Showing posts with label Engine. Show all posts
Showing posts with label Engine. Show all posts

Thursday 29 December 2022

Engine & Gearbox Installation - Part 2 - Flywheel and Clutch

With the engine removed from its stand and hanging from an engine hoist, the next job was to install the flywheel and clutch.

Due to the engine sitting for some time, some light surface rust had appeared on the rear crankshaft flange.  I cleaned this up using a Scotch-Brite pad and gave the flywheel mounting flange a good clean with some brake cleaner, including the recess where the pilot bearing will be installed.

The directions for the ARP flywheel fixing bolts that came with my transmission installation kit specified the use of the included ARP lube under the head of the bolts with some Loctite 242 on the threads.

Loctite 242 (or Loctite 'Blue') is a medium-strength thread-locking compound.  There is an 'improved' product available, Loctite 243 (obviously), which has an improved oil tolerance and so doesn't require bolts to be scrupulously clean to be effective.  

Installation of the flywheel was straightforward; I applied a smear of the ARP lube under the bolt heads and on the top half of the thread plus a drop or two of Loctite 243 on the end of the thread.  I held the flywheel up against the crank mounting flange, screwed all the bolts in hand tight and then torqued them up in stages and in an alternating pattern to 85ft-lbs / 115Nm.

(The ARP flywheel bolts have a 12-point head.  While I could tighten the bolts up reasonably tight with a normal 14mm socket, when trying to torque them up to the final specification, the 14mm socket did slip on the bolt heads.  So rather annoyingly I had to order some 12-point sockets, which meant that I had to remove all the bolts and clean them up while waiting for the new sockets to arrive; had I left them in place, the thread lock would have cured and then when torquing the bolts that would likely have broken the bond rendering the thread locker useless).

Flywheel installed at 2nd attempt

I then tapped the pilot bearing into the recess in the crankshaft, using a socket as a suitable drift, until the front face was just flush with the front of the recess.  The pilot bearing is a roller-type bearing and was already greased.  I didn't add any extra grease to avoid excess lubricant being flung around in the vicinity of the clutch plates.

Pilot Bearing in place

I then gave the flywheel a good wipe down with brake cleaner and several paper towels to remove any traces of oil that were on the flywheel from the supplier (and my greasy mitts!) to protect it from rusting.  Once I had done that, I did it again, just to be sure!

The clutch installation was reasonably straightforward despite my opting for the twin-disc clutch setup.  I offered up the first clutch disc to the flywheel using the normal plastic clutch alignment tool that seems to come with all clutches.  I then needed to secure the adaptor which holds the floater plate for the twin-disc set up to the flywheel.  I put a couple of drops of blue Loctite on the securing bolts and torqued them to 25ft-lbs / 34Nm as per the instructions.  At this point, the bottom clutch disc can still spin freely between the flywheel and the floater plate.

Clutch discs have idiot-proof markings!

First (bottom) disc in place

Adaptor ring and floater plate installed

I then installed the second (top) clutch disc again paying heed to the orientation markings handily written on the disc.  This requires the removal of the clutch alignment tool so that it can be inserted through the top disc and then reinserted through the bottom disc.  So of course when it is removed the bottom disc drops and it was a bit fiddly to try and lift it back up and realign the plate so that the nose of the clutch alignment tool could slide fully into the pilot bearing and hold both plates in the correct place.  With that done I could place the pressure plate onto the mounting studs on the adaptor plate, taking care that the original assembly marks lined up, and secure the pressure plate with the mounting washers, spring washers and nuts.  The instructions are very clear not to use Loctite on these mounting nuts, so I didn't, and I followed instructions for torquing down the pressure plate nuts in an alternating pattern to 25ft-lbs / 34Nm and then 35ft-lbs / 47.5Nm.

Just to note as soon as the nuts on the pressure plate are tightened up even hand-tight, both clutch plates become fixed and will no longer move.  If the clutch alignment tool is not perfectly centralised and aligned, and the pressure plate nuts tightened then the plates might be slightly out of alignment which makes removal of the alignment tool incredibly difficult (but which also suggests that getting the gearbox input shaft back through the plates will be equally difficult).  I went through the process of tightening each of the pressure plate nuts by hand, around half a turn at a time, in an alternating pattern, while constantly moving the alignment tool in and out slightly to ensure that once the bolts were nipped down sufficiently and the plates fixed, that I could still slide the alignment tool in and out smoothly.

Pressure plate installed - looks too good to cover up!

The next step will be to join the gearbox and bellhousing to the engine.

Saturday 5 November 2022

Engine & Gearbox Installation - Part 1

My engine has been sitting in the corner of the garage on an engine stand and acting as a giant dust magnet since I collected it back in 2020.  Exciting times are ahead as I have reached the stage where I can seriously contemplate being able to install the engine and gearbox into the chassis.

There were a couple of bits that I was able to do before having to remove the engine from the stand to allow the gearbox to be fitted up.

First was to install a thermostatic take-off plate for the oil cooler.  I purchased a Derale LS Engine Oil Cooler Adaptor from Summit Racing.  This is a thermostatically controlled adaptor which allows the oil to bypass the oil cooler until the oil temperature reaches 180 degrees Fahrenheit.  It also includes two 1/8" NPT ports which can be used for oil temperature and pressure sensors for dashboard instruments.

Oil Cooler Adaptor 

The adaptor is installed by removing the cover on the side of the LS engine block above the oil filter.  There are two oil galleries behind this and the cover simply provides continuity of flow between the two.  

Location of the original cover plate above the oil filter

The cover simply provides a channel to connect the two oil galleries


As I do not have my dash instruments yet and therefore do not know the necessary senders required I sealed the two NPT ports in the adaptor with plugs which come supplied with the adaptor.  I used PTFE tape on the plugs just in case I end up running the engine without having installed the sensors.  

The adaptor also requires two AN adaptors to be installed to which the oil cooler lines can be connected.  The two ports on the top of the adaptor are -10 ORB fittings.  This, as I discovered, means that they are a -10 AN thread (7/8" UNF) while ORB stands for O-Ring Boss, meaning they need to be installed with an O-Ring seal.

I purchased two -12 AN to -10 ORB adaptors from Torques Products Ltd.  I lubricated the O-rings with some engine oil prior to installation and tightened both adaptors into the top ports.  

-12 AN to -10 ORB Adaptor

The adaptor plate itself also comes with two O-rings that need to be installed into grooves on the rear of the adaptor (I didn't lubricate these) before the adaptor plate is bolted into place with two M6 bolts which were torqued to 120inch lbf.  Note the inch rather than foot torque specification!! This equates to a mere 10ft lbf / 13.6 Nm so I could dig out my smaller torque wrench for this job!

O-rings installed on the rear of the adaptor

Oil Cooler Adaptor bolted in place

I also took the opportunity while the engine was on the stand to install the starter motor.  This will allow me to check the clearances between the starter pinion gear and the flywheel before the bellhousing is installed and makes that task pretty much impossible.

I was supplied a standard GM starter motor with my engine but I elected to actually install a Proform high-torque gear reduction starter motor.  This type of starter has a lower electrical power demand but still produces enough torque to spin over higher-compression engines.  The Proform starter also can be "clocked" in three different rotational positions to allow more clearance of the solenoid from exhaust pipes or other components if necessary.

Standard starter (top) vs High Torque starter

The three bolt positions on right allow starter body to be rotated relative to mounting plate

Installation of the starter was straightforward being held in place by just two bolts.  I haven't torqued these up to final specification at present just in case starter needs to be removed to add shims to get the correct clearances to the flywheel.

Starter motor in place

The last job before lifting the engine off the stand was to bolt on the engine mounting plates.  These were fixed in place with 4No. M10x25 bolts and M10 washers each side.  For added peace of mind I put a drop of Loctite 271 on each of the bolts before installation.

Engine mounting plate in place

With those jobs done its time to get the engine crane out and lift the engine off the stand to allow flywheel and clutch to be installed.





Tuesday 25 May 2021

Gearbox Part 1 - Now for a Live Transmission from our on the spot reporter....

For those of you who have been following this blog, you will recall that my original intention was to use an LS3 engine with a Tremec TKO600 gearbox.  The TKO600 is a 5 speed transmission capable of handling up to 600 lb-ft of torque.

So despite my change of plans on the engine front, with my Kyle Rushall-built LS7 chucking out a whopping 603 lb-ft of torque, the TKO600 unit should still have sufficient capacity (let's face it, the tyres will probably lose traction before the gearbox implodes....).  There was just one small problem....

Having left my decision to order the said transmission from Roadcraft UK to late Spring 2020, the ongoing COVID pandemic was resulting in a shortage of deliveries from the US of A.  There were no TKO600s to buy!

Plan A - Tremec TKO600 5-speed Transmission (Photo courtesy of Tremec)

Then in Autumn 2020 Tremec made the decision to stop making the TKO gearboxes, replacing them with its new 5-speed TKX transmission.  This is basically an improved TKO, with improved durability for high RPM shifts, still with a torque capacity of 600 lb-ft, but intended as an aftermarket replacement transmission that can be fitted without significant modification to chassis / floorpans.  Small problem though, still no deliveries from the States and Brian at Roadcraft UK wasn't even sure when deliveries of the new transmission might commence.

Some of the bits that make the TKX improved...but still can't get one! (Photo courtesy of Tremec)

Brian contacted me in March 2021 and said that he had a consignment of Tremec T56 Magnum transmissions on the way and due for arrival shortly.  The Magnum is the top of the line of the Tremec aftermarket transmissions.  It is a 6 speed transmission, capable of handling 700 lb-ft of torque, and is essentially an aftermarket version of the TR6060 transmission which is factory fitted to recent cars such as the Dodge Viper, Dodge Challenger and Chevrolet Camaro.  Its basically bulletproof!

T56 Magnum Transmission (Photo courtesy of Tremec)

My only concern with using the Magnum 'box is that it is slightly longer than then TKO gearboxes, which results in a very short prop shaft and, due to the slight misalignment between the output shaft of the gearbox and the input shaft on the rear differential, ends up with the prop shaft being at a significant angle to the line of the gearbox and differential; I was worried that the angle would put undue pressure on the universal joints, especially given the power output of the engine.  

Resulting prop shaft angle due to short distance between diff and end of T56 transmission (photo courtesy of Mark Clayton's build blog)

However, a quick chat with Jon at AK Sportscars reassured me that they install a large number of Magnum boxes in their factory builds and demo cars and do not see the prop alignment as an issue.

So decision made, a deposit was paid to Brian at Roadcraft UK, and I could put my feet up and wait for my gearbox to arrive!




Sunday 19 July 2020

Engine Update

Back in my January 2020 update post, I dropped some hints about my change in engine choice.  427 cubic inch, titanium rods and, the need for a dry-sump tank...

So if you hadn't already guessed, I am now planning on installing an LS7 engine instead of the LS3.  My engine builder, Kyle, made me an offer I literally couldn't refuse.  He also persuaded me to consider dry-sumping the motor to eek out a few extra horsepowers - hence the need to try and find a location in the confines of the AK for a remote oil tank.

So the revised engine specification looks a bit like this
  • LS7 Pistons - Mahle PowerPak Forged 4032 Alloy for low expansion with Grafal anti-friction skirt coating - modified wrist pins - hot washed and checked
  • Mahle High-Performance Piston Rings
  • Compression Ration approx 11.3:1
  • Competition Cams Camshaft (guaranteed to pass IVA / MOT)
  • Competition Cams reduced travel Hydraulic Lifters
  • Competition Cams Rocker Trunnion Upgrade (with needle roller bearings)
  • LS7 Titanium Conrods
  • ARP High-Performance Big End Bolts
  • Clevite H-Series Big End and Mains Bearings - 
  • MLS Head Gaskets
  • Double Valve Springs
  • Uprated Water Pump
  • New Front Damper
  • LS7 Sump Pan with adaptor for -12 oil lines to remote tank
  • New LS7 Intake with 42 lb per hour Injectors
  • One Piece Manley Pushrods
  • New Gaskets
  • New Sensors
  • New Oil Seals
  • Fly-by-Wire Throttle Body
  • Custom Corvette Front End (Power Steering Pump, Alternator, Idler and Custom Tensioner)
  • Canems ECU and Wiring Loom modified to include immobiliser 
  • Dyno Run and Set-up

Kyle started pulling together all the parts for the engine earlier this year but the Covid-19 pandemic caused a few delays with some of the parts coming from the States so final assembly did not begin until mid-June

LS7 Bare Aluminium Block with pressed in Steel Cylinder Liners

Cam installed and upper main bearings in place - note dowels to assist location of end caps

Forged Steel Crankshaft 2.559in dia Mains / 2.100in dia Rod Journals

Reluctor Wheel (24X) welded to Crankshaft

Pistons and Rods ready for assembly

Piston Ring Gapping

Short Block Assembly complete

Cylinder Heads - CNC Ported / 70cc Chambers - 2.205in dia Titanium Intake Valves & 1.610 in dia S/Steel Sodium Filled Exhaust Valves

Uprated Valvetrain

Fly-by-Wire Throttle Body

Sump Adaptor to connect to remote Oil Tank

Assembly almost complete - looking like an engine!

The LS7 was the largest displacement engine in the LS engine series.  It was based on the C5-R engine used in the Le Mans racing Corvettes so is purpose-built for high performance.  It found its way into a number of GM cars between 2006 and 2015 most notably the Corvette Z06.

The stock LS7 produced a respectable 505bhp at 6300rpm and 470lbft torque at 4800rpm.  Kyle built the LS7 for Apple, the AK demonstrator, which put out around 630bhp and a shade under 600lbft torque, some serious gains over stock, and I would have been happy with similar numbers from my engine.

Kyle had the engine hooked up to his dyno at the beginning of July and spent a day checking over for leaks, before a session at fast idle to run in / bed in the engine.  The plan was for Dave from Canems to come and assist with the set-up of the ECU before carrying out the power pulls proper.

On the dyno and ready to rumble...



About mid-day on the day that Kyle was hoping to do the power pulls, I got a phone call.  "Are you sitting down?" he said.  So down I sat, thinking the engine had blown up on the dyno or some other equally catastrophic scenario.  Turned out the numbers on this beast exceeded even Kyle's expectations; 659bhp at 6300rpm and 603lbft at 4900rpm! He was over the moon and so was I!

Dyno output...

...peaking at 658.6bhp and 602.9lbft torque!

Torque exceeds 500lbft from around 3000rpm!


While the engine was still on the dyno I took the opportunity to pop up to Kyle's workshop and check it out in action.  It also gave me the chance to familiarise myself with all the various connections from the ECU to the engine sensors and to get some guidance from Kyle for when I come to start up the engine myself.




The video above of the outside of the dyno room just does not convey the power of this engine - it was like a Force 8 gale blowing out of the exhaust pipes and the whole ground was shaking.  Absolutely awesome piece of kit and I would recommend Kyle without a doubt to anybody wanting to get some serious bang for their buck on the engine front.

I should be picking engine up in a couple of weeks time so I guess I'd better crack on with getting the rolling chassis completed!!



Tuesday 16 July 2019

Engine Ordered!

So it appears I have just put down a deposit for my engine!


My plan for the engine is to use a Chevrolet LS3 engine with a Tremec TKO600 transmission. 


My original thought was to buy the engine and gearbox as a complete package from Brian at Roadcraft UK Ltd.  Brian had given me a quote based on the 430hp version of the GM LS3 Crate Engine with all ancillaries and ECU.

I would have preferred the 525hp version of the LS3 Crate Engine, but from reading on the various internet forums it seems there is no chance of this engine passing the IVA emissions test.


At the end of last year another AK Cobra Builder, Barry Boughton, had contacted me after reading my blog.  He recommended the name of a guy, Kyle Rushall, who had built his LS7 engine and also apparently built the engines for Apple and Rufus, the AK Demonstrator vehicles.  I've been in Apple and I can testify to the power the engine in that beast puts out!


Turns out that Kyle used to work at Tim Adams Racing Engines and has built quite a few engines for the Cobra community.  He is now working on his own and building engines for the GT and Drift scene amongst others.  


I made a mental note to drop him a line, but figured that getting a bespoke engine built was always going to be more expensive than buying a crate engine package and never really got round to it. Besides I was planning on spending the rest of 2019 getting the rolling chassis completed and didn't think I would be in a position to need the engine/transmission until early 2020 at best.


Anyway a few weeks ago I saw an advert on Fleabay for an LS7 engine; the price was out of my range but the seller was also offering LS3 engines.  I sent a message asking for prices and it turned out the seller was none other than Kyle Rushall himself!  


He suggested I give him a call to discuss options, which I did and we had a good chat through things.  Turns out he has built a few LS3 engines for Cobra builders now; the last one made over 560hp and passed the IVA test! Not only that but the price he quoted was not a million miles away from what Roadcraft UK was quoting.


Unfortunately, Kyle only has two LS3 cores left and is not expecting to get any more until late 2020.  So after some brief (?!) negotiating with my better half, I have altered by budget plans and put down a deposit to secure one of the remaining cores.
 
The specification for my AK LS3 550 includes

 
  • LS3 Pistons - hot washed and checked
  • Mahle High Performance Piston Rings
  • Custom Camshaft (not too aggressive grind - but guaranteed to pass IVA / MOT)
  • Competition Cams reduced travel Hydraulic Lifters
  • Competition Cams Rocker Trunnion Upgrade (with needle roller bearings)
  • LS3 Conrods
  • ARP High Performance Big End Bolts
  • Clevite Big End Bearings
  • Clevite Mains Bearings
  • MLS Head Gaskets
  • Double Valve Springs
  • Melling Oil Pump
  • Uprated Water Pump
  • New Front Damper
  • New F-body Oil Pan (to fit AK Chassis)
  • New LS3 Intake with 42 lb per hour Injectors
  • One Piece Manley Pushrods
  • New Gaskets
  • New Sensors
  • New Oil Seals
  • Fly-by-Wire Throttle Body
  • Custom Corvette Front End (Power Steering Pump, Alternator, Idler and Custom Tensioner)
  • Canems ECU and Wiring Loom
  • Dyno Run and Set-up
 
Kyle is a busy man and engine won't be ready until later this year, which is fine for me as I still have a way to go to get rolling chassis completed.

I'll have one of those please! (Photo courtesy of Kyle Rushall)