im4duke

Recently replaced plugs and wires and decided to perform warm leakdown while in there. Here are the results:

#1 8%
#2 26%
#3 16%
#4 80%
#5 26%
#6 8%

I know, pretty ugly.

#4 leak is on the intake valve. Typical steps were taken to ensure valve wasn’t stuck open. No such luck. #’s 2,3, & 5 clearly want some attention too.

So, if I’m going to open it up, I might as well get what I want out if. Let me define that: around 500 rwhp for 80% street and 20% DE/track/AX. Keep my AC.

FYI, it supposed to be a Ruf 3.4 with upgraded cams and fueling, but I cannot verify it at this point. Car has 38k original miles.

Looking for ideas, suggestions, opinions on what to do. At this point I am considering variations on the following options:
Although time is not an issue, cost is. That is, I don’t feel that I need to invest $20k to meet my goal. For example, the Protomotive engine linked to above is $12.5k. I could install that and probably sell or part out my engine to recoup a fair bit of it. In my mind, that would be financially more prudent than building my own super-duper engine for $20k+. Just an example of my willingness to consider all options here.

Anyways, would love to hear what you guys think would be the best direction.

Thanks,
Maxx

PT

I'm not sure what budget you are looking at but given the numbers, I'd be tempted to do a complete rebuild just so you know that the bottom end is not as bad as the top.
I'm in the process of rebuilding mine and going EFI. I think depending on what EFI computer you use and who does the work, your budget be significantly less or more than 20k. Of course, there's also the what else is needed on the "base rebuild" - new P&C, springs, valves, crank, ...?

senna21

Sell the children.

125shifter

I'm wrapping up my engine rebuild and EFI conversion. If I had it to over, I would seriously consider sending the engine out. I would probably send it to Henry at www.supertecperformance.com

I enjoy building an engine as much as the next guy, but with the added time involved with the EFI it would have shaved months off my project by sending the engine out.

Since my engine had been apart before I chose to take it all the way to the crank to make sure it was right.

The obvious items for a 930 rebuild are ARP rod bolts and head studs (or similar), piston rings, and performance valve job. If the pistons are bad and you already have fully finned 3.4 cylinders, you can get new pistons and have the cylinders re-coated. Of course while you're in there it'd be nice to go twin plug and open the intake up for the Carrera manifold.

DonE

It's hard to say what has been done to that motor you reference above. I would want to know specifics before I consider it. That being said, on the surface, that sounds like a good deal.

In any event, I just rebuilt my motor and converted to EFI, so I have a good idea what it will cost you. There are only a couple of special tools you need, so that's not a big concern. In fact, I borrowed most of the specialty tools from the local garage.

Here is what I did:

custom intercooler, 98mm pistons and cylinders, ARP hardware, 964 crank, super C2 cams, electromotive EFI and spark system, 72 injectors, T61 turbo, custom plumbing for fuel, air intake and intercooler, 3.2L intake, stock 3.2L fuel rail, EBS rebuild kit, head porting, coatings, various silicone hoses and tubes, TIAL wastegate and BOV, Accufab 75mm throttle body and lots of misc parts.

I did all the disassembly and reassembly, initial tuning, welding, and on and on. The entire project cost me $18,000 in parts and I sold my old parts for a little over $9,000. It took me 6 months to finish, with most of the time involved in custom fabricating brackets, fuel lines, wiring and intake plumbing. The wiring took the longest.

The upside - I saved A LOT of money, I learned A LOT about my engine and EFI, I got A LOT of personal satisfaction in building a hot motor, and made a lot of good freinds (other builders) along the way.

The downside - listening to all the opinions on how to spend my money, buying an electromotive unit, lots of trial and error (aka, pissed away money), as tedious as building a house.

Would I do it again? In a heartbeat with two changes - the EFI system and the turbo.

38D

So if you had to do it again, what would you choose instead?

DonE

ECU - Motec - expensive, but LOTS of support and great track record (no pun intended)

Turbo - a hybrid made to my motor's specs - like a T-61 compressor, O trim wheel, .78 AR, T4 flange

PorschePhD

You are going to need EFI to achieve those numbers. You will also want to address the issues of headstuds, rods or rod bolts, guides, springs and so on. Carefully measure every journal and bearing during assembly and check and double check everything, deck heights, end play, etc.

The EFI has many options. The one thing to keep in mind that to do it correctly you need access to a dyno that will steady state and a lot of patience. Part of the process is the break in, the dyno and fine tuning it on the street. If you are looking for a project and are not afraid of time, patience and some hard work then dive right in. You will have a blast. This is how I got into the business. I was always opening up a motor on my cars to change this or that, or simply try a new set of cams. Hell, if someone told me a circlip was better than the next I would open my motor and try it for a data point.

If this is not something you want to mess with then leave it to the professionals and make sure there are warranties involved and have them build what you want, not what they think you want.

im4duke

Thanks for the responses guys.

I am playing with the idea of doing the rebuild myself. If I go that route, it would truly only be a rebuild with "bolt-on" upgrades likes bolts, studs, springs, cams, etc. With B&B headers and a K27HFS, I’m guessing that would generate around 400hp.

My local shop is very supportive and has offered to kit the engine for me. That is, I disassemble, they measure, machine, etc. and give me back a kit to reassemble. They'll do as much or as little as I want them to do. That way I could get some satisfaction in doing some of the work myself, learn a lot about my engine and save a little money.

However, I am very tempted to go EFI. I’ve spoken with a couple of shops and received ballpark estimates on the conversion costs for EFI vs. the carrera manifold. From what I am told, they would cost me about the same money. EFI seems to be the better solution hands down. Of course, this just about doubles the cost of my rebuild. I am pretty sure I don’t have the skills Don and David have to undertake this myself.

Again, my other option is to buy a used performance engine like the Protomotive unit I linked to before. Assuming the engine is what it is said to be, I might be able to buy it for $10k, upgrade the EFI for another $5k and sell my engine for $7k (unverified #’s). That would land me a 550-600HP engine for around $8k. That’s very tempting!

How does one go about checking out an engine like this? It’s out of the car already so I can’t run it. I could find a local shop in NJ to check it out or I could pay to have it shipped to a shop I trust and have it inspected as well. I plan to call the Protomotive shops and see if I can get the build sheet.

Any other thoughts?

PorschePhD

Using the Carrera intake will yield a lot more hours then something that uses the stock intake. The stock intake can be cleaned up enough to be used. The Carrera intake requires throttle body changes, welding the intercooler, custom pipes, custom attachments and so on. You have to be able to weld aluminum or be good enough to jig everything and take it somewhere. That is difficult to do and have it fit.

On the motor, careful picking up something used. You will want to do a leak down if you can and do a visual inspection. Even scope the cylinders if possible. Buying a used turbo motor is sometimes tricky and can be disastrous.

sand_man

Being that my car's engine had low mileage and excellent compression and leak down numbers when I bought it (passed PPI with flying colors) and has now hit the crapper from only a few months of driving, I'd advise against buying a used engine!

Sameer

IMO the stock intake is good upto 550-600bhp. There have been cars producing these numbers with the stock intake. Check with Chris Carol of Turbokraft, he has it on paper. If you want more than go the 3.2 carrera intake.

BrianKeithSmith

I'd like to see the breakdown on those numbers. I sure couldn't convert mine for that, and I did all the work myself and went with one of the cheaper ECU's.

im4duke

Brian, $5k was the low end suggested to me for replacing CIS with an EFI kit while doing a complete rebuild. Was told that it would essentially be hardware and some tuning costs. Install supposedly would be a wash. ECU was unspecified. I suspect that most people reading this would think that it's unreaslistic or a "get what you pay for" deal. I would have to agree.

Nevertheless, my inclusion of that number was out of context as I wrote that it was $5k to convert the Protomotive engine mentioned earlier, when in fact that should have been more like $9-10k. Then, the potential of that purchase and conversion is significantly less attractive.

In any case, I am likely facing a $6k DIY rebuild (expensive upgrade parts included) or a $12k shop job with EFI being a $10k option.

Sandman, maybe we can find a 2 for 1 deal somewhere!

Sameer

Maxx,
Which ecu you going for?