Racecar Rebuild: its been awhile!

[wetamup2k3g]

Look at how clean the inside of those heads are.

[foxbrand]

^ this, last time I had a valve cover off my rocker arms and shafts had a gold/brown tint to them, although the rocker assemblies for my 6g75 are basically silver/grey like yours, mind if I ask what kind of oil you have been using?


but, my you are moving quickly in your build, keep it up!

[finald8ta]

nice!!!\

[6G72gearhead]

The heads have been rebuilt before, which got all the varnish off, but I run Mobil 1 0w-40. So we'll see how the bottom end looks.

The bottom end isn't off because I'm porting the exhaust side of the head to 40mm.

[6G72gearhead]

Ok, I got the timing belt off today, and actually got it down to basically the shortblock.

Here is a couple more pictures inside the heads. They have RPW valvesprings that I'll have to get checked for proper spring pressure.





We also got the front subframe out to clean it up, I don't have any pictures, but its good I did since there is some surface rust I'll pour15 before reassembly.

Took all day to enhance the previous port work, the intake side is just dandy, but the exhaust ports on these heads suck, and they can flow much better, but you gotta hog them out quite a bit. The guy who did the port work initially did a good job, he just neglected to take the actual size of the port as large as need be to take advantage of the RPW header system I'm using.

So I took this opportunity to open them up even more. Granted they are rough for now, I'll go in an further polish them to get the full effect. They started at 37mm and I took them out to 40mm to match the headers.





The left is the 37mm port, right side is the 40mm






Before all of you go ehrmagerd why did you grind on them with the heads still on the block?!? Relax, the nice thing about taking an engine apart is that you can do this, and then pull the cylinders out the bottom to keep from scoring the cylinder walls. Which is exactly what I'm going to do, leaving the heads on just made it easier to hold them still while I messed with them.

The bottom end looks good, especially since this engine has spent at least 40k of its life above 4k rpms. This is why I enjoy the short stroke of the 6G72, I think its potential as a naturally aspirated engine hasn't been close to unlocked, its very revvable and if I can keep things like the oil pump and water pump and the timing belt happy I'm guessing there is plenty of power to be made in the upper stratosphere of the rpm range.



The oil pan, and windage tray all have the normal oil varnish on them, its not a bad thing to see the golden brown varnish, that means your oil is building up a film and the additives are bonding to the internal parts.

[wetamup2k3g]

What tool do you use to port the heads?

[6G72gearhead]

I used a wire wheel and a couple different grinding stones. The wire wheel takes out more material, but the finish it leaves is not quite so good, so you clean them up with the stones, on the exhaust side the finer grit the better. I DO NOT recommend just going at your heads without a lot of planning and measuring of clearances. You can very easily hit the water jacket or the oil return. Unless you can look at it and have an idea of what needs to be done, leave it for the pro's. Plus they have cool flow benches and can match each cylinder!

Spent most of today just cleaning stuff, but first a look as what the rod bearings and cylinder bore looks like!











The half cleaned subframe



Dirty ol' gearbox



Passenger side of the engine bay all cleaned up



Drivers side disaster area



Passenger side headlight mounting area all cleaned up



Drivers side still in need of tlc



I found some rust on the strut tower that will probably have to be grinded and welded, more on that later, I'm shot.

[6G72gearhead]

I have been busy on this car, I have been grinding off the spots of rust and painting all the bare spots with POUR 15, as well as painting all the seams that might possibly rust in the future. Now its time to spray it down with 3M undercoat to give it a bit more protection.

Here is the cleaned up subframe.


Crank and Girdle






Rack cleaned up and back on the subframe. Still gotta change tie rods.




Some pictures around the shop, the next project is to notch the frame of the S10 and bag it. Gonna pull the cab off the frame and clean it all up as well.










Old junk coilovers, well, the back ones are still good if anyone wants them.


Old Norton Commander project bike.

[Rach3T8G]

You sure have a lot of work on your hands. Are the coils free?

[6G72gearhead]

Well you pay shipping, can't decide if I want to keep the springs for tuning purposes though. The fronts are ruined, the rears I haven't played with, but there is a chance they are busted as well.

[keith6110]

What's wrong with the fronts? Don't want but curious lol.

[6G72gearhead]

What's wrong with the fronts? Don't want but curious lol.

Read my first post for more details, but I basically wrecked the car, the fronts are cracked and seized together. It took a hard hit.

So I have been debating the compression ratio I want to go for this stage of the build. It seems I could have a set of custom Wiseco's for the same price as a set of GTS 10:1's. If I do that I could potentially go to 11+:1 compression ratio. My problem is there is almost no documentation on what the 6G7X heads will handle as far as super high compression. My other dilemma is for SMFWD class I have to run pump gas, which could be E85, but for now I'd at least like to be able to make it run on 91-93. I'll probably do another engine build once I step up to Street GT as my powerband will have to be different and I can run higher octane, not to mention being able to utilize more power.

Another thing I've been looking at is what I want to do for a wheel and tire combo. My current set up is 17x8.5 front and 17x8 rears, which is working very well, however I am limited to a 255 tire, pretty much max. If I step it out to a 9.5 and 9 I can potentially run a 275, which will give me the amount of tire I'm looking for to be very class competitive. I need to get it sorted so I can use this next race season to gather data for custom valving the dampers and really getting the car dialed in so I can start competing nationally.

I have been talking with my fabricator about setting up a battery box mounted to the frame rail just above the transmission mount, and the battery we have decided to go with will weigh just 6 lbs!

We should be able to get started on the strut tower brace, currently trying to design a good solid mount for the firewall section and debating materials. Its looking like the rules are trying to limit/ban the use of exotic materials for non-safety components so ti might be out for a brace. Chromoly is the word currently being tossed about for a replacement.

[6G72gearhead]

Progress has been slow, waiting for the machine shop to finish up the heads and the block. Other then that I've cleaned up a lot of stuff, so it should be starting to go back together fairly soon.

[6G72gearhead]

Well its all back together, so here is whats left of the pictures I've yet to post.

Welding up the new flex joints on the header


Fresh undercoat on top of the POR15 in the fender wells, should keep them well protected from any road debris.




Headers on the new engine after being ceramic coated.




Engine dropped in the car finally!






First start in over 2 years, like nothing ever happened.

http://s138.photobucket.com/user/aut...94b6c.mp4.html

Back on the road to put the body work back on.



Dirty, stock looking, but together at last.



First cone race since it got back together, still on dried out RS2's



BFG Rivals in 255/40/17, these tires are awesome!







Working on getting it dropped lower.




The car has been very fast in regional events, I'm working on getting it set up to perform at the divisional coming up late next month. I'm looking at rolling the fenders out heavily so I can get my roll center lower without rubbing under hard corners. Not to mention the Rivals like camber, so getting up to 2.5-3 degrees should be very beneficial.

Also I've been doing some work on a new intake manifold design, its mostly now up to which throttle body I decide to use.

[wetamup2k3g]

wow, that sounds great!

[mrg7243]

How did you use the POR-15? Just curious as I want to do that to my grand national and the t-bird on the garage.

Also do you still have those top camber plates on the coils?

[master_visionary]

this is great keep up the work

[6G72gearhead]

How did you use the POR-15? Just curious as I want to do that to my grand national and the t-bird on the garage.

Also do you still have those top camber plates on the coils?

POR-15 sticks best to rusted surfaces, so basically I cleaned up the top rust and got rid of the crumbly parts that are falling off anyways and then just brush painted the stuff on. Also if you have bare metal that you want to POR-15, just let it surface rust a little before you paint it on, this will make it stick much better. I'd suggest getting a light coat of wax on any painted surface it may drip on, since you can just let it dry and then pick it with your finger and it will just flake off, which is really handy.

I have the old camber plates if anyone wants them, they should be in good shape still.

I'm working on flaring/rolling the fenders today in order to make room for massive rubber. If I can push them out enough I think I might be able to go to a 275 in the future, which will be insane.

Also, I have a friend who is really good at fabrication, and we are attempting to design a new surge tank for the GTS manifold that will utilize a larger throttle body. I'm going to hold back on most of the details for now, but I feel it should work very well to make some very nice power gains.

[M-Rod]

Glad to see this car is up and running again. I may have missed it or forgot, but you do have an LSD installed, right?

[6G72gearhead]

Yeah, I got one way back when the Quaffe was the one to have. I see everyone is going to a wavetrac and I don't know anything about those. Makes a huge difference, and with a good box limits breakage to cv axles which are free at O'Reilly's, lol.