engine builder, engine rebuild, turbo Porsche, Uncategorized

Another IA engine build

Just a quick warning you might find the pictures below disturbing, I know everyone at the shop did.  So this engine was rebuilt by us just about 4000 miles ago and some how they managed to punch a hole in the front mounted oil cooler spilling out about every ounce of oil,  after we drained the tank and sump we got about six ounces out.  Despite the oil level gauge, oil pressure gauge, oil temp gauge, and dummy light once the engine no longer has oil pressure all reading nothing and the light shining ,  they continued to keep driving and from the damage that was done this was not a slow speed Sunday Cruise this had to be caused by high RPM’s HIGH boost and VERY high speed. 

after a full day of trying to disassemble of the upper half of the motor which is not very easy with the engine locked solid!! We then had to figure how to spit the case halves,  very difficult with a lock motor cause if you cant rotate the engine over you cant get the wrist pins off to remove the pistions we found that once the rod end broke it continued flying around in side the case and dammanged both halves of the case and the cylinder.  it also spun every rod bearing and made the main journals in the case eggshaped.  with metal every were in this case and oversize and egg shaped main journals the case will soon become a table in the shop or a very big paper weight! 

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After every thing was cleaned inspected and measured we ended up with a lot of scrap metal and very few usable parts, I think the heads are about the only thing that was not damaged.  stick around for the Start of the Build and we do have more pics i can put up it just makes we sick to look at this much damage.

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911, 911 Porsche, engine builder, engine rebuild, Porsche, Projects, turbo Porsche, Uncategorized

Continued 996TT motor build…the good stuff

Imagine you have built a very strong 996TT motor. All the things you have done in the past, knowing they work well. What happens if you make more power than you are suppose to? Imagine making 700+ AWHP on the dyno with the HP scale going up and up and all the sudden….well lets just say back to the drawing board. How do you keep the new motor together so that lifting doesn’t happen again. Well, like the bionic man, Steve Austin, we will built it better, stronger, faster….(enter music here) All joking aside this is a serious matter!

Lower end in these cars are fairly safe. We know what the limits are and almost never see a failure if the rules are followed. The heads and the cylinder assemblies are a different story. Like the early air cooled motors this continues to be an issue. In the air cooled arena we have been using what we call flame rings for years. This is an actual seal that is machined between the head and the cylinder so that if and when the cylinder head expands and lifts due to pressure and heat the gasket holds the integrity of the chamber together to avoid the cylinder or head or both from self-destructing.

 The 996TT is a different construction and design, but the problem still exist. Solutions are a little tricker. We start with the head studs. We increase the diameter of our already fancy upgraded head studs up another 3mm. We also change the material and thread pitch both on the head side and in the case. This requires yet more machining to allow these larger studs to be fit.

 

Second part of the process we grove the head to accept an actual ring. Traditionally the head gasket has a small crush ring that serves to hold combustion in while the sandwiched outer gaskets create a barrier for oil and water to flow through their proper channels. We take those same gaskets and stamp out what use to be the combustion crush ring allowing our new much thicker and precise ring to be fit. As you can see from the pictures this is a two part seal, the outer copper seal lays in the groove while our “special material” second ring lays inside the cooper ring. This ensures that there is multiple sealing surfaces to keep combustion in should the head lift again. This is secondary as our new head studs will hold it all together.

 

 

Added with new valves, custom springs, retainer and custom stem locks we start to create the base of a bullet proof monster that can withstand the unknown! Stay tuned for more on this project as we continue our journey.

911, 911 Porsche, engine rebuild, High performance rod bolts, Porsche, porsche performance, rod Bolts

Like anyone I was up bright and early to place the lower end of our monster 996TT motor together. Part of that process is placing the rods on the crankshaft. In most cases of factory rods engine-builders have been tightening rod bolts with a torque wrench and getting away with it. But in today’s high-performance world where we push engines to make a ton more power and spin at higher engine speeds, merely tightening rod bolts with a torque wrench is no longer the best way. In order to know why rod bolt stretch is a more accurate way to install a bolt, we have to get into a little bit of fastener basics.

 

 

Bolt Basics
A fastener works like a coil spring. As you tighten a bolt, it will stretch and generate a clamp load. The key to proper tightening of a fastener is to torque it until just slightly less than the bolt’s elastic limit. A bolt will stretch slightly as it is tightened. If you tighten the bolt too much, it will stretch beyond its elastic limit. If you measure a bolt’s overall length before you overtighten it, then again when you release the preload, the bolt will be slightly longer. This is similar to overstretching a coil spring. It does not return to its tightly packed position because the steel has been stretched and over-yielded. This is the bolt’s yield point, where it is permanently deformed. It’s the point just before it comes apart. The bolt’s ultimate tensile strength is the maximum stress imparted on the bolt before it breaks.

 

 

This applies to all fasteners, but it’s especially critical with rod bolts because they’re the most highly stressed fasteners in an internal combustion engine. With every revolution, the crankshaft yanks on the piston and rod assembly to pull it away from top dead center (TDC). The rod journal pulls on the rod cap, which tries to stretch the rod bolts. This stress becomes greater as engine speed increases since this load increases geometrically with rpm and forces the rod out of round, bending and fatiguing the bolt.

The key to keeping the rod cap on the rod is the amount of load created with the rod bolts. If the load created by the bolts is greater than the tension created by the crankshaft rod journal trying to pry the cap off the rod, then the engine will stay together. If the bolt is not properly preloaded (understretched) then the high-rpm tension is enough to stretch the rod bolts a very tiny amount with each revolution. This high-speed cycling of the bolt is similar to bending a paper clip back and forth until it breaks. That’s obviously something you want to avoid.

 

 

Torque vs. Stretch
The torque spec applied to any particular fastener is merely an estimate of the twisting force required to achieve the correct amount of preload or clamp load. Many times this is the only way to apply fastener load because the bolt threads into a blind hole like in the cylinder block. One advantage to the rod bolt is that both ends of the bolt can be accessed. This allows you to use a rod bolt stretch gauge. This is a specialty tool sold through companies like ARP that will accurately measure the amount of bolt stretch.

The procedure is actually quite simple. Once the connecting rod and cap are installed on the crank, start a nut on the rod bolt, slip on the appropriate-size box-end wrench, and then install the stretch gauge. Most high perfromance connecting rod bolts have a small dimple placed on both ends of the bolt that accurately position the rod bolt gauge pins on the bolt. Next, zero the gauge on the relaxed bolt. Then you carefully tighten the rod bolt until the gauge reads the appropriate stretch amount. For example, on this Porsche rod bolt the stretch was to be 5-7 thousands with no more than 65 ft lbs of TQ. We know that at 6.5 thousands we are at 58 Ft lbs and well within the meat of the spec.

Last but not least the bed in which the crank will lay…More on that later.

911, 911 Porsche, EFI, engine builder, engine rebuild, Forced induction, Porsche, porsche performance, Projects, turbo Porsche, Uncategorized

89 930 EFI Conversion returns

I hate to see any car we have built get into the hands of people that do not fully understand or appreciate the workings of a converted CIS to EFI turbo Porsche. This car was based on a 89 930, we quickly stripped the motor out of it and converted it to a 3.4 twinplug, Custom cams, large valves, headers, HF2 turbo and full Autronic SMC EFI system. We set the ignition up with M&W components, custom built the inlets off of the 3,2 NA intake fitted to increasedd TQ. The car originally laid apx 540 RWHP on our dyno.

 

 

After changing owners twice since I built it the newest owner who is a previous customer (we built his 79 930) showed up with it at our door. I had spent many hours with the shop in his home town trying to fix the issue. The issue was on going and kept the car from idling or running correct. Getting stuck in the middle of the intersection with a Porsche is never any fun. People will go out of their way to honk I swear.

We have a way we can read the computers and it was giving me several errors. All related to the cam and crank sensors. So I replaced the crank sensor and current plug system. We then upgraded the hall sensor to a much stouter version. This required the oil pump housing to be modified and fitted with the new sensor. Some more rewiring and the sensors were in. Additionally we rewelded the inlet pipe which was damaged when the car hit boost and pulled the line off, we also rewelded a bracket to the intake to ensure the originally integrity was there.

An oil change, valve adjustment and AC recharge and the car headed back to St Louis with a very happy owner. Nothing like a 830 cab that will walk sideways through 80 MPH!!

911, 911 Porsche, 993TT, 993TT Exhaust, engine rebuild, Forced induction, Porsche, Porsche exhaust, porsche performance, Projects, TT exhaust, turbo Exhaust, turbo Porsche

993TT Exhaust system, the rebuild continues

As we continue to move forward and bring the 993TT to its original glory and then some the parts keep coming in. While I will probably have to chance the configuration a little bit to accommodate the center outlet of the rear bumper. The design of the new Fabspeed system is phenomenal. What is most interesting is there are at least 6 configurations you can run with the full system because it is modular. If you look at the pictures and you are familiar with the TT exhaust you will notice that the position that the cats sit are detachable. This is so you can now run cat bypasses on the days you feel sassy. On the days you are in your Green mood you can place a set of  HJC high flow racing cats in. It is quick once the system is on the car, unboltt the v-band and remove and put the bypass or the cat in and you are ready! In order to get the air to the cats the velocity is picked up by changing the heads from a flat merge design to a triangular merge. This increase velocity of the exhaust gases as it is spun through the collector. This causes an increase in TQ but also lower spool times since the air is moving quicker to the turbo. Still equipped with heat the headers will continue to provide as factory unit did but with more HP and TQ. You also can not deny they look damn good too!

On my old 993TT (rest in peace) I went through several mufflers. My thought always was why not make something small. There is no reason to have these huge cans on the car. Well look at these!! Straight through cans that are tiny yet effective from making every neighbor mad within a 2 mile radius. Oh, believe me if they are sitting on the deck having some vino they will hear you coming down the street, but inside they will never know you have made it home. As far as the experience for the driver, well if you have a 993TTyou will just have to find out yourself =) These like the rest of the system are totally modular and can be fitted with a bypass all together if you wish. Alignment of the oval tips (another signature piece from Fabspeed) is not going to be an issue as they are fitted with several v-band connections to allow movement in any direction.

 

My old TT

 

911 Porsche, 993TT, engine rebuild, Forced induction, turbo, turbo Porsche, Uncategorized

A diamond in a rough. A rebuild of a 993TT

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Meet the new project of the family. This is our nameless 97 993TT. She is nameless because every name I come up with Roxanne doesn’t like. After all this is to be her car. We acquired this 993TT with 9K miles on her. Yes, 9K. Sadly enough someone thought they needed the car more and barrowed it. They didn’t take anything that would make them real money, rather they took things they thought might. Anything aluminum was removed or at least what they could tear off to be sold. They ripped bumpers instead of unscrewing them, cut harnesses and tore panels trying to get to the airbag. They took every fuse and relay in the car. We ended up with the motor but that is it. No intake, not exhaust. Nothing but a long block. The original owner and I came to an agreement and I purchased the car complete with a clean title.

In normal fashion I wasted no time coming up with parts. Some here, some there. The list when looked at is very intimidating. I immediately came up with an oil cooler, lines, AC condenser, fan and mounts. We still need to source an upgraded cooler. All in due time.

The motor we also were able to find most of the upper parts from LA Porsche. Thanks to Todd and Sara they will make it possible to complete the motor once and for all. The motor is also far from stock. It is a 3.8 liter with Carrillo rods, flame rings, o-ringed spigots and more. The motor on C16 can make well over 800 HP at the crank. Turbos were originally built and fitted. We will one up these and install GT3076s. They are rather large turbos but K24s with this type of build will be hard pressed to even make 550HP.

She is fitted with Bilstein sport suspension, monoballs, larger sway bars and a hand full of other goodies.

The body escaped most of the damage the interior suffered and various parts. The major damage was to the rear quarters. They chose not to unscrew the rear bumper rather they ripped it off causing slight buckles in the quarter. Not to worry this is a very easy fix and can mostly be PDRed!

I originally had purchased Euro S bumpers and have since acquired a pair of Ruf bumpers. The rear is complete with the center outlet for the exhaust. While some fabrication will be required to make it work Karl and I thought this touch would be nice and well worth the effort.

The wheels were originally SSRs and as you can imagine were never to be seen again. The original wheels were purchased with the car but I am not much about anything original. The first 993TT I had RUF wheels fitted to it. Heavy but stable and a very nice ride I enjoyed them. I transferred these to my 01 996TT then finally sold them off to a friend of ours. Since then he had decided that he wanted to sell them, I was first in line. I purchased them and sent them out to be powder coated artic silver. This should prove to be very durable in comparison to paint.

The interior looks worse than it is. In the box of goodies from LA Porsche there should be the airbag covers and the side quarter panels. The original front and rear seats came with the car since they were removed to install a bar and GT3 seats which ARE gone.

Sadly it was a week of craziness and the bumpers came in on Tues and it was yesterday that I finally opened them up. The box of goodies from Sara and Todd I have yet to unpack!

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Fitted with the front S Euro bumper.

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This should have gotten the stupid of the year award. Too bad the bag didn’t go off in their face!

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They couldn’t get the roll bar out that bolts in to the seat belt holes without doing this!! Idiots.

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Bilsteins and Monoballs installed.

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Motor as it sits. I had purhased a NA intake and was going to change a few things to make it a TT setup. That has since changed of course.

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Classic wheels, in a world of bling, something with class.

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Front RUF bumper. Needs some tweaking but we are up to the task!

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Damn inspector again. Making sure the bumpers are in fact not like the old ones. She approves!

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911, 911 Porsche, 993TT, 997TT, engine builder, engine rebuild, Forced induction, supercharger, turbo, turbo Porsche, Uncategorized

To turbo, or supercharge that is the question

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Which came first the chicken or the egg? Which is better the Turbocharger or the Supercharger? They both are very similar. The mechanics of these systems is where the difference is found. They both offer their own advantages and disadvantages but it depends on you, the driver.

So what’s the difference?

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The Turbo-charger uses exhaust gases to drive it and the supercharger uses a belt that runs off the crank shaft to drive it. They both increase the speed of a car significantly. I spent many months researching this topic. The similarities and differences are stunning. These performance parts force the novice mechanic to graduate to the next level of planning and paying for that matter. These systems are not cheap. But for those who enjoy racing down the ¼ mile drag strip at top speed. This may be for you.

Similarities

Both superchargers and turbochargers are forced induction systems and thus have the same objective – to compress air and force more air into the engine’s combustion chamber. The benefit of forcing more air into the combustion chambers is that it allows your engine to burn more fuel per power stroke. Using an internal combustion engine, burning more fuel means that you convert more fuel into energy and power. For this reason, supercharged and turbocharged engines normally produce 40% to 100%%2B more power than normally aspirated engines.

How They Work

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A supercharger is mounted to the engine and is driven by a pulley that is inline with the crank (or accessory) belt. Thus, the supercharger robs horsepower from the engine in order to multiply horsepower, giving it back to the engine. Kind of in a circular fashion. (For example, I give you 5 dollars and you give me back 25 dollars) this is how the power multiplies within the supercharger. Air is drawn into the supercharger and compressed by either an impeller (centrifugal-style supercharger), twin rotating screws (screw-type supercharger), or counter-rotating rotors (roots-type supercharger). The air is then discharged into the engine’s intake. Faster crank speed (more engine rpm) spins the supercharger faster and allows the supercharger to produce more boost (normally 6 to 9 psi for a street vehicle). Typical peak operating speeds for a supercharger are around 15,000 rpm (screw-type and roots style superchargers) and 40,000 rpm (centrifugal-style superchargers). Thus a supercharger is easier to tune because the speed of the supercharger directly relates to the speed of the crankshaft.A turbocharger operates in much the same way as a centrifugal (internal impeller) supercharger, except it is not driven by pulleys and belts attached to the engine’s crank. A turbo is instead driven by exhaust gasses that have been expelled by the engine and are traveling through the exhaust manifold. The exhaust gas flows through one half of the turbocharger’s turbine, which drives the impeller that compresses the air. Typical operating speeds of a turbocharger are between 70,000 and 160,000 rpm. 

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Let’s look at the 2 side by sideTurbocharger vs. Supercharger Cost

The cost of supercharger and a turbocharger system is basically the same. However, if you are deciding which to use. First, determine your mechanical ability and the accessibility of special pipe benders and welders. If you don’t have access to these tools then a supercharger will be more reasonable because you will likely be able to do all of the work saving on the cost of labor. Turbochargers require special pipe benders because of the extensive exhaust set up.

Lag vs NO Lag

The supercharger can very easily boast that the biggest advantage it has over the turbo charger is NO LAG. Turbochargers are driven by exhaust gas. The turbocharger’s turbine spools up first before it even begins to turn the compressor’s impeller. The result is what we call “lag time”. This is the time needed for the turbine to reach its full throttle from an intermediate rotational speed state. During this lag time, the turbocharger is creating little to no boost, which means little to no power gains during this time. It is common knowledge that smaller turbochargers spool up quicker, which reduces some of the lag. Turbochargers use what is called a “waste-gate”. The waste-gate is a valve that allows exhaust to bypass the turbine blades. The waste-gate senses boost pressure, if it gets too high, it could be an indicator that the turbine is spinning too quickly. In this situation the waste-gate avoids some of the exhaust around the turbine blades, allowing the blades to slow. Therefore, a waste-gate allows a smaller turbocharger to eliminate some of the lag time while preventing it from spinning too quickly at high engine speeds. A waste-gate is a crucial part of the Turbocharger.On the other hand, a Supercharger is connected directly to the crank, so there is “NO LAG”. Superchargers are able to produce boost at a very low revolutions per minute (RPM).

Which is more economical?

Some say the turbocharger is more economical. It all depends on your level of mechanical ability and your ability to access good quality welders and pipe benders. Some feel that the turbocharger is more economical to operate because it is driven primarily by potential energy in the exhaust gasses. The gas would normally be lost out of your exhaust pipes. However, the supercharger draws power from the crank, which is normally used to turn the wheels. One positive, is that the turbocharger’s impeller is powered only under boost conditions, so there is less internal drag when the impeller is not spinning. The turbocharger does create additional exhaust backpressure and exhaust flow interruption which can be viewed as less than positive. If you are looking to save money and have the tools handy that you will need to complete this installation successfully then this may be for you

.Very Hot vs Not so Hot

The turbocharger is mounted to the exhaust manifold which is extremely hot. Turbocharger boost may experience additional heating through the turbocharger’s hot casing. Hot air expands which is the exact opposite of what happens in a turbocharger or supercharger, therefore an intercooler becomes necessary on almost all turbocharged applications to cool the air charge before it is released into the engine. Remember, when we discussed the special pipe benders. This is where the complexity of the installation can be a challenge. A centrifugal supercharger on the other hand creates a cooler air discharge, so an intercooler is often not necessary at boost levels below 10psi. However, some superchargers (especially roots-type superchargers) create hotter discharge temperatures, which also make an intercooler necessary even on fairly low-boost applications.

Surge

Turbochargers spool up before its boost is delivered to the engine, when this happens there is a surge of power that is immediately delivered. This happens when the waste-gate opens at approximately (2500-3000 rpm). The surge can cause extreme damage to the engine and drivetrain, and make the vehicle difficult to drive or lose traction. Superchargers also experience surge which is why they have a blow-off valve to release the excess pressure during deceleration. (All superchargers should come with this blow-off valve as an accessory)

Exhaust Back Pressure

Remember the supercharger is powered by the crank, thus there is no need to deal with the exhaust gas interruption created by inserting a turbocharger turbine into the exhaust flow. The supercharger creates no additional exhaust back pressure. The amount of power that is lost by a turbocharger’s turbine reduces it’s overall efficiency.

How Loud is it?

The turbocharger is generally quieter than the supercharger. Because the turbo’s turbine is in the exhaust, the turbo can substantially reduce exhaust noise, making the engine run quieter. Some centrifugal superchargers are known to be noisy and may sound like a bird chirp at idle, which annoys some drivers.

Dependability

Normally superchargers are more reliable than a turbocharger. When the engine is turned off (i.e. the turbo is shut off), residual oil inside the turbo’s bearings can be baked by stored engine heat. This, combined with the turbo’s extremely high rpms (up to 150,000rpm) can cause problems with the turbo’s internal bearings and can shorten the life of the turbocharger. In addition, many turbos require aftermarket exhaust manifolds, which are often far less reliable than stock manifolds.

Ease of Installation

Superchargers are substantially easier to install than a turbochargers because they have far fewer components and simpler devices. Turbochargers are complex and require manifold and exhaust modifications, intercoolers, extra oil lines, etc. – most of which is not needed with most superchargers. A novice home mechanic can easily install most supercharger systems, while a turbo installation should be left to a turbo expert.

Peak Power

Turbochargers are known for their unique ability to spin to incredibly high rpms and make outrages peak boost figures (25psi). While operating a turbocharger at very high levels of boost requires major modifications to the rest of the engine, the turbo is capable of producing more peak power than superchargers.

Tuning

Turbochargers, because they are so complex and rely on exhaust pressure, are notoriously difficult to tune. Superchargers, on the other hand, require few fuel and ignition upgrades and normally require little or no engine tuning.