First timer:Rebuilding my own engine

[Ben's Z]

Long story short. I hauled my 83 turbo long block to Austin for a friend to rebuild in March. He has family problems so I am headed back to Austin on the 1st to pick it up. I am considering rebuilding the engine myself when I get it back. Naturally I will have the block, rods, pistons, crank, and head taken to a shop to be inspected. I have never rebuilt an engine myself before, but have watched it done in person and many Saturdays on Spike TV's powerblock. My question is this. How hard is it to do with the right tools, patience and time? Its not like I can't afford to have someone do it, but I feel this would be my next "step" in moving my skills forward and my ability to work on my own car. I think building an engine puts you in the top 20% of gearhead populace in ability. More of a "Right of Passage".

My thoughts were this.

Get it on the stand, and tear down. Mark all corresponding rods caps with their rods. Take the head off and take to machine shop in one piece. Allow them to convert from the present hydraulic set up to lash adjustment. (I have all the parts necessary to complete this).

Get the block back with all work done and freeze plugs installed. Paint block. Use FSM and other manuals to build short block. Install completed head from machine shop.

My questions come to checking wipe patterns on the cam. I have used 1982 Turbo cam in good shape, so barring any changes to the valvetrain geometry, i.e. decking the head and throwing off the chain tensioner enough to not adjust for timing, factory lash pads should work, correct?

This friend backing out on my really threw a wrench in to things. I was hoping to get this engine back and while I was waiting paint my engine bay, and install new AC lines and brake booster, etc, etc. Now I have to pull my old motor and trans, paint the engine bay and possibly rebuild the other engine myself. I wanted this done during the summer months because frankly this is our crappiest time of year to enjoy a classic here in southeast Texas IMHO.

I was quoted over the phone $1700 for a stock rebuild the other day after I got the news. While I'd rather not spend that much and learn to do it myself I don't know how much of a hassle I am in for. I hope with 165k on the engine it won't need to be overbored.

Thoughts and Suggestions?

[tlorber]

I'd say as long as you are mechanically inclined and have the interest and basic tools (including a torque wrench and ring compressor) you should go for it. With the motor clean, you can literally put the block in your living room and work on it as you have the time. That way this additional project will not add much time to the overall project.

The L series are about as simple as motors get so once the block and head work are done it is just a 3D puzzle with 100 or so pieces (I'd be curious to know the exact number).

By the way, last year I rebuilt my first transmission. I'd always been intimidated by the exploded diagrams but I figured at 46 years old it was time to "overcome my fear". The tranny has been working fine ever since.

Edited July 25, 2012 by tlorber

[Kurbycar32]

I vote for rebuilding yourself and many of the specialized tools like the ring compressor and cylinder hone are available for rent from most big chain auto parts stores. You need to own your own torque wrench and a micrometer would be nice. I have rebuilt 2 car motors and here are the tips i can give from an experienced amateur:

1. Reduce as many variables as possible. In this situation i would stick with your stock head and treat the conversion as a separate project to be performed on a known running motor. send the head in for a basic inspection/resurface

2. Buy a complete motor gasket kit. You will probably only use 2/3 of it but the kit will save you a ton of money in the long run and you will likely have gaskets you didnt even know you needed

3. Use new head bolts. The old ones are way too old to reuse

4. Put the nuts and bolts back where they came out. Otherwise you end up with a coffee can full of hardware you cant find homes for, or you put a short screw where a long should have gone and then the long screw ends up without a home. If you cant put the hardware back use zip lock baggies with labels

5. Buy nice bearings, you never want to replace them again

6. Use a tap and die set to chase the threads on any rough looking hardware, replace anything that looks too nasty

Hot Rod magazine had an article about blueprinting your own motor last month, you should probably pick up that issue and give it a read.http://www.hotrod.com/techarticles/engine/hrdp_1207_short_block_blueprinting_basics/

[Ben's Z]

Bagging and tagging parts and bolts is something I do pretty regularly anyhow. Regarding the head. The swap to a lash adjusted cam is not difficult at all. I would think the machine shop would be able to handle that.

Can wipe patters be checked by rotating the cam with the head off of the block or does it have to be done as a complete long block?

[zKars]

Remember that most of what the rebuilder charges for is work you CANNOT do at home. High precision measuring to determine what NEEDS to be done, then if needed, boring, sizing, straightening, etc. Yes you can re-assemble it instead of the shop to save money, but that's not much % of the total cost.

You cannot not just replace rings and bearings with stock sizes, run a hone in it, and clean things up to re-assemble and cross your fingers. Waste of time and energy. The engine is in better shape than that right now probably. You MUST pay the shop to at least evaluate things and let you know what NEEDS to be done. Then you can decide what to do from there.

The disappointment of the loss of your friends help cannot overshadow the reality of the what it costs to do the motor right. just trying to keep you from a bigger disappointment of the risk of your rebuild turning out worse than it was before for the sake of a few $$. Just keeping it real.

[Lazeum]

I was having the same situation 1 year ago. I decided to do it on my own. Go for it, it is rewarding project.

As everybody said, you need some tools, from the list above, I would add a dial indicator also & some gage feelers.

Read at least 3 times "how to rebuild your OHC Nissan engine" & get a FSM next to you.

For the process, I've torn the whole engine by myself, including oil plugs. I put everything in bags, keep also all pieces in order to make sure they will match again once you'll have to put back everything together.

I then brought the crankshaft, the block & pistons to machine shop. They identified my block as in need to be rebored, surfaced & piston clearance to be out of specs.

Machine shop took care of the block & crankshaft. They machined everything back to surrounding parts such as new pistons since I had to change them.

They removed every plugs from the crankshaft to clean up the galleries & installed new plugs. They also milled the pistons to get proper pistons to head clearance (I'm running flat top with P79 head). Measurement was done by myself, I went many times with parts to the shop, take one nearby.

I got everything back at home & did the full clean up & assembly by myself.

A lot of measuring needs to be done during the process: rings gap, bearing clearance, pistons height vs. deck, crankshaft fore/aft. lash, etc. There's no shortcuts here. Take notes about everything you do & take pictures of everything even if it is obvious.

Total cost for your info was 1,000€ for machine shop work & around 500€ for parts (new oil pump, new squill shaft, new bearings, rings, pistons, gaskets, paint, new hardware) + dedicated tools (ring compressor & pliers to install/expand rings). You could take the same costs and put a dollar sign to get an estimate from the US (especially since all parts comes from the US + shipping)

Total time in hours from start to finish was around 250 hrs (2 months working only during weekends), I took my time to do it right. I've cleaned every aluminum parts with sand blasting followed by ball beading. I also replated the small steel pieces such as the hooks to lift the engine. restored the oil pan also.

I would not be cheap on small stuffs that matters (even if it could be overkill) such as rod bolts (ARP kit is $45) or head bolts (ARP at $120), compared to project cost, I believe it is ridiculous to do not do it.

I would also purchase new hardware elsewhere. Get all your bolts, measure them all with a caliper & pitch gage (they are all regular metric thread pitch bolts on engine), make a list and get new hardware (bolts + washers).

Grade 8.8 is fine for all the hardware except the one around crankshaft. Those details will make sure you won't have problem afterwards, those details are also important. If you need a starting list, I might have mine somewhere but I've made many mistake during the order (but I ordered extras just in case which were very handy).

Total cost for the full set was around 35€; ridiculous also to do not do it.

I've been lazy and I did not share my build in English (only in French :stupid: ) but here's the link if you'd like to see some pics. (Google translator could probably translate most of it)

The engine runs for 600mi since rebuild (and went to Le Mans Classic ) , it's very nice feeling (and quite unbelievable!!!) to hear it starting every time I turn the key.

It is MY engine now

Bottom line, do it!

Edited July 25, 2012 by Lazeum

[Ben's Z]

Well taken. When I took my current N/A motor's exhaust manifold in to be true'd up I asked the shop what a head job would cost on the "6", he said right around $250. Not sure if that includes getting the for wipe pattern within tolerances. I am not trying to avoid all the costs, I know the machine work is the money heavy part, those guys have thousands tied up in their equipment.

Remember that most of what the rebuilder charges for is work you CANNOT do at home. High precision measuring to determine what NEEDS to be done, then if needed, boring, sizing, straightening, etc. Yes you can re-assemble it instead of the shop to save money, but that's not much % of the total cost.

You cannot not just replace rings and bearings with stock sizes, run a hone in it, and clean things up to re-assemble and cross your fingers. Waste of time and energy. The engine is in better shape than that right now probably. You MUST pay the shop to at least evaluate things and let you know what NEEDS to be done. Then you can decide what to do from there.

The disappointment of the loss of your friends help cannot overshadow the reality of the what it costs to do the motor right. just trying to keep you from a bigger disappointment of the risk of your rebuild turning out worse than it was before for the sake of a few $$. Just keeping it real.