IrvinM Posted August 24, 2013 Report Share Posted August 24, 2013 To make the story short: I can't decide weather to install the plate with the notches facing away from the engine or facing towards the engine. I bougt a K662 WK663 kit from ebay. Help please. I might place the notches facing towards the engine since the plate on the manifold seems will run parallel to the other side of the notches on the carburetor plate. The plate on the manifold will guide the carburetor plate in the same direction, and the carburetor plate will become more stable in the direction and alignment. By the way, the plate on the manifold is the plate bolted onto the manifold shown at the "tip" of the carburetor plate in the picture, where the notches are at. Quote Link to comment
IrvinM Posted August 24, 2013 Author Report Share Posted August 24, 2013 Here is the other picture, notches facing the other way Quote Link to comment
q-tip Posted August 24, 2013 Report Share Posted August 24, 2013 The kit that I got with my kit has 2 plates. The factory bolt spacing one the manifold is smaller than the spacing on the weber. The plate with the countsink holes in it(the one in you pictures) goes on the bottom and the other plate bolts on top. I suggest getting a file and taking the high spots off of the 2 adapter plates so the will seal better. And lock use blue locktite on the bolts for the bottom plate and the one that bolts to it, it will come loose and create a terrible vacuum leak Quote Link to comment
620Turbo4X4 Posted August 24, 2013 Report Share Posted August 24, 2013 You might want to look for a different intake/exhaust manifold. My truck had that same intake and exhaust bolted together like yours and the intake would get so hot, that the fuel in the webber would boil, then dump fuel down the intake every time it was shut down hot. A 1/2" thick insulator helped a bit… but it would still boil over. I never had this problem with the hitachi. They seem to cope with the heat/fuel boiling better. I got rid of that intake/exhaust setup on mine and problem went away. Quote Link to comment
IrvinM Posted August 24, 2013 Author Report Share Posted August 24, 2013 You might want to look for a different intake/exhaust manifold. My truck had that same intake and exhaust bolted together like yours and the intake would get so hot, that the fuel in the webber would boil, then dump fuel down the intake every time it was shut down hot. A 1/2" thick insulator helped a bit… but it would still boil over. I never had this problem with the hitachi. They seem to cope with the heat/fuel boiling better. I got rid of that intake/exhaust setup on mine and problem went away. What intake did you get? I've heard that you can put a L16 intake on the L20B (the one I have). I don't know if this would fix a problem like this. But which way should I face the notches from the plate adapter? Quote Link to comment
Sealik Posted August 24, 2013 Report Share Posted August 24, 2013 I installed the plates this way.... Also opened up the throat..... 1 Quote Link to comment
620Turbo4X4 Posted August 24, 2013 Report Share Posted August 24, 2013 I think the notches were supposed to provide clearance for the air injection tubes that are welded up on yours. My truck uses a 1 piece adapter that is offset to the outside for the smog tubes (If I had them) Im using a '79 620 intake and custom header. Look for anything that does not have the exhaust manifold directly bolted to the intake. A liquid heated intake would be the best. Quote Link to comment
IrvinM Posted August 24, 2013 Author Report Share Posted August 24, 2013 Thanks a lot for the help! Tonight when I come back from work I'll install the carburetor. I will check for any high changes in temperature in the intake manifold too, and I will cut the gasket blocking the fuel intake. Quote Link to comment
IrvinM Posted August 24, 2013 Author Report Share Posted August 24, 2013 By the way, is there anything else that I should know before installing this carb? Quote Link to comment
620Turbo4X4 Posted August 24, 2013 Report Share Posted August 24, 2013 Your throttle cable is in pretty sad shape. The fuel boiling was my #1 problem. Nothing worse than coming out of the store after just 10 minutes and your engines completely flooded… Mine, if sat overnight would boil the float bowl completey empty, so I would have to crank it about 20 seconds just to get fuel in the bowl in the morning. Quote Link to comment
Sealik Posted August 24, 2013 Report Share Posted August 24, 2013 By the way, is there anything else that I should know before installing this carb? When installing the plates...<...bolts....use Loctite/threadlocker. They have a tendency of backing off. Quote Link to comment
LenRobertson Posted August 24, 2013 Report Share Posted August 24, 2013 Any reason not to use the sheet metal heat shield that is under some Hitachi carbs under the Weber adapter? Or would it do more good to use the Hitachi plastic insulator plate? Or maybe both? I know it would add more gaskets, but seems like that would be worth it if it helped with the carb overheating problem. I'm getting close to trying a 32/36 on the L20b in my 510, so I may experiment with this idea unless someone knows it won't work. Len Quote Link to comment
Sealik Posted August 24, 2013 Report Share Posted August 24, 2013 I have a 'factory' heat shield under my intake. 1 Quote Link to comment
IrvinM Posted August 25, 2013 Author Report Share Posted August 25, 2013 I have a 'factory' heat shield under my intake. I think I will be needing one of those, and by the say Sealik, do you have that fuel boiling problem with your carb? it looks like it is a Weber. Quote Link to comment
EricJB Posted August 25, 2013 Report Share Posted August 25, 2013 That's how you do right there. Take the time and make a nice plenum under the carb. Quote Link to comment
Sealik Posted August 25, 2013 Report Share Posted August 25, 2013 I think I will be needing one of those, and by the say Sealik, do you have that fuel boiling problem with your carb? it looks like it is a Weber. It seemed to run fine...that said I could of drilled holes in the side of the U67 and ran coolant through the intake. I eventually did....but that was for a K14 intake....not for the down draft. Yes....that is a 32/36 and was replaced with a new 38, which...now it sits on a shelf. As of today I'm running 46 SUs....big improvement Quote Link to comment
q-tip Posted August 26, 2013 Report Share Posted August 26, 2013 I don't have the "heat shield" under my carb, have no problems with fuel boiling. USE BLUE LOCKTITE ON ALL BOLTS!!!!! If you don't they will rattle loose and cause some problems.... Quote Link to comment
620Turbo4X4 Posted August 26, 2013 Report Share Posted August 26, 2013 Just to clear up any confusion… The fuel boiling problem I was experiencing with the weber was from using the exhaust heated intake that is directly bolted to the exhaust manifold with 4 bolts like this, Same intake IrvinM has… One of the 4 bolts that hold them together can be seen just under the bottom left carb stud in his photo. Flooding wasn't from a lack of heat shields... They were still there. In addition to the (2) 1/4" thick insulators I had under the carb I even wired the bi-metallic spring (thermal riser valve) in the open position to divert exhaust away from intake to no avail. Nothing helped the fact that the two are bolted together directly under the carb. My current setup uses no heat shields either. With the intake and exhaust separate now, no problems with fuel boiling. If anything the carb is running a bit cold. Thinking I might need to hook up the water line to the intake before winter comes... Quote Link to comment
q-tip Posted August 27, 2013 Report Share Posted August 27, 2013 Perhaps you're air fuel mix was too lean causing high egt? I have the same manifolds on my 620 and have had zero issues Quote Link to comment
620Turbo4X4 Posted August 28, 2013 Report Share Posted August 28, 2013 Pretty sure A/F ratios were close. Never had any lean mis-fires or hesitation with cold engine and manifold never got that hot look, like you see on turbo manifolds and turbine housings (bluish tinge to the rust) Couldn't tell much from the plugs cause they were always black from being flooded. Maybe the ticket is not running the heat shields with that manifold setup? Glad your not having the boil over problem I had. Hopefully Irvin won't have it either. It eventually blew the head gasket from all the hydro-locking. That's okay though… Got me busy getting my rebuilt engine together, and a crack free block for my turbo engine I'm currently building. L20b Bored, balanced, and decked W/ .030 L18 Pistons, ARP Main & head studs, and rod bolts, Ported peanut head,10:1 comp., Isky 270 cam, 32/36, Custom Tri-y to 2-1/4 pipe-all stainless Night and day difference in power. Feels like I took 1000lbs. off the truck!!! Quote Link to comment
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.