4 Door Tahoe project

[deejaaa]

.................tranny does hold back, at higher speeds. It is more noticeable with the torque converter locked.......................

what do you mean. is it slipping? how does the manual 4L80 feel? shift rough/smooth.

 

[6.2 turbo]

The shifts are firm,not harsh. The slipping I feel is the torque converter,it feels like a 3000 stall,and at low speeds it is very loose. I can also slip the lock up clutch,if I hit the switch at full throttle in 3rd. It is awesome being able to manually shift when you want to and lock up also. If I change to 3.73 or 4.10 gears the converter will tighten up some. The tranny also has the Transgo HD-2 kit,but with the softer settings for now.

 

[deejaaa]

The shifts are firm,not harsh..................

would you recommend this for a daily driver?

 

[6.2 turbo]

If you don't mind full manual shifting I would recommend it. The only thing I wish it would allow lockup in manual first gear,but I think that is the way GM designed it. If you had a computer,and had the shifter in 3 or od position ,you could probably ,manual lock up the converter ,while the computer commands 1st gear. I could possibly also do this with a 2 position toggle switch,but for now its fine. One thing that is nice,you can leave the converter locked up,and shift down,to 1st when slowing down,and stop normally. Then when taking off and you hit second,it is instantly in lockup,this would work best with lower rear end gears,or an engine with lot of torque. The way the Tahoe is set up now ,it makes the gear jump fairly large. I would also recommend a shifter with a reverse lockout,for safety. I used a B&M truck megashifter. It took forever to get it installed,and adjusted . It is still not 100% adjusted right,but really close,and works perfectly. You could also make your own full manual harness,for free,all it is is 3 wires connected. But you still might want the billet epc plug,the line pressure might be to low or high with the epc solenoid in place.

 

[turbonator]

how do you find the coolant temps on your motor? you filled the block just to 1 inch from the top, right?

 

[6.2 turbo]

It has yet to get over 130 degrees. The oil was 160 degrees at the filters. I will need a thermostat for winter,using a gas radiator also. Keep in mind I have drove like only 5 miles. Tomorrow I will check my boost pressure,and maybe a head bolt. I probably should have annealed the head gaskets. I sure do have the worst luck with head gaskets. I will stick to the high compression until it blows about 3 sets . I really would like to make it work. I might get studs,but I'm not convinced that they really help,guess I'll try the bolts at least one more time.

 

[6.2 turbo]

Here is some pictures of the 4 inch down pipe. It took me forever to make it. I built a complete 4 inch system,and it cost less than $ 40 . Most the pieces were used, or left over scraps ,but still very good shape.

 

[6.2 turbo]

I drove it to work today ,it runs and drives great,25 psi max boost,and only a puff of black smoke from a dead stop. Checked the over flow,and it was full to the top,and bubbling. I took both heads off tonight. I had to use a pipe to loosen the bolts,they were not loose ,I checked one it was 135 ft lbs. There is also a problem with my fuel system I can here it cavitating,but is ok for now. I will ether return to the inlet of the pump or go back to a dead head system. I don't really want to dead head, because eventually I want to run high fuel pressure at full throttle only. Maybe use a fmu like turbo gassers. I would love to see 100 psi lift pump pressure at full throttle ,and 10 psi at normal driving. The fun stuff will just have to wait I guess.

 

[turbonator]

Here is some pictures of the 4 inch down pipe. It took me forever to make it. I built a complete 4 inch system,and it cost less than $ 40 . Most the pieces were used, or left over scraps ,but still very good shape.

that is truly awesome... nice work... does it make a difference having your manifolds wrapped? where did you buy your heat wrap?

 

[turbonator]

I drove it to work today ,it runs and drives great,25 psi max boost,and only a puff of black smoke from a dead stop. Checked the over flow,and it was full to the top,and bubbling. I took both heads off tonight. I had to use a pipe to loosen the bolts,they were not loose ,I checked one it was 135 ft lbs.

i have a crazy thought, what if a guy drilled 2 holes, one on one side if the face of the head, and another on the other side, and then drilled the same holes directly below them on the block and built 4 gusseted angles and then bolted one to the head and the other to the block on each side, then passed a grade 8 bolt through the hole in the brackets and tightened the hell out of it, it would act like the extra head bolt and put more clamping force on the front of the head/block.... it sounds confusing, but might work...

 

[6.2 turbo]

That might work, in the rear, but in the front you have brackets in the way. Another thing,it might be to far away from the problem area ? I'll have to think about that one a little . I got the header wrap on Ebay. Don't know if it helps spoolup, but at least I didn't have to worry about all those stupid factory shields.

 

[turbonator]

That might work, in the rear, but in the front you have brackets in the way. Another thing,it might be to far away from the problem area ? I'll have to think about that one a little .

after i posted about the extra head bolt i went out and looked at our 6.2l heads, the place that a bolt would be ideal is right where the oil drains back down into the block, it is a curved place too, would be a real bitch to machine the hole for the bolt.. as for the brackets, maybe it could be just the ones bolted to the heads, and the holes could be drilled tapped right where the 6. LD is, just down from the oil supply, say the brackets are one inch thick,, i am not sure, but this space is still open when the accessories are bolted on, and there is alot of meat in this area for drilling...on the back of the head the holes are there already, just a matter of finding a way to clamp down to the block.... what did you mean about the rods down the coolant passages? to give it more rigidity back there? or to drill the head so it passes through to clamp the head down better? could be done like that if it was a 12.9 bolt with a washer on it and it was poured in the cement.... just need to cut like a 30 degree shim/washer to put under the nut inside the head...

 

[6.2 turbo]

I was thinking the rod could support the cylinder wall at the top,and if left sticking out a little would support the gasket also.

 

[turbonator]

When you two guys get to "Spit Ballin" ideas late at night, keep in mind that usually I am unable to sleep for at least a couple of nights afterwards.....trying to figure out how to implement all your ideas...LOL.:agreed:

 

[6.2 turbo]

I checked my orings,and for some reason both rear ones were only sticking up about .005 ,just at the water port. I put a new oring in the pass rear,and it only stood up .006. They were supposed to be .010. I ended up shimming both rear orings with .010 copper wire,only at the water ports. I test fitted a Victor Reinze 4021,did not flip the fire rings. I looks like it might work. The orings catch the fire ring,just out side of the wire that's in the fire ring,but do not miss the metal part at all. These are the only gaskets with a wide enough fire ring. Cometics or copper gaskets don't seem to work for me.

 

[6.2 turbo]

Got the heads torqued to 130,had to toss two bolts that just stretched. I think next time it will get studs. Got the rockers,and valve covers on,used rtv instead of cork,they had been leaking pretty good. One valve cover had a crack at a bolt hole,this was probably some of the leak. I brazed the crack on both sides. If these head gaskets blow immediately, its going to get lower compression and head studs.

 

[turbonator]

Got the heads torqued to 130,had to toss two bolts that just stretched. I think next time it will get studs. Got the rockers,and valve covers on,used rtv instead of cork,they had been leaking pretty good. One valve cover had a crack at a bolt hole,this was probably some of the leak. I brazed the crack on both sides. If these head gaskets blow immediately, its going to get lower compression and head studs.

we have discussed your idea of the aftermarket "dowels" to support the gaskets, and we are going to try it when we pour the cement in our block... they will be machined slightly oblong at the top to support as much of the gasket as possible, and not change the flow characteristics of the coolant... also they will be bent some what so they are not right tight to the cylinder wall as not to cause hotspots in the cylinder, and when they are totally machined and ready, they will be ceramic coated(VHT rattle-can) so they do not oxydize..... you could still do it also by taking a long cement bit and drilling down and glueing them in the cement with JB, or? just to seal so there is not water seeping into your cement.....

 

[6.2 turbo]

Are you going to oring the block also ?

 

[turbonator]

Are you going to oring the block also ?

Yes, we have the Isky tool, and will be "o-ringing", with .015" protrusion. Been looking at the tool abit, and might design something to o-ring the head also (leaving the pre-cup alone). We would really like to be able to have a "safe 40psi" ....LOL.

Tomorrow, we will start our metal roofing on the shop, we have some of our electricity hooked up, so we can work a bit in the evenings too now.

 

[6.2 turbo]

I believe my copper gaskets would have worked with either a receiver groove,or o-rings in the head . I will defiantly hang on to them,just don't feel like dealing with them right now.