Datsun Roadster Forum-311s.org

I was reading up on engine rebuilding since I am in the process. Stock 1600 5 main crank.

the question is: I have assembled the crank and mains and rear main seal. (soaked in oil and trimmed with a new razor.) The crank is very hard to turn. Like I use a ratchet to get leverage. It turns and isn't grindy just very tight. Is that normal or did I do something wrong already.

Does anybody have a checklist for building the motor. I looked all through the archives and couldn't find one. I have never built a motor but I can do it.

Any thoughts?

Thanks,

Cris

PlastiGauge it!

Well, the rope seals have a LOT of drag initially, but then get easy once the engine has run in. Spyder is right though, plastigauge is your friend...

Please explain plastigauge to a foreigner

Chris

OK...

I put the rings in dry. I soaked the main seal for 12hours and not 24. and the plastiguage says:

.051mm across all the mains.

I need to use a ratchet to turn it. I have lightly oiled the cylinder walls and that has taken up some of the drag.

If this is normal. Do I find TDC and install the head next or should I do the oil pan?

Thanks,

Cris

Did you lube up all the main bearings and rod bearings before installing.There is special start up lube for this.I have also heard that you should only rotate the crank shaft in the direction that it normally turns.
Arnold

I always used STP and straight 30 engine oil, 50/50 mix on all bearings and cylinder walls..Nice and sticky.
Crank without pistons and rods should be relativly free, but the new seal will have some drag. There are commercial assembly lubes, and a special one for the cam and lifters. An improperly lubed cam will be damaged in a less than a minute on startup without proper cam lube. Usualy the cam maker provides it, you can also buy it seperatly. CraneCams also mentions the cupped pushrod tips, at the top where the adjuster contacts it..I never thought of that, it's high load, and only splash lubed.
I'm doing an engine soon, glad you asked, now I know another place to pre lube.

Couple references
http://www.hotrod.com/techarticles/engi ... to_05.html
http://www.cranecams.com/index.php?show ... l=2&prt=15
http://mahleclevite.com/it_crankinstall.asp

The crank with no pistons/rods should be relatively easy to turn, almost by hand, especially with a soaked rope seal. Since you said you verified main bearing clearance, let me offer a couple of other things that should be checked.

Thrust clearance- this is the front to back movement of the crank
Crank out of round- did you have the crank measured for this
Block shift- main saddles no longer straight

If the issue popped up after installing the pistons/rods, then that would require looking in different areas. When exactly did the issue happen in the sequence of assembly?

Mark

Chris66 wrote:Please explain plastigauge to a foreigner

Chris

http://www.plastigaugeusa.com/how.html

Well I used assembly lube on everything. I didn't spin anything until I started putting pistons in. after the last piston I tried to turn it and I had to grab my ratchet to turn it. It can be done and there is no scoring. It just seems tight. But maybe that is the way it is.

Thrust clearance is a good question. I will check that.

Pushrod lube. Would have never thought of that one!

I did not lube the cam. Good thing I haven't installed it yet!

Seriously I am missing tons of stuff on this. I am going to wreck my engine... Is there a Tutorial on this that I missed. I have the service manual but it says assembly is the reverse of dis assembly...

As Always Thank You!

Cris

I think the dry pistons may be alot of the friction. It wouldn't take long to drop out the pistons and recheck.
Local ook store may have a good general "engine rebuilding for dummies" book. As far as the basics, a Pinto or a Bentley is the same.

I thought of some things to look at and a few common mistakes you probably didn't make...If you did, just don't admit it
1 Oil holes in bearings lined up with oil feed holes in rods, mains and cam bearings.
2. Pistons in the right holes, correct side forward.
3. IIRC, I think it's ALOT easier to get the valve lifters in place before the pistons are in.
4. Oil pump packed with light petrolium grease (old school was Vasoline)
5. all external oil gallery plugs back in the block
6. oil restrictor in place on the timing chain tensioner
7. thoroughly oil the front timing cover seal, dry seals tear up quickly
8. antidrainback tube in the oil filter, oil on the filter rubber seal
9. fill it with oil and prime the pump, counterclockwise rotation, until oil comes out rockers and timing chain tensioner. Sooner you fire it up after the priming the better, more oil in the passages. You can alwas re-prime it just before startup, then install the distributor tower and rest of distributor.
10. If you want to go synthetic motor oil, you MUST use conventional motor oil for startup and break in, first 2-4,000 miles or the rings won't seat. From many sources, Rotella T is the oil of choice forcam and bearing life. there are a couple posts on it here somewhere.

Ask questions..better than a pile of broken new parts.

I offer this as only advise. If you have never assembled a motor before, get someone to help you that has experience assembling engines. There are a lot of critical tolerances (and some not so) to ensure a successful rebuild. Your statement that,

crispy wrote:
Seriously I am missing tons of stuff on this. I am going to wreck my engine... Is there a Tutorial on this that I missed. I have the service manual but it says assembly is the reverse of dis assembly...

As Always Thank You!

Cris

should be a red flag to get some hands on help rather than us keyboard jockeys trying to help without actually being there to "feel" the issue. You have probably invested a lot of time and money so far. Don't risk it by not correctly assembling the engine, getting frustrated, and not completing the job and enjoying all your hard work and dollars.

Mark

dbrick wrote: 4. Oil pump packed with light petrolium grease (old school was Vasoline)

Excellent tip Dave. If the gears are dry, no amount of priming will get the oil flowing. (depending on the design, some will self-prime but why risk it?)

Mark

GeoffM wrote:

Chris66 wrote:Please explain plastigauge to a foreigner

Chris

http://www.plastigaugeusa.com/how.html

Thanks Geoff

crispy, take it all apart and start over, this time you turn the crank for each time you fasten a screw, follow Dave's posting.

Chris

Oil pump question.When I but together my U20 it was on an Engine stand.The pan and pump were installed with the engine upside down.This would mean there is no oil in the pump.Any suggestion of what I should do with out pulling the pan and pump to fill it with oil.
Thanks Arnold