kirk280zxv8 Posted January 16, 2010 Share Posted January 16, 2010 i have a 83 zx coupe n/a i have 390 gear what would it take to put a r200 3.54 for more top end i have th-350 and sbc with 24.5 tall tire would r200 bolt up mabey if not what do i need to do? thanks grumpy Quote Link to comment Share on other sites More sharing options...
rsicard Posted January 20, 2010 Share Posted January 20, 2010 Grumpyvette: Now I really need your help. Just starting to run the 383 SBC on a run-in stand. Got the ignition timing close to where it should be. The problem is that about below 1500 RPM the engine dies out. The carb is a 650 cfm Holley and it ran a 1998 Vortec 350 SBC on the engine stand from what I can remember was OK. Seems the only difference is the Vortec intake versus intake for AFR 195 cylinder heads. Hard to imagine a big vacuum leak as the plugs show it running rich. The camshaft is a solid roller 236 intake and 242 exhaust at .050. Need your suggestions. Need to get this thing to idle. Please provide several possibilities. Thanks and please advise. Quote Link to comment Share on other sites More sharing options...
rsicard Posted January 20, 2010 Share Posted January 20, 2010 Grumpyvette: Ignore the previous post by myself. Thought I had left a pipe plug out of the intake manifold. Just went to look at it and found the PCV hose disconnected at the carb, thus the large vacuum leak. Thanks anyway. Will run it again tomorrow weather permitting. Quote Link to comment Share on other sites More sharing options...
rsicard Posted January 20, 2010 Share Posted January 20, 2010 Grumpyvette: Further run-in news. Plugged the PCV vent and ran the engine. Now if I modulate the choke diaphragm to about 1/4 open it will run smooth but about 2000 RPM. Lowering the throttle, the engine will quit. Closing the choke further will get it to run rich, opening more than 1/4 it likes to die also from 2000 RPM. The carb is a 650 CFM vacuum secondary Holley. It does not seem that the idle adjust will cure this situation. It has a high lift 236/242 .05 duration cam 383 SBC. Need your experienced suggestions PLEASE. Quote Link to comment Share on other sites More sharing options...
grumpyvette Posted January 20, 2010 Author Share Posted January 20, 2010 (edited) always drop back to basics have you verified TDC on the damper and timing tab? did you degree in the cam or just DOT-to-dot install it? whats your fuel pressure? have you verified the carbs float levels? does fuel run out the site holes at idle? are the needle& seat valves working correctly? whats your ignition timing? have you done a compression check? whats your plenum vacuum? have you verified the engine got no vacuum leaks? whats the oil pressure? have you adjusted the valves at idle? does the distributor timing advance with rpm increases? have you tried a different carb? what are the plugs gaped at? does this happen without an air filter? have you verified you've have functioning power valves? what jets are you using? is there visible fuel flow from the boosters? whats your battery voltage? whats your exhaust back pressure? are you totally sure the fuel free of water and fresh? if you were local Im sure I could get to the cause in a few minutes and correct it, checking and correcting this stuff just takes a few tools and experience Edited January 20, 2010 by grumpyvette Quote Link to comment Share on other sites More sharing options...
rsicard Posted January 20, 2010 Share Posted January 20, 2010 Grumpyvette: Thanks for the assistance. The plenum vacuum is 15-17 inches. The valves have been adjusted cold to .016. The Carb is the big unknown here. Used it on a 350 Vortec with the same carb and the 350 seemed to run OK. A 5 gallon jerry can is sitting above the carb partially filled with fuel the bottom of which feeds the carb so pressure is minimal. Fuel is visible at boosters. Jet size unknown. Suspect 67F/73R. Cam timing checked. Plugs at .045" gap. Engine runs smooth from 2000 RPM on up. Just does not want to idle below 1500 to 2000 RPM. The only other carb immediately available is a Quadrajet in the process of being rebuilt. Battery voltage comes from a running truck (13.8 volts) as the test stand has welding cable and clamps for power sourcing from a battery in a vehicle. Distributor is a nearly new MSD Street Fire 8362 HEI type with only short run times on it. Ignition timing is ball parked around 10 degrees advanced for now until such time as I get it to idle and check and set centrifugal and vacuum advance. Just wondering, does the 650 CFM holley idle circuit dependent on the primary power circuit??? That is to say, if putting a larger size primary jet enrichens the idle circuit??? Please advise. Thanks. Quote Link to comment Share on other sites More sharing options...
rucus01 Posted January 20, 2010 Share Posted January 20, 2010 Grumpyvette: Thanks for the assistance. The plenum vacuum is 15-17 inches. The valves have been adjusted cold to .016. The Carb is the big unknown here. Used it on a 350 Vortec with the same carb and the 350 seemed to run OK. A 5 gallon jerry can is sitting above the carb partially filled with fuel the bottom of which feeds the carb so pressure is minimal. Fuel is visible at boosters. Jet size unknown. Suspect 67F/73R. Cam timing checked. Plugs at .045" gap. Engine runs smooth from 2000 RPM on up. Just does not want to idle below 1500 to 2000 RPM. The only other carb immediately available is a Quadrajet in the process of being rebuilt. Battery voltage comes from a running truck (13.8 volts) as the test stand has welding cable and clamps for power sourcing from a battery in a vehicle. Distributor is a nearly new MSD Street Fire 8362 HEI type with only short run times on it. Ignition timing is ball parked around 10 degrees advanced for now until such time as I get it to idle and check and set centrifugal and vacuum advance. Just wondering, does the 650 CFM holley idle circuit dependent on the primary power circuit??? That is to say, if putting a larger size primary jet enrichens the idle circuit??? Please advise. Thanks. Get a fuel pump and a pressure regulator. And 10 degrees is no where near enough for that cam. That cam will need at least 16-20 to idle well. Quote Link to comment Share on other sites More sharing options...
RB26powered74zcar Posted January 20, 2010 Share Posted January 20, 2010 Great thread!! Plus, the post count was on 66six, so I changed that... Quote Link to comment Share on other sites More sharing options...
rsicard Posted January 21, 2010 Share Posted January 21, 2010 rucus01: Understand the need for fuel pump and pressure regulator. Will attempt to pressurize the jerry can to a regulated 6 PSI. As said, the engine runs fine above 2000 RPM. Already stated that the ignition will fine tuned once the idle situation is fixed. Advancing or retarding the ignition did not cure the idle situation. Talked to a local performance engine builder and he recommended that the carb idle circuit is not functioning properly perhaps due to the low fuel pressure. Tearing apart the carb and the primary fuel bowl has some crusty stuff on the walls. Hard to find a minimal rebuild parts kit with primarily gaskets etc. Power valve feels OK. Need to test with vacuum pump and gauge. Don't want to spend much money on carbs as I would like to go to Electronic Fuel Injection (EFI) which is infinitely adjustable. Quote Link to comment Share on other sites More sharing options...
grumpyvette Posted January 21, 2010 Author Share Posted January 21, 2010 (edited) personally if it was my car Id swap to a different carb as a, quick test rather early in the test & tune process to see the results, as that would tend to eliminate some potential testing if it cured or failed to cure the problem, I picked up and rebuilt a 600 edelbrock carb at a yard sale for $15 that I use just for testing Edited January 21, 2010 by grumpyvette Quote Link to comment Share on other sites More sharing options...
kirk280zxv8 Posted January 21, 2010 Share Posted January 21, 2010 Grumpy ,my car was doing the same so i used the wide band at my shop and primary jet was to big a 66 primary and 77 secondary. Airfuel was like 10 so i put a 64 jet for the primary air fuel now 14.9-15.3 cruising speed under a load perfect.And when i get on it it was about 13.9-14.2. I would recommend to find a wide band to borrow to take out the guess work. I was wanting to burn my car to the ground before that.Your jet might be to big and loading up at idle. Also make sure when you set the timing that you disconnect tha vaccum advance. Mine is set at 30 deg, hei distributor thats my 0.01$ Quote Link to comment Share on other sites More sharing options...
rsicard Posted January 21, 2010 Share Posted January 21, 2010 Grumpyvette: Have already entertained that thought. Will pick up another carb or rebuild the Quadrajet already broken down. I have already studied the Quadrajet and it is relatively simple and I don't understand the Holley to the same extent. Opened up the Holley and found crusty stuff. Somewhat difficult to find a rebuild kit for the Holley. Quote Link to comment Share on other sites More sharing options...
txevo Posted January 22, 2010 Share Posted January 22, 2010 ok this is one for you my 79na has the 2 4 and 6 cy not working got spark and at this time looks like ije are fine with good compr Quote Link to comment Share on other sites More sharing options...
rsicard Posted January 22, 2010 Share Posted January 22, 2010 Grumpyvette: Latest news. Rebuilt the Holley 650 carb. Found some crude blocking what appeared to be the idle fuel port. Disassembled, dunked in carb cleaner, traced and cleaned all passages with aerosol can of carb cleaner with fine tube nozzle. Reassembled carb, assembled to engine. Started engine and set timing more advance according to timing light with no distributor vacuum. Still need to do more fine tuning checking mechanical and vacuum advance. Now it seems to idle just fine. Set idle jets to 2 turns out and left at that value. All this because of crud in the carb. Once cleaned runs fine. Engine is on a run-in stand with no mechanical load, only flywheel mounted. Have about 1/4 of 5 gallon quantity gravity tank and carb fuel bowl level below site plug and engine runs fine. Have a LARGE aluminum radiator and Ford Tarus two speed fan wired to HIGH speed behind large radiator and it still does not take long for the temp gauge to go above 180 degrees with a few minutes of running. Need to sort that situation out. Quote Link to comment Share on other sites More sharing options...
grumpyvette Posted January 23, 2010 Author Share Posted January 23, 2010 ok this is one for you my 79na has the 2 4 and 6 cy not workinggot spark and at this time looks like ije are fine with good compr id need a good deal more info on your combo of engine and components you used ,without knowing the engine size type and your ignition, cam, and induction system, fuel system, ETC. figuring out the probable cause is a bit of guess work at the best of times Quote Link to comment Share on other sites More sharing options...
grumpyvette Posted January 23, 2010 Author Share Posted January 23, 2010 Grumpyvette: Latest news. Rebuilt the Holley 650 carb. Found some crude blocking what appeared to be the idle fuel port. Disassembled, dunked in carb cleaner, traced and cleaned all passages with aerosol can of carb cleaner with fine tube nozzle. Reassembled carb, assembled to engine. Started engine and set timing more advance according to timing light with no distributor vacuum. Still need to do more fine tuning checking mechanical and vacuum advance. Now it seems to idle just fine. Set idle jets to 2 turns out and left at that value. All this because of crud in the carb. Once cleaned runs fine. Engine is on a run-in stand with no mechanical load, only flywheel mounted. Have about 1/4 of 5 gallon quantity gravity tank and carb fuel bowl level below site plug and engine runs fine. Have a LARGE aluminum radiator and Ford Tarus two speed fan wired to HIGH speed behind large radiator and it still does not take long for the temp gauge to go above 180 degrees with a few minutes of running. Need to sort that situation out. Im glad to see you make progress,but Id point out engines NORMALLY run coolant temps of 180F-210F, and if you have not verified the damper and timing tab TDC and your vacuum readings, fuel pressure, ignition advance curve and FUEL/AIR RATIO ,ETC., ETC. your just guessing always drop back to basics have you verified TDC on the damper and timing tab? did you degree in the cam or just DOT-to-dot install it? whats your fuel pressure? have you verified the carbs float levels? does fuel run out the site holes at idle? are the needle& seat valves working correctly? whats your ignition timing? have you done a compression check? whats your plenum vacuum? have you verified the engine got no vacuum leaks? whats the oil pressure? have you adjusted the valves at idle? does the distributor timing advance with rpm increases? have you tried a different carb? what are the plugs gaped at? does this happen without an air filter? have you verified you've have functioning power valves? what jets are you using? is there visible fuel flow from the boosters? whats your battery voltage? whats your exhaust back pressure? are you totally sure the fuel free of water and fresh? Quote Link to comment Share on other sites More sharing options...
txevo Posted January 23, 2010 Share Posted January 23, 2010 grup as far as can tell it is all stock I was told that the ije have a smal screen in them and they might have somthing in them..the thing that got me was the 2 4 and 6 thing...was also thinking that it may be a comon prob. Even it was 1 3 5 HELP :fmad::fmad::fmad: Quote Link to comment Share on other sites More sharing options...
grumpyvette Posted January 23, 2010 Author Share Posted January 23, 2010 without knowing WHAT ENGINE your referring too, or if its a CARB, or INJECTION, or what IGNITION, I can,t give you a reasonable suggestion as to where to look Quote Link to comment Share on other sites More sharing options...
kiwi303 Posted January 31, 2010 Share Posted January 31, 2010 Heres a parts Question, what do you think of Probe SRS pistons and 4340 Lightweight I beam rods? Quote Link to comment Share on other sites More sharing options...
thepicklefish Posted January 31, 2010 Share Posted January 31, 2010 hi, i have a 260 i plan to put a V8 in. Ive been researching but i still have some questions. 1. I plan to use this engine (http://www.blueprintengines.com/popular_configurations/index.html?topic=specs&pc_id=21) with a T56. I read that the clutch, pressure plate, flywheel and belhousing will fit, is that true? if not, what do i use instead. 2.I keep hearing everyone talk about the JCI mounting kit, but i cant find where to buy one at. also how good is the stealth conversions mounting kit from JTR? 3. Can you use the motor and tranny mount out of a camaro or other car, or do u have to buy modified ones? Or do they come with the mounting kits? 4.How well do u think the rear end will hold up against that motor? 5.How good are parts from the Z Store when it comes to V8 conversions? I would really appreciate the help, thanks Quote Link to comment Share on other sites More sharing options...
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.