marinesniper0318

1988 - Porsche 928 S4, 130k miles

I need some advice, I have 3 ideas, one of which I like better than the other.

1) buy the 5.0 short block new and build a new motor up with new parts.
- benefit, I can still drive my current 928 while I am doing this and I can go at
my own pace. I plan on this to be a 6 month project.

2) Or start replacing parts on my exhisting like the Alternator, A/C system,
injectors etc...

3) buy the 5.0 short block, built it up, while doing this drive my 928 and replace
top end parts like the alternator, injectors, valves, cam, etc...

My goal is to have a near new engine (with some rebuilt parts for cost savings) as possible. I dont plan on building a stroker motor, maybe S/C after I am done...

thanks...again I am not highly knowledgable in the mechanical area but am learning and willing to make mistakes in the learning process.

I left out electrical because that is something that will be ongoing and I will be replacing/repairing as I go.

thanks...

marinesniper0318

Sorry should clarify some more:

2) basically rebuild my current engine

3) basically build up a new bottom end, while doing this replace top end parts and at some point merge the new top end parts with the new bottom end and put the completed engine back in the car....

I hope that clarifies my first post.

ender928

Did something happen?

SeanR

Why mess with it at all right now?

Go buy another 5L and build it up, then swap out of you feel the need to.

EspritS4s

Building up an engine from new parts is going to get really expensive assuming you can find the parts. Most would have to be rebuilt parts. The bigger question is why?

ender928

If the need is to have your engine in the best shape before you supercharge it then im sure someone with experience can tell you what you need to have in perfect condition before you do so. But if its running fine now I think thats unnecessary.

Lizard928

Do the maintenance, and drive it!

All you people who are so concerned with mileage. I dont understand you! These cars are much happier getting driven every day!
I have 230,000 MILES on mine, and I will be boosting it very soon!

Frank Castle

All sage advice. Only thing on your list that sounds like it might need to be addressed now would be servicing your A/C system - but we don't know the current state.

blown 87

If by rebuild you mean replace all the seals, hoses and rod bearings, and a full timing belt service, then yes, do it.
If you mean take it down to the bare block, not much reason to do that unless there is a problem.

The first option is only really expensive, the second option it one of those "You got to be freaking kidding me deals"

A full rebuild using OE parts and quality machine shop work is going to be around ten grand in parts and machine shop charges.

LEADASS

Personally I was thinking the same thing. When I bought my car I thought... Rebuild it all! I even bought a spare complete motor (928 Intl. December half price sale!!!). Now that it's been a couple of years, and I actually started to listen to these guys, I think if she aint broke let her go. I'm now rehab-ing every system I can to keep the current motor going forever. By the end of this month I hope to have all the heavy lifting done and then just drive it for five years til I have to do it all again. I still like the idea of the spare motor( just in case).

Bill Ball

Although some people think these motors are not very durable and need rebuilding at 150K miles, I don't see that. Unless you do a few really nasty things which will break them, all you should need is regular maintenance and attention to some seals when indicated (by oil leaks). I've done the pan gasket, rear main seal and cam cover seals when they were found to be leaking, but otherwise just prescribed maintenance. My front main seal may be starting to leak and possibly the oil pump seals. I'll do them for the first time with the next timing belt job later this year or next year when I reach 250K miles.

cpayne

+1
165K on mine of which I put 6K since i purchased it last August. Some stuff to work out, but man its got pull . My main inspiration is Bill ***** mileage and the video in his signature. I think he had well over 100K when he SC his car. Amazing cars meant to be driven.

U-928

I'm in the middle of undertaking your option #1 for the same reasons. Only I'm going from a 4.5L to a 4.7. In addition, my reasoning was that this car was a used purchase to me with absolutely no maintenance history, and it leaks oil from every possible orifice available. It also lets me port and polish the heads, and get everything to 100%, as I like all my cars. I did buy a complete used motor though, and the only downtime I'll have is to yank the motor out of the car so that I can steal it's OB square timing belt gears.

Mrmerlin

U928 instead of swapping out old square tooth drive gear for the belt,
see if you can get an updated set with the HTD belt this belt has round teeth and this must run with round tooth gears

Mike B

I'm thinking..."If it's not broken, why fix it". Do the maintenance...absolutely, but start rebuilding a motor that doesn't have any issues has me confused. Do you have engine concerns / problems?