coils.

The engine is loose enough to turn with a crescent wrench until it gets to TDC on a cylinder. Then is takes two hands to bring it up and past. The crank nut is 1.25 inches. I'm looking for a socket that I could shave down to fit better with the ratchet.

The car was sitting for awhile after the rebuild. Not sure the exact amount of time. All of the hydraulics were rusty. Had brass inserts installed into the front calipers. Forgot to check the clutch secondary cylinder which bit me in the tail this weekend. It's the early style with the wider bolt pattern. The PO had modified the later version by grinding the mounting pads and slotting the holes.

Is there an easy way to check the Cam timing? I do have a rebuilt aluminum head. I may install it instead of redoing the valves in the iron head.

Thank you!

Michael

[redroadster]

The binding problem needs addressing ,,1st Im sure you know that . the #4 exhaust valve is closing and Intake opening when on TDC #1 of power stroke , evenly

[Gregs672000]

Good info. Same resistance with the plugs out I assume? Cam timing wouldn't likely make any difference here but there are known issues when unknowingly mixing/using metric and SAE timing gears on R16s (I'm not suggesting that this is related, just an FYI). 150lbs cold is still low but not horrible and is probably the result of flat tops vs stock domes in an R motor. The leak down result on #3 is disappointing on a rebuilt engine.

Options as I see it: I'm not at all familiar with push rod engines but I'm wondering if it is possible to isolate the resistance to the valve train by loosening or eliminating the actuation of the springs. Like I said, my engine will not move by hand without a ratchet on the crank with the springs approaching max compression. I don't know what else could cause resistance in only certain positions (vs say a tight rod bearing which I think would be constant). Was the engine bored oversize? Also, with the head off you can turn an R engine without issue right? Obviously if it still resists with the head off we have an issue ELSEWHERE!
Assuming the rings are seated and the engine has achieved it's highest compression, you will have to decide what impact running a lower compression motor will have on performance. Higher compression over stock does not increase performance THAT much unless the engine and fuel is equally as modified to take advantage. However, the performance loss from lower compression is less known to me, but I have seen tables that estimate power based on compression ratio so they may give a better idea, or other engine builders here may have more info. What I'm angling at here is Do you consider replacing the flat tops with stock domed pistons to get compression back to the 180-190 or so? With the head off you'll be 1/2 way there and assuming the bearings etc are all good you could potentially lightly hone the bores and replace the pistons and rings, oil pan, head and intake gaskets, then sell the flat tops as they will likely be U20 pistons (?). Or sell the motor as "rebuilt with a compression ratio for adding a turbo."

Sorry to you are here... hope it works out!

[Potato_Head]

Hello Greg,

I read through all of the receipts (lots) and it seems that Rallye didn't write part numbers on any of the order receipts. There were notes stating that the engine was a 3 main SAE 1600. I can only assume that Rallye would have supplied the correct SAE timing gear set.

The pistons are 40 over flat tops. No mention of them being for a 2000.

I read in the engine rebuilder notes that an aluminum head was supplied as a "parts donor". The exhaust valves were used in rebuilding the iron block. The rebuilder noted that the aluminum block's valves were longer (.006?) than the ones removed from the iron block. No mention of the final block size to indicate a reason to use flat tops.

I do have a complete 1500 engine. Might be time to read the stroker threads. Winter project along with the steering box and steering idler.

Thank you,
M

[Gregs672000]

As I recall you can use a U20 piston on an R engine but not the other way around without some minor mods to the R16 pistons (hits the crank counterbalance I think). I don't think they made a flat top specifically for an R motor, so I'm guessing it's technically "for" a U20. Again thinking of options, I hear that 3 main cranks/blocks are sought by folks who race 1600s. You may be able to negotiate a deal that gets you either the parts or the funds to go toward a stroker or that results in a comparably built street 1600. Again bummer about the exhaust valve leaking but it may not need more than a better valve (bent? Worn?) or cleaning up the seats a bit better. I defer to more knowledgeable folks about valve length etc.

[Gregs672000]

Hey Michael, out of curiosity I've been doing some quick Internet searching on engine power and compression. As we know 150 is lower than what we might expect from a newer R16, which I think is probably around 180-190. However there are a number of factors that contribute to the actual compression you see on the gauge, and 150 MAY not be that much of an issue. Does it have a stock Cam? As you probably know, a cam with more duration or lift may give different readings while cranking. Obviously, fairly equal numbers cylinder to cylinder is important, so fixing #3 exhaust is a no brainer though normally 5lbs can be due to a bit more oil on the cylinders as you progress through each one (better seal with each cranking of the motor). May be a bit late, but I do wonder what it has when warm.
Also, from my research and own experience, ignition timing is by far one of the most important factors in engine power, much more so than say air/fuel ratio. A stock distributor is not very adjustable beyond adding or subtracting timing everywhere throughout the curve, which is very imprecise and just as likely to hurt output at certain rpm than help it. A 123 distributor would give you the ability to adjust that timing ANYWHERE in the curve to suit what the engine wants and find "peak torque" at multiple rpms. This of course does require a dyno and time ($), and a somewhat expensive dizzy, but if you are thinking about spending money anyway this could give you some options as to WHERE to spend that treasure. Unfortunately just installing a 123 and guessing at what the engine wants isn't likely to produce best results, and on my engine (with high compression running on premium pump gas) a degree or two could result in knock and/or a loss in power... it does require a dyno and that's where I am in my own process... I need more dyno time to finalize the timing map after adding EFI etc.
Anyway, just some thoughts on a rainy day here in the Pacific Northwest...

[Gregs672000]

Hey Michael, out of curiosity I've been doing some quick Internet searching on engine power and compression. As we know 150 is lower than what we might expect from a newer R16, which I think is probably around 180-190. However there are a number of factors that contribute to the actual compression you see on the gauge, and 150 MAY not be that much of an issue. Does it have a stock Cam? As you probably know, a cam with more duration or lift may give different readings while cranking. Obviously, fairly equal numbers cylinder to cylinder is important, so fixing #3 exhaust is a no brainer though normally 5lbs can be due to a bit more oil on the cylinders as you progress through each one (better seal with each cranking of the motor). May be a bit late, but I do wonder what it has when warm.
Also, from my research and own experience, ignition timing is by far one of the most important factors in engine power, much more so than say air/fuel ratio. A stock distributor is not very adjustable beyond adding or subtracting timing everywhere throughout the curve, which is very imprecise and just as likely to hurt output at certain rpm than help it. A 123 distributor would give you the ability to adjust that timing ANYWHERE in the curve to suit what the engine wants and find "peak torque" at multiple rpms. This of course does require a dyno and time ($), and a somewhat expensive dizzy, but if you are thinking about spending money anyway this could give you some options as to WHERE to spend that treasure. Unfortunately just installing a 123 and guessing at what the engine wants isn't likely to produce best results, and on my engine (with high compression running on premium pump gas) a degree or two could result in knock and/or a loss in power... it does require a dyno and that's where I am in my own process... I need more dyno time to finalize the timing map after adding EFI etc.
Anyway, just some thoughts on a rainy day here in the Pacific Northwest...

[david premo]

Just curious, when you did your compression test did you prop up the two slides on the SU’s and hold the throttle wide open so the butterfly valves are fully open? Kinda important to get an accurate compression test.
Dave

[redroadster]

Really you just want to see what the 1st pump compression is, try it like 3 X , should be 65% of total compression 85 -90 lbs

[Potato_Head]

Hello Greg,

Isn't it all rain after Bumbershoot? It's been a long time since I lived in the PNW. Does Tacoma still have the aroma? I used to live near the Spanaway race track then moved North to Seattle then Everett. '89-91.

Regarding timing - I have the East Coast Datsun Electronic distributor. The module is supposed to have some extra functions but not sure how or if I should use them. I run 87 octane Ethanol Free gas with the timing set at the second to last mark. 14 degrees? No signs of pinging.

Currently in the car is a rebuilt 3 main SAE 1600. The block was rebuilt in the late 90s and it sat for 10-15 years then taken to a shop to be rebuilt again? The receipts are confusing. No part numbers on any of them!

I have a rebuilt 5 main 1600 with an aluminum Emissions head. It also has the .040 flat top pistons. I need to check the carbs to make sure they are for a 1600. They have 90 degree Red Fuel tubes which I think are for a 240Z. This engine is on a stand. It was rebuilt 30 years ago and never ran. I am thinking I should get it to someone that knows what they are doing to ensure the assembly has been done correctly. There is a possibility that it has a hot cam and H20 crank.

Then I also have a 65 1500 that is a basket case. The body has been stripped of the interior and wiring. Ready for scrapping or restoration. Not sure which yet. The 1500 has been fired up since i have owned it. Just sprayed fuel into the intake ports with the manifolds off. I won't do that again since I lost a lot of arm hair from the fire coming out of the exhaust ports.

I think I will have the aluminum head checked out and then install it onto the SAE 1600 and see what happens.

I wouldn't want to sell the SAE 1600 block as it is the original block for the car. If I decide to scrap the 1500 I will keep the engine and use the crank to make a stroker. This could change if the 5 main has the good stuff in it.

David and Redroadster,

I will redo the compression test with the slides held open and the engine warm to see if there is a difference. I will also try the 3x method. Ive always just done 10x.

Waiting on Fedex to deliver the slotted rotors and clutch cylinders tomorrow. It's still driving season here in the Atlanta area.

Michael