Motor rebuild: list of items and cost, suggestions?

[Healey Z]

I'm resigned to the fact that the motor needs to be rebuilt. The car is a blast to drive and deserves a fresh motor and some new syncro's in the trans.

The motor has N42 block / N47 head motor and is fed by dual 32/36 webers, pertronix disti.

I met with a machine shop that has done a few small block Fords for me and have always done a great job.

First question. Is this a decent motor to rebuild?

I am reasonably happy with the performance of the current motor, but if there is an easy way to pick ups some performance, without trading reliability, I'm open to that.

Here is a list (from my notes) talking to them about what they would do to rebuild the motor. Their cost is $1500 and would take a few weeks.

Second question: Is there anything missing, is this a reasonable deal?

Complete disassemble and cleaned

HEAD

Pressure test head

Surface head

Three angle valve job

Cam sent out checked and reground

New valves

New valve guides / seals

New bearings

New timing chain

New timing chain sprocket

Reuse springs/keepers, lash pads, retainers/rockers

BLOCK

Magniflux block

Block checked and honed, bored if required

Crank checked, polished

New bearings

New pistons / rings

New oil pump

Reuse rods

OTHER

Resurface flywheel

Resurface intake manifold if required

Resurface exhaust manifold if required

Reassembly, adjust valves

Paint color of my choosing

Spin up engine on stand verify compression and oil pressure

No water pump

Edited December 19, 2010 by Healey Z
sppellling

[Bruce Palmer]

Sounds very reasonable to me. I'd think $400 per hole would be about the norm for a job as in depth as what you've outlined.

[Diseazd]

If you're not using new rockers, I wouldn't have him regrind your cam. Cams in a stock Z engine rarely have any noticeable wear, and if you do regrind, you probably should install remanufactured rockers to seat in with the new cam.If you don't regrind, make sure he keeps the old rockers numbered, so each goes back on it's existing cam lobe. Re price.........he isn't going to make any money at $1500.00. It's an excellent price! (don't forget a new chain tensioner)

Edited December 19, 2010 by Diseazd

[LeonV]

HEAD

Pressure test head

Surface head

Three angle valve job

Cam sent out checked and reground

New valves

New valve guides / seals

New bearings

New timing chain

New timing chain sprocket

Reuse springs/keepers, lash pads, retainers/rockers

I don't see the need to reground the cam, it's a very durable piece (just like the rest of the engine minus the rod bolts). Maybe it's a Ford thing to do.

They should make sure that all valvetrain parts are reinstalled at the same lobe that they were previously on, or else you will have wear problems. No need to resurface anything if there are no abnormalities found, and you're going for stock. If you ever plan on winding the engine out, get some ARP rod bolts. It's cheap insurance.

Also, there are no bearings in the head that they can replace.

[Healey Z]

Thank you for the replies. I made some notes to discuss with the engine builder. Since they send the cam out to a specialist, hopefully they know what they are doing.

[Zedyone_kenobi]

I am not sure what year car you have, but I would say that perhaps you could forgo reusing the stock cam. If you would like to increase performance, you could easily just put a very mild +1 type of cam in there. You can get a cam kit from MSA or other reputable parts company. Or, if you are set on keeping the stock cam, what about a mild piston upgrade? If you like the attitude of the engine, but want more HP, then a MILD compression ratio jump would be nice.

I would assume as part of his work he is going to clean and chase all the threads, flush out everything, etc. I also guess he knows to put in hardened valve seats so you can safely run unleaded gas.

I would give the folks at www.advancedistributors.com a call. They recurved my dizzy and I love it. Also a nice rebuilt set of SU's would be sweet on that pretty new engine.

[IdahoKidd]

I just pulled my records for my last build in 1993. It was complete, reground crank, new cam, new pistons, etc etc. It was $2850 but did include a new clutch and pressure plate. $1500 sounds cheap. I guess mine did have the engine RR to...... (records were from previous owner) so maybe not if you are doing the labor yourself. Be sure to ask if they will warranty their work. A single loose rod bolt or any other component can mean big bucks in a hurry.

[Healey Z]

Again, thank you for the replies. I will be removing and reinstalling the motor, so the $1500 is just for the machine shop work. Yes they do the standard "boil" out the head/block, chase the threads, hardened valve seats, new freeze plugs...

I looked at a little bump in cam, but for $799 for the cam kit and $224 for the cam, tax and shipping...I would be at $1150....ouch, a little too much for a few more ponies.

I will however be changing the pistons anyway. I've heard that by going to the flat top pistons it will raise the compression to about 10:1, but I have also heard people can have some pinging problems. Is there a piston that is somewhere between stock and the flat top?

I also agree with the disti curve verification, a lot of potential can be lost there.

[tlorber]

I agree that bumping compression up a bit would be good, but you are smart to be cognizant of it getting too high. My roadster has a shaved head and it pings under load on hi oc pump gas when it gets warm. This means I have to back the timing off more than I'd like. My Z has dished pistons and someday I may look into going to flat tops, but I really don't want to be using anything higher than "premium California gas" (an oxymoron if I've ever heard one).

There are quite a few variables that effect your dynamic compression. So, while you bump your compression ratio, installing a taller/higher duration cam will bleed off some of that pressure and may allow you to avoid pinging. Make sure you talk to a builder about this so you know what you will be facing.

[Travel'n Man]

I just completed a complete rebuild - fattened up my cam - increased my compression and new pistons,rings, rods........ - repainted the engine bay - my first recommendation would be to call Dave Rebello and discuss your complete project with him - he has some crazzzzzzzzy knowledge on our engines and a proven track record on the race track. Make the call and get his input - he can give you some guidence on your head - pistons - rods - compression - sell you a few parts or a lot of parts - he knows his stuff.

Edited December 20, 2010 by Travel'n Man

[Healey Z]

Hey Travel,

As a kid, I use to be in to 510's. The Rebello motors were the absolute top shelf way to go. I actually spoke to Dave the week afte I bought the car, before I started to make the current motor work. For a street perfromance rebuild on the long block (as I remember) it was $4-$5K. When you look at the cost of all the cam related parts and what you are getting, it may not be hugely out of line, but not in my budget.

However, perhaps there is something I could do, like a simple piston choice that gives me a little bump in compression. Thanks for the suggestion.