924Board.org

[Tun'd Up]

Hello everyone, I am new to this forum and I'm new to using forums in general so forgive me if I don't know to do basic forum stuff lol. But I bought a 1980 924 turbo a couple of years ago and I've been doing work off and on on it for a while now and I've come to a stand still with the engine block at the moment. I'm starting this post to help keep myself a little more accountable and try to finish this project up and maybe start on another project. My initial plan was to get it running first then upgrade later on, but that ship has sailed. So my vision now for the car is to rebuild everything from top to bottom and make sure everything is nice and proper. I would like to do an EFI conversion, add an intercooler, upgrade the cooling system and brake system and some other mods. But I hardly know much about modifying things on a car or how to make things work. I'm sorry in advance if I ask any questions that have already been answered over and over but If you can kindly direct me to a thread that has exactly what I'm looking for that'd be awesome. I will be posting videos on youtube as well to try and track my progress and maybe you will get a better idea of things.

So a short background story about the car, I picked this car up from a guy out in the middle of nowhere in the country. Super nice guy but he bit off more than he could chew with it and let it sit for several years. Based off of his story he said it sat for 14 years when he purchased it. The license plate on it showed it was last registered in the 90's. Upon first look of the car when purchasing it I found the what looked like a rats nests in the engine bay. The interior looked like it could be freshened up and a few things recovered. The hatch was stuck shut. And the guy told me the transmission was stuck in first gear and could not shift. After working on the car for a while I've discovered a lot more problems with it than initially thought (as expected) but I'm not giving up so easily. This car is forcing me to learn a lot more than the average guy working on a car.

So fast forward to now and some of the problems on this car includes rust, fuel tank leaking, leaking water inside, transmission rebuild, full interior restoration, hard to find/outrageously expensive parts, parts that are no longer made, full engine rebuild, etc.

Here is a couple pictures of the car recently and I'll post more pictures of the car later and what problems I come across and what I have done to fix them.
https://imgur.com/XhogB6c
https://imgur.com/j0JKCMS

Yes the car is outside and I need to put in a garage but I am working on that at the moment.

On to the engine, so the head has been completely redone and turned out perfect. Did not do any modifications to the head. The crankshaft is in great shape too. The block however is a different story, apparently cylinder 1 is the worst one and is just outside of clearance and piston 1 has a lot of wear on it. I don't remember the measurements he told me over the phone but I planned on meeting in person with them and talking with a certain guy at the shop I took the block to to figure out what I should do going forward. They're an old school shop who have been in business over 40 years with American engines and some foreign. They're scratching their heads with this just as much as I am on it but if they have specs and what not they will do it. I am leaning more towards buying custom or off the shelf pistons and rods. The only problem is I have no idea how to custom build an engine and how to make stuff work and what I would need to do if I change things like compression ratio, stroke, bore, etc. I'd like to take the path of least resistance when it comes to this, but I am open to some slight performance gains if someone has already had it all figured out. I'm hoping maybe someone can tell me what exact products they have used and the specs on those products and what specs they have went with for stroke, compression ratio etc etc.

I'll try to give regular updates on here about the car and more information about it.
_________________
Porsche 924 Turbo - Current Project

[safe]

Figure out how much you would need to over bore the engine, if its stock at 86.5 mm, 87mm is probably enough.
Talk to ebs racing about a custom set of JE pistons with the size you need. When you have the pistons you have the machine shop bore the block to suit the pistons.
For a restomod you might want to and an intercooler to spice up the boost a bit. I would raise the compression a bit from stock with new pistons.
EBS also have the bearings you need.
_________________
/Magnus, Stockholm Sweden
=======================
Porsche 924 -79 NA, EFI and Turbo.
Porsche 931 -79
Porsche 911 -77, 3.2 Targa
Porsche 911 -69, 3.6, Coupe

[safe]

The rods are heavy, but strong and if you don't have to rev it above 7000 they will be fine.
You can save a lot of weight in the rotating assembly with custom piston and rods, literally a pound per jug, but it must be worth it too, depends on your goals.
_________________
/Magnus, Stockholm Sweden
=======================
Porsche 924 -79 NA, EFI and Turbo.
Porsche 931 -79
Porsche 911 -77, 3.2 Targa
Porsche 911 -69, 3.6, Coupe

[924RACR]

As noted - get new pistons, bore to match. I agree, call EBS, they know their way around these motors and what you'll need. I've been working with Don Weaver there, most recently.

Regarding modding the motor: it's a turbo. The biggest gains will come from boost, intercooling, and fueling. Normal internal tweaks are less important than they would be if it was NA.

Consider ARP head studs, though, to help contain that boost.

Could consider higher compression ratio, though, with intercooling added and pistons being needed. That'll particularly help the low end.

Microsquirt conversion will likewise help all that work well.
_________________
Vaughan Scott
Webmeister
'79 924 #77 SCCA H Prod racecar
'82 931 Plat. Silver
#25 Hidari Firefly P2 sports prototype

[kondzi]

Best of luck!

Start with
https://www.924board.org/viewtopic.php?t=22724

if not already known to you.

For the EFI conversion there are also posts of forum guys doing their conversions in different ways. There are many ways to do it, some very expensive, some more affordable.

Do you have any knowledge about electrics/electronics? THat will be useful if you want to do the EFI conversion by your own, or maybe you want to ask someone knowledgeable to do it for you?

Do a list of mods you want to do and post it here.
Do a list of thing you need to rebuild and keep stock.
Make a plan, move forward bit by bit, not all at once, post your progress / doubts / issues here
_________________
---
Konrad
'89 951 US
'88 Mustang 5.0 LX Convertible (factory specs)
'84 911 Carrera 3.2 RoW (factory specs)
'81 931 RoW (TBD)
'81 Ford Capri 2.8i (factory specs)
'79 Ford Capri 2.9 (heavily modded)

[safe]

Yeah, EFI is the best upgrade you can do. Maybe close 2nd after intercooling on a turbo.
_________________
/Magnus, Stockholm Sweden
=======================
Porsche 924 -79 NA, EFI and Turbo.
Porsche 931 -79
Porsche 911 -77, 3.2 Targa
Porsche 911 -69, 3.6, Coupe

[Cedric]

[kondzi]

Well in my case I've rebuilt K-Jet and then appeared the DITC was failing.
Having said that EFI'ish conversion I did with K-JET in place I'm doing only spark with MegaSquirt.

Cedric do you know how much HP stock K-JET can handle? I'm sure it is quite powerful in fuel delivery...

If I have not rebuilt K-JET firs, I'd switch to EFI due to much easier diagnosis and availability of parts. But I'm a DIY guy, so I don't count labor, which might be a big portion on the bill.
_________________
---
Konrad
'89 951 US
'88 Mustang 5.0 LX Convertible (factory specs)
'84 911 Carrera 3.2 RoW (factory specs)
'81 931 RoW (TBD)
'81 Ford Capri 2.8i (factory specs)
'79 Ford Capri 2.9 (heavily modded)

[safe]

[Tun'd Up]

My stock bore is 86.5 mm and I'm going to step up to 87 mm. I just spoke with Don at EBS racing over the phone today and he said he will get back with me on getting a set of new pistons and rods ordered. I've read some more about what some others have done with this engine. My main goal with the car is not a huge HP monster but a nice Sunday driver that I can press the gas and get a little kick out of every once and a while. I thought about bumping compression ratio up to 8.0 : 1 or 8.5 : 1. But don't know if that will cause any issues for clearances on the valves or anything and if I need to adjust anything. I will look into ARP head studs and other fasteners.
_________________
Porsche 924 Turbo - Current Project

[Tun'd Up]

[MikeJinCO]

Hayes Lewis is working on getting rods made, find him in the racing thread. Doing pistons also, but not turbo. Probably much less expensive than Crower for rods

I just got my pistons ordered thru EBS they are 12-1 on a 931 head(no turbo) and delivery 10-12 weeks.

The rods bolts For an Alfa GTV 2000 will work in the stock rods, the splines and head are not the same as stock rod altho they assemble snug due to the center larger diameter of the bolt where the rod sections join. They will not be quite as precise as the correct bolt. They are made from 8740 so better than stock(12.9 stl), but not as good as the ARP2000 ones. Several years ago Porsche made another run of the stock bolts, when I called they were about $25+ each and had to be ordered from Germany.

I bought a set of the Alfa bolts just to see what they looked like and assembled a rod with them. I they took it to my machinist who said they would work, just not quite as precise as the stock spline fit,
_________________
Mike


'67 MG Midget Dp
'71 Ocelot Dsr Kawasaki 1000(under rebuild)

[Carrera RSR]

[Carrera RSR]

[Carrera RSR]