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Ive got an opinion question for you. I am planning out my V8 swap and for my 1st motor I am gonna pull a complete turn key from a wrecked car. My two choices were either a Vortec 5.7 from a 97 Tahoe or a carbed 5.7 out of a 80'2 model car/truck. I will run a T5 trans along with it. Any thoughts on the best path for a 6 month temporary motor?

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Ive got an opinion question for you. I am planning out my V8 swap and for my 1st motor I am gonna pull a complete turn key from a wrecked car. My two choices were either a Vortec 5.7 from a 97 Tahoe or a carbed 5.7 out of a 80'2 model car/truck. I will run a T5 trans along with it. Any thoughts on the best path for a 6 month temporary motor?

 

the 97 motors most likely in better condition, less wear, rust and mileage and has the better vortec heads if its temp ID go that route

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Ok this question really has no huge rush but I cant find the answer and its buggin me. On my trottlebody (twin 58mm for tpi) it has a cover on top, it is just a hollow void but it opens into the throttle body. There is a gasket and everything. I looked at the factory one also and it has the same opening. Im lost wtf is this for? Im guessing a diffrent application might need this open for a sensor or something? Im wondering could I fill in that hole and not worry about it? Thanks again

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Ok this question really has no huge rush but I cant find the answer and its buggin me. On my trottlebody (twin 58mm for tpi) it has a cover on top, it is just a hollow void but it opens into the throttle body. There is a gasket and everything. I looked at the factory one also and it has the same opening. Im lost wtf is this for? Im guessing a diffrent application might need this open for a sensor or something? Im wondering could I fill in that hole and not worry about it? Thanks again

bbk-1544_w.jpg

a NAME PLATE goes on top, theres DOZENS to choose from available

 

http://www.tpis.com/index.php?module=catalog_page&catalogPageNumber=162&catalogCategory=%28L98%2FLT1%29+Dress+Trim

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hellllp ,I have a 400 in a z and cant get fuel pressure right it jumps all over the board. tried 2 different pumps 3 regulators. the last pump was a holley red which ,according to summit puts out 7 psi and requires no reguator. in my car it put out 15 psi . I cant figure it out .the only thing I havent tried yet is bypassing the factory line. there is a kink in the metal fuel line where I bent it I hope maybe the restriction in the line is causing this.

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hellllp ,I have a 400 in a z and cant get fuel pressure right it jumps all over the board. tried 2 different pumps 3 regulators. the last pump was a holley red which ,according to summit puts out 7 psi and requires no reguator. in my car it put out 15 psi . I cant figure it out .the only thing I havent tried yet is bypassing the factory line. there is a kink in the metal fuel line where I bent it I hope maybe the restriction in the line is causing this.

 

IF you’re not using a RETURN LINE and a bye-pass style fuel pressure regulator that problems common, it’s NOT common with a decent 3/8" or larger fuel lines, (BOTH feed AND return lines) matched with a bye-pass style fuel pressure regulator.

dead head style fuel pressure regulators are famous for that crappy control.

naturally youll need to verify the carbs set up corretly with the correct jets,power valves, float levels etc, also, but the problem your describing is far more common to the dead head fuel pressure regulator designs.

 

http://www.centuryperformance.com/fuelish-tendencies-understanding-fuel-pressure-and-volume-spg-140.html

 

http://www.centuryperformance.com/fuel-system-troubleshooting-spg-142.html

 

FUEL PRESSURE REGULATORS DEADHEAD vs BY-PASS STYLE

 

dead head regulators seldom allow a stable fuel system pressure, you NEED a by-pass style system with the regulator mounted close to the carb, you can ignore the nitrous part of this diagram if your not running nitrous but the concept of the higher pressure feed bleeding off excess pressure at the regulator so that the carb sees a constant feed pressure is valid. it may help if you understand the difference in concept of how the regulators work

 

PRESSURE IS THE MEASURE OF RESISTANCE TO FLOW

 

THE DEAD HEAD STYLE REGULATOR

Works with a spring on a valve that allows the valve to open once the DIFFERANCE IN PRESSURE between the sides of the regulator valves fuel lines has changed

Think of it as a door that has 7-10psi on the feed side and you want lets assume 5.5 psi at the carb

as the fuel pump fills the line it eventually (fractions of a second) reaches the point where there’s a volume of fuel past the valve with enough pressure to allow BOTH the SPRING and the fuel pressure past the valve to close the valve until the fuel is reduced to the point that the SPRING and the remaining fuel pressure/volume beyond the valve can not hold the valve closed and the valve is force open and held open until, that difference in pressure is restored. now lets launch the car hard, the pump that had maintained 8-10 psi to the regulator, 5.5 psi past the valve and the spring in the regulator is now fighting the fuel in the line feeding the regulators inertia, and the sudden drop in pressure as the throttle drops full open in the carb, what the pump sees is the full 8-10 psi or MORE the regulator sees a sudden drop off to near zero and it opens wide, if the fuel pumps able too it tends to flood the fuel bowl for a second then the valve slams shut, until the pressure drops off as you hit each gear the cycle repeats, the result is a surge in pressure and a rapid drop off in volume then a rapid flood of fuel that rapidly cycles as you go down the track

if you had a accurate fuel pressure sensor at the carb you’ll see a rapidly cycling pressure/flow

if some crud gets stuck in the valve it cant close and your carb FLOODS OUT, because it must fully close every few fractions of a second to work correctly

 

the by-pass regulator functions in a totally different manor

Assuming the same set-up but you replace the regulator with a by-pass style regulator, the by-pass regulator works by opening a valve too a much lower pressure path for the fuel to return to the tank, the open fuel return line. Anytime the pressure exceeds the 5.5 psi, you’ve set it to, so the fuel line to the carb can only see a max at that 5.5 psi. now the pumps sitting there potentially supplying at 8-10psi just like before, but it can never exceed 5.5 psi because the bye pass regulator bleeds of any excess the pump supplies. but lets look at your launch, if the pressure drops to 6, 07 psi nothing changes at the carb, it it increases to 10 or 12 psi, nothing changes at the carb ,if it drops to 5.5 psi or less the valve to the bye pass line will close but that’s seldom a problem, it the sudden changes in pressure and over pressures that happen when you suddenly change the fuel flow required or the (G)loads on the system that potentially screw things up, the bye-pass regulator style regulator isolates the carb and maintains the desired 5.5 psi FAR MORE COBNSISTANTLY

Now let’s assume the spring get weak over time or the adjustment gets set at 4 psi in error, with the bye-pass style you’ll probably never notice, if you had a accurate fuel pressure sensor at the carb you’ll see a rock steady pressure/flow

Should some crud get stuck in the valve and it can’t close NOT MUCH HAPPENDS, because its normally OPEN not closed

If you check you’ll see MOST EFI systems are BYE-PASS regulated designs also due to control and reliability issues

 

But on the dead head the cycle just gets about 20% more erratic and more frequent in the cycles, further weakening the spring over time

 

 

 

btw your fuel pump tends to run under less stress and run cooler with a by-pass style regulator also

_________________

if you can,t smoke the tires from a 60mph rolling start your engine needs more work!

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where would be my best bet for finding (year and model if known) a passanger side top mount alternator bracket for a sbc tpi? also If the car is 90% drag racing would I be better off with a tentioner or without. I could think of pros and cons each way. Or would I be better making the alternator pivot and lock in bolt

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1981 280ZX turbo. Mostly stock. Long block has only 1000 miles since overhaul by Nissan, three years ago. But most of those miles are on road racing tracks doing time trials, surprising many Vettes and Porches. Low miles because do not drive on street much and trailer to tracks. Engine is running strong and smooth making plenty of power, but suddenly starts to make whitish smoke upon start up and when throttle is blipped. Smoke is progressively getting worse. Static compression and leak down is very good. Have replaced valve stem seals, no improvment. It is not using water, but is suddenly using oil. But get this-the plugs look beautiful. When I drained and filtered the oil through fine paper, no lumps but the oil which had not been in long was amazinglly very very black. It is Royal Purple synthetic. Turbo is working fine, but will be installing my spare just in case the seal is shot. But I am not confident that will be it. What else can it be?

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1981 280ZX turbo. Mostly stock. Long block has only 1000 miles since overhaul by Nissan, three years ago. But most of those miles are on road racing tracks doing time trials, surprising many Vettes and Porches. Low miles because do not drive on street much and trailer to tracks. Engine is running strong and smooth making plenty of power, but suddenly starts to make whitish smoke upon start up and when throttle is blipped. Smoke is progressively getting worse. Static compression and leak down is very good. Have replaced valve stem seals, no improvment. It is not using water, but is suddenly using oil. But get this-the plugs look beautiful. When I drained and filtered the oil through fine paper, no lumps but the oil which had not been in long was amazinglly very very black. It is Royal Purple synthetic. Turbo is working fine, but will be installing my spare just in case the seal is shot. But I am not confident that will be it. What else can it be?

 

The very black oil ,and using oil plus, the smoke but yet your passing the leakdown test tends to point to the turbo as a cause, if the engine was the cause the leakdown test tends point that out, and very black oil indicates exhaust or at least combustion contamination. Im going to assume youve got pressurized oil flowing thru the turbo and the high heat and exhaust gases pressent are some how mixing with the cooling oil on the turbo.

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honestly, if youve got a decent welder and a tape meassure and some time, to kill, this is a reasonably easy project

, and it sure beats paying $2k

 

http://www.prwonlinestore.com/low-profilesetsaccessorizedunit.aspx

heres some basic design ideas from pictures

 

 

http://www.mightymount.com/

 

http://www.hotstands.com/

 

http://www.fordmuscle.com/forums/tech-exchange/471021-homemade-engine-run-stand.html

 

http://cgi.ebay.com/ebaymotors/Engine-Start-Test-Stand-Plans_W0QQcmdZViewItemQQ_trkparmsZ72Q3a1205Q7c66Q3a2Q7c65Q3a12Q7c39Q3a1Q7c240Q3a1318Q7c301Q3a1Q7c293Q3a1Q7c294Q3a50QQ_trksidZp3286Q2ec0Q2em14QQhashZitem230310166282QQitemZ230310166282QQptZMotorsQ5fAutomotiveQ5fTools

 

http://cgi.ebay.com/ebaymotors/SB-BB-CHEVY-ENGINE-RUN-TEST-STAND-PLANS-9-pg-FREE-S-H_W0QQcmdZViewItemQQ_trkparmsZ72Q3a1205Q7c66Q3a2Q7c65Q3a12Q7c39Q3a1Q7c240Q3a1318Q7c301Q3a1Q7c293Q3a1Q7c294Q3a50QQ_trksidZp3286Q2ec0Q2em14QQhashZitem320324798487QQitemZ320324798487QQptZMotorsQ5fAutomotiveQ5fTools

 

 

IF i was going to fabricate one ID start with this

 

http://www.northerntool.com/webapp/wcs/stores/servlet/product_6970_406688_406688

 

ID buy (2) 3 ft long, and (2) 5 ft long sections of 1.5"x 3" box steel too weld as a base,

and about 20 feet of 1" x 2" box steel as uprights for the gauges, and radiator,battery box, ETC. into. plus a section of 1/8" thick 1ft x 2 ft aluminum diamond plate to mount the gauges,

ID buy (4) of these wheels

 

http://www.northerntool.com/webapp/wcs/stores/servlet/product_6970_200337096_200337096

 

and find a decent radiator from a salvage yard, Id get these gauges

 

http://store.summitracing.com/partdetail.asp?autofilter=1&part=ATM%2D4337&N=700+115&autoview=sku

 

http://store.summitracing.com/partdetail.asp?autofilter=1&part=ATM%2D4327&N=700+115&autoview=sku

 

http://store.summitracing.com/partdetail.asp?autofilter=1&part=ATM%2D4391&N=700+115&autoview=sku

 

http://store.summitracing.com/partdetail.asp?autofilter=1&part=AVM%2D30%2D4100&N=700+115&autoview=sku

 

http://store.summitracing.com/partdetail.asp?autofilter=1&part=ATM%2D4498&N=700+115&autoview=sku

 

http://store.summitracing.com/partdetail.asp?autofilter=1&part=ATM%2D4301&N=700+115&autoview=sku

 

http://store.summitracing.com/partdetail.asp?autofilter=1&part=NEX%2D15512&N=700+115&autoview=sku

 

for UNDER about $750 and most of thats GAUGES you can have a decent engine stand built

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