I have spent a lot of hours on this site over the years. My father has an 07 300C SRT8 and thanks to this site we've made it into a pretty tough sleeper. Lately we've been working on my Jeep and even though this is a forum dedicated to the LX platform., I thought I'd share part of our build here.
I'm 40 and my dad is now semi-retired. He works from home and we built his garage so we could spend time in there doing things like this.
This project started over a year ago. Dozens of phone calls to several vendors and lots and lots of research led me to Dave Weber at Modern Muscle PerformanceGroup. I've worked with and bought several things from most all of the vendors in the Hemi community and Dave was the best fit for me. Our goal is a street oriented, driver friendly, powerful machine that can launch hard on the street. We are not interested in any track records. After a lot of discussions, Dave, my dad, and I decided on a 6.1L based stroker with Thitek heads. The actual pistons and pins Dave had in mind didn't exist at this time other than in his head. We had nothing but time and were in no hurry for the engine so we gave him the go ahead to start things rolling. He worked with Mahle over the next couple months and the pistons came to fruition. Dave also worked with ATI to get me a 17% overdrive damper that was lighter weight than the norm.
It was apparent from the beginning that the limiting factor of the engine would be the Magnuson sitting on top. Initially, the plan was to build a bottom end that could support the Maggie maxed out but as things escalated, as things often do, the Maggie became the weak link. Whipple had a new 2.9L twin screw out that would be a better fit but they didn't have one for the WK1 engine configuration. Dave talked us into a Whipple and challenged us to make it work. So that's what we did. We pulled the Maggie off and sold it. Put the Whipple on and redid the fuel system completely for the future goals.
Dave finished up the engine and we received it late in June. We've been sitting on the engine waiting for the winter when we can take the Jeep down for a few months. We've used that time to fine tune the Jeep and get it as ready as possible for the new power plant. I've had a lot of fun driving it and the weather has been unseasonably awesome for the last month so I've been taking advantage of that and been enjoying the Jeep. I expect to take a couple months to tear down the engine and build it back up. I want to redo some custom brackets I've made and that will be time consuming but so much easier with the engine out of the way. Same with the wiring. The stock wiring harness is going on 10 years old and needs a lot of tlc.
I have the week off so I went over to the garage to work on the Jeep. Little did I know, we were going to work on suspension parts all day. Yesterday we worked on putting in the front differential bushing and looked over a few different things. I pointed out some a-arm bushing that looked a little degraded to my pops and we assessed what it would take to replace them. There is this clevis bolt that is infamous on the Jeeps for being stubborn to get out. It rusts and welds itself to a metal sleeve inside a rubber bushing. Impact wrenches do nothing because the rubber absorbs the impact. Breaker bars just twist the rubber. We spent an entire day working on these bolts (one on each side) a year ago when we put in lowering springs and new struts. We failed at getting them out and ended up replacing the struts with the clevis still attached. We decided that we would leave the suspension upgrades and replacements for another time so I kept on cleaning. Apparently, my dad re-decided to visit the suspension again last night.
After that clevis bolt kicked our butts most of the day, it's now in three pieces and the lower a-arm is out.
I finally refurbished the wiring harness. I was putting this task off as long as possible because I knew it wasn't going to be much fun. It's 10 years old. It was covered in grease and grim. It had worn and weathered pretty bad in a few places and no less than two of the connectors needed repaired or replaced. Most of the electric tape was falling off. I looked into replacing it with a new one but the price was cost prohibitive.
I bought some new connectors and wire wrap sheathing. I wore latex gloves whenever I handled the wiring as I was cleaning it because it was that nasty dirty.
To ease the pain, I set up shop with everything I needed in front of the 70" tv. It took me eight hours over a two day period to finish it.
Here's a good shot of what I was working with.
Every time I stepped away the dog would take the seat.
Hard to tell from a distance but it is almost like new.
My dad cleaned up the drive shafts. The front shaft was nothing but surface rust. I should have taken a before picture.
Also just got new a-arms in today. They came bare metal so my dad painted them.
Received new engine mounts.
And we also refurbished a whole bunch of bolts. My dad spent a couple hours in front of the wire wheel on the bench grinder (a nice 8" variable speed unit I bought him). Then we painted the heads.
I also wanted to paint the 90mm throttle body. It was a cast version and while it performs well, it's nothing special to look at. It was really rough so I smoothed out some areas and then painted it with a textured black in an effort for it to match the black whipple.
We kind of went wild with the suspension. Now was as good a time as any to replace a few of the worn bushings so we replaced them all. The brakes, struts, and springs were all replaced or redone last year.
Kevin you are an animal bro, your build since the day I borrowed you my crank pinning kit has been my favorite build!
Keep up the awesome work! :thumbs_u:
Kevin I must say your attention to detail is amazing, dare I say borderline obessive compulsive with a little psychotic sprinkled in. I personally could never produce this type of patience and attention that is required but I can truly respect it. Awesome build you and your dad got going on there. Look forward to more postings.
When I got the short block, it came on an engine cradle for shipping. It was nice enough that we threw some castors on it and used it to store the engine for a few months. We have an engine stand but we like how low this sits and how the engine is supported compared to the engine stand. The cradle has served us well and it was time to modify it a little bit. It worked great for shipping but it was a little crooked, tilted to one side and leaned forward. In general, it just wasn't square.
So my dad and I cut it up and added some additional bracing.
Some of the tools we have hidden around the garage.
Squared up and test fitted.
Then I welded it back up.
Painted up and ready for the Hemi.
The engine now sits straight and as an added bonus we can hang headers on the engine as well.
We've been doing some research on 8 rib pulley systems. I really want to upgrade but it all hinges on the A/C pulley and water pump pulley which I need help with.
Here's the difference between the idlers.
The 6 rib idlers came with a three step spacer for the pulleys.
If I ever get a chance to run the 8 rib setup, the idlers require 0.130" more on the spacer to make them line up correctly. I had a machinist friend at work turn a couple new spacers for me.
We decided to switch up the head gaskets right before we installed the heads. Dave Weber suggested we use the MLX so we made a trade and he got us a set real quick. I had a couple questions about the heads so I shot Craig at Thitek an email and within minutes he called me on the phone. I called him a couple times later and he was there to answer my every question. I can't thank him enough and express how impressed I am with his service and his product. He was even emailing the next day with additional information. Dave is always a text away and Chris Boegler continues to answer the phone at MMPG despite having caller id and knowing it's me calling.
We re-measured the quench area and piston to deck height to be sure all the numbers added up to what we were going for.
Here's my Pop's gapping the plugs.
The headers installed and torqued on the Thiteks.
ARP studs are in and the heads are torqued down!
Plenty of room. I don't know what everyone always complains about. (That was in sarcastic font.)
The transmission is in. The torque convertor is bolted up. The starter is in. The heads are torqued. The wiring harness is starting to go in.
Still doing little detail projects. I kind of forgot about this piece. It's the torque convertor access cover and when we pulled it out it was covered in grime, grease from the front differential, and road salt. I threw it in a plastic bag with the intent of cleaning it up later. Went to put it on and ended up spending an hour cleaning it up with the wire wheel and painting it.
I decided I better service the transmission before we put the rest of the exhaust in. I wanted to change the transmission fluid out, put in a new filter and install a drain pan with a freakin' plug. And I pulled the valve body out to swap to my other Stage II valve body for some testing. Should be a like for like replacement but my first valve body is proven and I love it. The valve body that came with the transmission is also a stage II but I haven't been completely happy with it yet (maybe the tuning wasn't dialed in correctly yet for it).
Let me tell you a little of what I learned about tensioners over the last couple months.
The stock Mopar tensioner usually does just fine on a naturally aspirated Hemi. When throwing a blower on the thing, the stock tensioner doesn't cut it any more. The Whipple kit and the Magnuson kit both included a Dayco tensioner. I had great luck with the Dayco on both applications. I think the ProCharger kits might even come with a Dayco. There's the Thumper tensioner out there but I've heard mixed reviews on it and it's not cheap. Then there's the GT500 tensioner. Most of the supercharger guys running heavier boost end up with these sooner or later.
I was happy with my Dayco until I tested it's travel with the 17% overdriven damper installed. The Dayco hits the damper before full travel. I did not know of this problem. I called Nate at Demon Performance and he gave me a lesson in broken tensioners. Demon has an adapter plate for the GT500 which clocks it away from the damper to give it proper travel. The GT500 tensioner also allows me to run any size belt I want to (rib wise). Apparently this problem was discovered a few years ago though not many people know about it.
This is not the correct belt size but you can see that the stock or Dayco tensioner will contact the 17% over-drive damper.
Nate sent me a GT500 damper and an adapter plate.
The Dayco and the GT500 tensioners side by side. I was running a procharger pulley on the Dayco.
How the stock and Dayco tensioners naturally mount.
How the GT500 with clocked adapter plate mounts.
GT500 tensioner at full travel.
I did not like the look of the GT500 tensioner so I smoothed out the all the casting marks and raised lettering.
Then I painted it black so it looks a little different even though it will never be seen.
Let me tell you a little of what I learned about tensioners over the last couple months.
The stock Mopar tensioner usually does just fine on a naturally aspirated Hemi. When throwing a blower on the thing, the stock tensioner doesn't cut it any more. The Whipple kit and the Magnuson kit both included a Dayco tensioner. I had great luck with the Dayco on both applications. I think the ProCharger kits might even come with a Dayco. There's the Thumper tensioner out there but I've heard mixed reviews on it and it's not cheap. Then there's the GT500 tensioner. Most of the supercharger guys running heavier boost end up with these sooner or later.
I was happy with my Dayco until I tested it's travel with the 17% overdriven damper installed. The Dayco hits the damper before full travel. I did not know of this problem. I called Nate at Demon Performance and he gave me a lesson in broken tensioners. Demon has an adapter plate for the GT500 which clocks it away from the damper to give it proper travel. The GT500 tensioner also allows me to run any size belt I want to (rib wise). Apparently this problem was discovered a few years ago though not many people know about it.
This is not the correct belt size but you can see that the stock or Dayco tensioner will contact the 17% over-drive damper.
Nate sent me a GT500 damper and an adapter plate.
The Dayco and the GT500 tensioners side by side. I was running a procharger pulley on theDayco.
How the stock and Dayco tensioners naturally mount.
How the GT500 with clocked adapter plate mounts.
GT500 tensioner at full travel.
I did not like the look of the GT500 tensioner so I smoothed out the all the casting marks and raised lettering.
Then I painted it black so it looks a little different even though it will never be seen.
Finished installing the driveshafts and the headers are now connected to the Corsa cat-back. These pipes are huge. The extra O2 bung was installed in the perfect location (lucky guess on my part). There looks to be good clearance everywhere and the only issue I have is they will never be seen. They look awesome.
We put a lot of elbow grease into the Whipple manifold. It's made in two pieces, an upper and lower tub. I posted before the work we did smoothing out the insides and porting the lower tub to the heads. The casting surfaces were rough and the lower tub is not flat and never has been, it's twisted a bit. When laid on a flat surface it rocks and you can tell it is warped. It's not horrible but it would bother some. It's close enough that it flattens out when bolted down to the heads but you can't help wonder what stress it adds to the fasteners. It rocked the same amount on both engines.
The other thing that bothered us about the lower tub was the welded in raised piece and the hump at the front of the lower tub. I sent an email with some pictures to Dennis at Whipple and he got back to me confirming they were there for clearance on other applications. I thought maybe the insert might be some type of blow off relief but that's not the case. They make one tub to fit multiple hemi engines and I imagine there is a couple that have something right where the bulges are. Our 6.1L application doesn't have anything in the way and these are not needed. It may not look like much but once the upper tub with the intercooler is in place, there is not much space inside. The clearances are close and the hump is right in front of the number 1 cylinder.
We decided to take the lower tub to a guy who has done some welding for me in the past as we were in need of someone with more knowledge and experience with cast aluminum manifolds. We were interested in knowing if it could even be welded on anymore after being cut and welded on once at the factory. He gave us a lesson in aluminum and welding and showed us some very neat things he was working on and with. He had a an aluminum intake manifold off some 60's era Corvette that he was repairing just so the owner could have the correct casting marks on the intake when it was being judged. He also has a two and a half inch thick metal flat table that measures 3 feet by 8 feet that was cnc'd flat. Long story short, he talked us into letting him machine out the metal insert and the hump and then welding in a new plate.
It's not easy to see this, but once the upper tub is put in place, the intercooler takes up most of the space. There is almost an inch of clearance to the tub floor when coming straight down out of the intercooler. This is a huge amount compared to the magnuson. But there is only about 0.500" to the sides where the air has to make a couple 90 degree turns to get to the ports. That hump took up all of the space in the front and that welded in insert stuck up almost 0.400". They are not in the way anymore and all ports should be opened up as equally as can be now.
Was all this really necessary? Maybe not. Can the difference be measured? Probably not. Why did we do this? To be different and to say we did. And because Hot Rod!
Stock:
After we ported and smoothed the inside out:
After the metal insert and hump were milled out and new piece welded in:
After a little smoothing:
My welder really didn't want to weld from the inside for a number of reason mostly due to heat and warping the manifold. I looked into epoxy filler for the small gap but have decided against doing that as there is very little tolerance there and it's fine the way it is.
I'd expect the engine to run a little smoother with some slight power improvement. Number 1 and 2 cylinder will be seeing similar airflow as the others now, after removing those restrictions in blower intake manifold.
We slowed down progress a couple weeks ago to do some research on pulleys. To be a little different and to make things more difficult for us, we took a serious look into what it would take to change everything to an 8 rib setup. There have been several 2.9L Whipples pushed pretty hard recently and some have been held back by belt slip. We thought we would try to get ahead of that.
We spent a lot of time measuring and searching the different size pulleys available off the shelf. I was also curious on what it would take to slow the accessories down a little bit since we are running a 17% overdrive damper. I could talk about this stuff for days but in the end I didn't want to spin the alternator or power steering pump that fast if we could prevent it. The water pump is what it is due to the location and space restrictions. There is simple no room to make the water pump pulley any larger. The A/C compressor pulley is the hardest pulley to obtain in the quest for the 8 rib setup and I think it has to be custom made.
Here are the alternator pulleys I have now. On the right is the stock pulley measuring in with a diameter of 2.060 inches, a bore diameter of 0.67 inches (or 17mm to make it easy) and an offset of 0.35 inches (or 9mm). This guy spins about 3 times for every one turn of the stock damper. With the 17% overdrive damper it's closer to 4 turns. Even though the alternator is regulated by the computer so it isn't completely loaded all the time, the rotor is still spinning and I don't feel the need to test those limits. Talking to some alternator experts, they say more than 15,000 rpm for very long is not recommended. The middle pulley is a 6 rib metal with a 2.44" diameter, about a 21% increase in size. It had the right offset and bore size but needed a little machining in the center to get the correct spacing for the nut on the shaft. This pulley is awesome and what I will run with the 17% od damper if I have to stay with the 6 rib setup. On the left is an 8 rib metal pulley measuring 2.5" (about 22% difference). The offset and bore are correct but I'll have to modify the shaft nut due to the way the center is made on the pulley coupled with the shaft nut only being half threaded. Easy mod.
We needed a pulley for the Whipple to test and see if an 8 rib would work as easily as we hoped. I got my hands on a 3.25 inch 8 rib from a Cobra application and the offset is the same.
Here's a project my dad has been working on. We really want to run an 8 rib belt for a couple different reasons. The power steering pump pulley will have to be swapped out from the 6 rib to an 8 rib. But we are also interested in under-driving the pump due to the damper being 17% over-driven. So, to slow the pump down a bit, my dad researched 8 rib pulleys a little larger than the stock and found a couple pulleys that might be close to useable off the shelf. The big problem becomes the lack of space for the pulley due to the tensioner being right there. The answer is to move the P/S pump over a little. The pulley we found would need the bore enlarged a little to fit the pump shaft and the offset was about a half inch off. That ended up working out great for us. We picked up some 0.500" 6061 aluminum plate and started wildling away at it to make a base plate. We have it mostly figured out but will have to dial in the spacing when we put the pulley on the shaft.
Stock pulley plus a couple 8 rib off the shelf pulleys.
Started with a cardboard template, then a wood template, and then moved to a half inch thick piece of aluminum.
Trying to make things work.
How it will probably sit when finished.
Rough shape for mock up.
Milling it to a useable piece.
Final piece ready for install.
I finally got lucky and found a water pump pulley and an A/C compressor pulley.
The A/C pulley is supposed to be the problem child. Beggar's can't be chooser and I don't know what would make one better than another so I'll take what I can get and see how it does.
We sent the damper back to ATI to get two more ribs cut. They had it less than 24 hours before it was boxed back up and ready to ship back. Impressive.
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Related Threads
?
?
?
?
?
LX Forums Forum
5.2M posts
122.9K members
Since 2004
A forum community dedicated to all LX owners and enthusiasts including Dodge Charger, Challenger, Magnum, Hellcat, SRT8, and Chrysler 300. Come join the discussion about performance, modifications, classifieds, troubleshooting, maintenance, and more!