Stephan's SLC Build Log

[Stephan E.]

...and back at it...

At some point during my travels I started to think about how loud the initially planned side exhaust would be with an engine pushing out that much HP at that RPM level. For the sake of my hearing I tossed the entire idea, decided on a rear exhaust solution which involved the relocation of the engine management electronics which will be covered in a separate post. Here are my first attempts to make an exhaust fit where the word "tight" entered a new dimension. In addition, Mercury Racing left me a little present with their home made exhaust manifold bolt pattern. Since there are no matching gaskets on the market I had to made them too. This series of pictures starts with the modifications to the manifold and gaskets...

 

[Stephan E.]

Here is a series of pictures of the tacked exhaust collectors and first test fitment. This engine is a few inches wider than a LS series and the manifolds sitting over the frame rails. I maxed out at about 10 degree tilt due to spacing issues with the collector flange bolts.

 

[Stephan E.]

Preparing for ceramic coating. Here you can see how I am removing the weld splatter and hand buff with fine Scotchbrite before throwing the manifolds into a ceramic ball media vibrator bowl. The coated manifolds in Chrome effect and the collectors in matte finish since there are being wrapped too to minimize heat radiaton. I had to find a new routing for the shifter cables due to heat exposure. The cylinder heads are too wide to allow for the traditional routing.

 

[Joel K]

Man, that is a tight fit. Your work is so nice, the exhaust came out great Stephan. I agree with the side exhaust being just too loud, the side exhaust would work at Le Mans but not Yardley! Nice job!

 

[Stephan E.]

Thanks Joel,

And here is the drivers side setup. A little bit more clearance on the upright frame rail due to the staggered cylinder banks.

 

[Stephan E.]

I purchased these really nice mufflers in brushed stainless and added the V-bands. The muffler bodies are only 3.5" OD and fit through the openings provided without eliminating any supports. I am still mocking up the connections to determine the final locations. I somewhat like the straight out version with the mufflers exiting the rear but will play around a bit.

 

[Stephan E.]

In the meantime I was able to finish the hydraulic connection to the transaxle. Like everything else using -AN fittings with stainless tubing. The banjo fitting is M 12 x 1.5 to -3AN from Summit.

 

[Ian Anderson]

In the meantime I was able to finish the hydraulic connection to the transaxle. Like everything else using -AN fittings with stainless tubing. The banjo fitting is M 12 x 1.5 to -3AN from Summit.

I would have thought you would need some flex hose in there to stop cracking of the hard lines. The whole lot will move under acceleration and braking.

Ian

 

[Neil]

Those hard lines should be OK if you add support clamps to minimize long unsupported runs of tubing. The vibration will eventually crack the tubing as it is now.

 

[Stephan E.]

Slowly but surely I am approaching the final stages of the exhaust system.

 

[Stephan E.]

Those hard lines should be OK if you add support clamps to minimize long unsupported runs of tubing. The vibration will eventually crack the tubing as it is now.

Word taken. Along the way I will replace the rigid line with a braided flex hose.

 

[John]

Nice tig work on that stainless.

 

[Roger Reid]

Yes, nice welds.

 

[Stephan E.]

Since the exhaust is more or less done I returned back to the coolant system which was neglected due to other priorities. The initial layout was altered to what you can see now. Also the coolant flow is now going with the hot side into the high port on the radiator and the return is on the low end which required to cross under the engine. The direction of flow can be inverted if required by changing two connections. I added ports for drainage and filling/ burping at the highest and lowest points in the system which will be blanked off. In addition the NPT threads for the temperature sensors. The forward and return lines to the heater core are connected directly to the pumps positive and negative pressures sides as per manufacturers specifications. The coolant expansion tank went up onto the bulk head. Not my absolute favorite position but I have to use the room available. I gave the tubing a brushed finish.

This was fun to build and I can reach all components relatively easy.

 

[Joel K]

Nice work Stephan, getting closer and closer to go-cart. Looking forward to seeing all the details in person.

 

[Stephan E.]

Nice work Stephan, getting close and close to go-cart. Looking forward to seeing all the details in person.

Thank you Joel,

I don't feel like I am close to go-cart mode. The oil cooling system is on the radar and the electrical work needs finishing.

Happy Holidays

 

[Stephan E.]

Finally an update. The engine and transaxle oil cooling system took me some time to come up with. The usual side mount was not an option. Since I do rely on cold and dense air due to having an naturally aspirated engine, the oil cooler placement became kind of challenging. I decided to dedicate the two air intakes to the air filters and place the coolers where there are in a nice air stream not becoming a heat source. I also had to consider some BTUs I have to get rid of and ended up with two 19 row coolers adding up to 38 rows total just for the engine. The transaxle cooler is mounted piggyback on the transaxle with a fan and thermostat. The two engine coolers are sitting in lined chassis on the diffuser and can slide out without disconnecting the pressure lines. To make sure the pressure lines and cooler can be properly filled and vented I added the Peterson oil filter/primer station. This will also help after long resting times to give the engine a pre-lube without starting. All you need is a power drill. There is a dry sump pump added to the primer station which sucks from the oil pan or dry sump tank. The pump can generate 20 PSI. The wing uprights were chopped 100mm and the transaxle cutouts shaped symmetrical, everything was primed and painted.

 

[Ken Roberts]

Just a heads up Stephan. I noticed your oxygen sensor bungs welded to the pipes at the bottom (6 o'clock position). The sensors should never point up. They will have a short life due to the condensation running into them upon warm up. Bungs should be located so the sensor is horizontal or facing down. (Ideally between 10, 12 and 2 o'clock position).

 

[Stephan E.]

more pictures

Just a heads up Stephan. I noticed your oxygen sensor bungs welded to the pipes at the bottom (6 o'clock position). The sensors should never point up. They will have a short life due to the condensation running into them upon warm up. Bungs should be located so the sensor is horizontal or facing down. (Ideally between 10, 12 and 2 o'clock position).

Hi Ken,

Thanks for the update. The bungs are actually in a 45 Degree position when installed due to the angle the collector is welded. There is absolutely no room to put them anywhere else. This engine does not use any oxygen sensors and I added the bungs just in case I would ever retune the engine.

 

[Stephan E.]

More pictures on the oil cooling subject.