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So begins another project for me. I tend to only build the wild and crazy stuff, as everything else tends to bore me these days. I've been working on this one for a while already, but it was finally time this week to move it into the clean room, and begin the first mock up assembly of the short block.
The engine started life as a 1990 C2 964 base with 40K miles. While this beast is based from a 964, it won't be finding its way back into a 964, or any 911 variant. It will be fitted into a very special Beck 904, and because of this, the engine will have several unique twists.
Externally it will look much more like a vintage 911 engine, and I am making special preparations to the crankcase, and all hardware to help the engine better fir the character of the car. All the hardware has been yellow zinc plated, and the crankcase has been dulled and cleared a bit to have a consistency more like a vintage engine would have. A resin fan shroud will be fitted, and instead of the engine ancillaries being cluttered with EFI components, atop this engine will sit a pair of very large, and highly modified PMO carburetors. Ignition will be via direct fire, so the absence of a distributor won't look very vintage, but it will remain clean.
Internally I have retained an OEM 3.6 crankshaft, but all other internals have been addressed with overkill engineering from A to Z. You will find the approach that I have taken to the modifications to be a bit unconventional, this is especially true with what I have done for cams, and ports, along with valve sizes, and flow margins. Pushing a car that will weigh in wet @ 1800 pounds, the engine combination requires quite a bit of alteration, and the addition of carburetors to this engine further changes up the engine combination.
Why not EFI? I'll answer that question before its even asked! It boils down to simplicity, a vintage feel, and what fits the character of the car more than anything.
I will post extensive photos as I complete the build. There are a few areas of proprietary concern that I won't be sharing photos of.
Its been almost 4 years since I have built one of my 4.1s, so I am greatly looking forward to waking this combo up again, and seeing what I can do. The 904 is an ultimate platform for this beast. No doubt!
I am still finishing the head work, and awaiting the cylinders to be delivered from LN Engineering, so I'll likely build the bottom end, then have a bit of a break before I end up finishing assembly. The heads should hit the flow bench in 3 weeks.
I have two more similar builds to this one planned over the winter. One of them will be for my recently completed 964, and the other will be for an RSR clone. Both of these will be EFI versions. The engine being built for my 964 will be a high torque configuration.
Here are the first round of photos, as I began mock up assembly, and finished ultrasonically cleaning the block, after soda blasting it.
Soda blasted 964 crankcase after a bath in hot ultrasonic solution.
Its almost time to tango!
Full ARP hardware kit, cryogenically enhanced.
PC-3 coated main and rod bearings. Auto Verde billet oil pump.
Custom forged pistons in 106.7mm. These pistons will see skirt coatings, ring land coatings, and thermal barrier coatings after they are balanced, fitted and modified.
ARP hardware
Iwis Motorsports chains, cryo enhanced
Rauch & Spiegel billet #8 main bearing
Last edited by Flat6 Innovations; 10-09-2015 at 03:00 AM.
I am doing a similiar build, but going with 4.0 (Turbo) and using the LN Engineering parts. I am still waiting to see if I need custom pistons or not. I am running GT3 RS 80.4mm crank and have 102mm cylinders from LN. Do you know if any standard pistons fit? So far I only have 3.8 RSR pistons, but dont match the rods I have here.
I am doing a similiar build, but going with 4.0 (Turbo) and using the LN Engineering parts. I am still waiting to see if I need custom pistons or not. I am running GT3 RS 80.4mm crank and have 102mm cylinders from LN. Do you know if any standard pistons fit? So far I only have 3.8 RSR pistons, but dont match the rods I have here.
changing stroke, or rod length will usually call for altered pin heights. I have seen people add stroke, then make a custom rod, that counter acts the additional stroke, keeping the pin height standard. That's not something I'd even consider.
I had originally planned to make this one a 4.4, and add stroke, but for such a lightweight car, I decided to keep the stock stroke to increase throttle response and a broad power band.
Porsche is also going that way. The rods seem to get longer and longer on newer engines. 127mm to now 130mm on the later Mezger engines. We are trying to get the 130mm rods to fit. How long are the ones you have in your 4.1 engine?
Porsche is also going that way. The rods seem to get longer and longer on newer engines. 127mm to now 130mm on the later Mezger engines. We are trying to get the 130mm rods to fit. How long are the ones you have in your 4.1 engine?
The rods in newer engines are longer to increase dwell time at TDC, due to DFI and it's higher combustion chamber pressures. We've been developing 9a1 engines since 2010, and have taken them to 4.2 liters, and 450HP on pump gas.
With this build, since I retained the stock stroke, I also retained the factory rod length, as I tend to favor the rod ratio this gives for such a lightweight car.
Cool beans, Jake. Can you post pics of the Beck 904? You work on Ferrari too?
The car is a Beck GTS, it's currently in assembly, but will look similar to this when it is done.
Beck 904 GTS
Yes, I do Ferrari engine work, too. Thats my Testarossa in the background, though. I have it's engine out for a "Major" right now.
Before... The engine had never been out of the car, since 1992!
The rods in newer engines are longer to increase dwell time at TDC, due to DFI and it's higher combustion chamber pressures. We've been developing 9a1 engines since 2010, and have taken them to 4.2 liters, and 450HP on pump gas.
With this build, since I retained the stock stroke, I also retained the factory rod length, as I tend to favor the rod ratio this gives for such a lightweight car.
I talked to my engine builder about this as well, since my car is going Turbo, we are uncertain at what point the longer rod (thus duration at TDC) will bite us in the butt.
Thank you for the info on the rod length. Gives me some food for thought. Also, why are are you sing such beefy rods on an N/A? Whats the weight on those? I favor the GT3 Titan 130mm rod at this moment... Do I have a completely wrong train of thought?
Why such beefy rods? I believe in overkill. This engine will spin over 8,000 RPM with the cam/ head combination that I have developed for it. The rods have been internally lightened further than most using the same H beam design.
I have a set of 130mm Pankl Titanium rods that I could use for it, but they have a max service life well below the rest of the engine, so I saved them for another day.
Rod length is effected by/ effects so many things, and the entire engine configuration must be considered when choosing rod length. I fond that for an NA engine, with a stock stroke, its difficult to beat the factory rod length from an overall perspective.
This will be a street car that will sometime make it to the track, which changes things up, too... With your turbo build, most everything will vary from what I'm doing here.
Wow, 8k redline seems very optimistic with stock 3.6 crank. I don't think I've seen any other builder recommend sticking with the stock crank over 7k.
Looking forward to the results!
I was tempted to replace it with one of my billet units, but the lightweight vehicle changed my mind a bit. The crank may be a factory unit, but its not "stock", as I have cryo enhanced it. I have also altered the oiling passages a bit, which is one of the major benefits of a billet crank. I am one that believes that some factory items are superior platforms for modification, with some work.
The car won't need 8K RPM to make its power, so it will rarely go there. The valve train is good for way more than the engine will ever practically see.
If the car would constantly see 8K RPM, or was a full track car, or pushed a heavy 964, I'd certainly be using my billet crank.
Made progress last night... Set all my bearing clearances, and installed main bearings. Mocked up the 996TT oil pump with the intermediate shaft, and needed to do slight clearance work to make it just right. Took the time to disassemble and true the layshaft/ chain sprockets.
Now I'm ready to dynamically balance the rotating, and reciprocating masses, which I will do on Monday. Then it's time to move forward with short block assembly.
10-09-2015, 02:35 AM
4.1 Flat 6 Innovations 964 Build Up Pictorial
