post me some questions

[twoeightyzx]

Hey grumpyvette, I have a fuel related question that I'm hoping you will be able to help me with. I did a bit of searching on here and have yet to find any posts that may help me. My '78 Z will start stumbling (sounds like small backfires) at random times. The worst of them being last night. I was doing 70 mph on the highway when it started to stumble. I slowly pressed the accelerator and the stumbling subsided. As I let off the accelerator to slow back down from roughly 74mph it started to stumble again. This time pressing the accelerator only caused it to stumble more and I was forced to pull over as it would not accelerate and once I stopped the car died. When I tried to start her back up it flooded the engine. After disconnecting the Fuel Pressure Regulator the Z fired up on the second crank of the ignition. I was able to drive home this way. Once before the car started to stumble upon starting, it was during this when I learned that pulling the vacume line off the Fuel Pressure Regulator would make the engine run correctly.

 

Things that I have replaced while tracking the cause of this problem:

 

New Fuel Pressure Regulator: changed prior to last night.

New Fuel Filter: located on the inner fender.

New Pre Fuel Pump Filter: between the tank and fuel pump.

 

Any and all help you and/or anyone can give me will be greatly appreciated.

[grumpyvette]

post a couple detailed pictures of your spark plug condition and PLEASE POST SOME ENGINE DATA,like, the intake/carb or injection system your useing, IT helps a bit to have some CLUE what IM working with???

Im going to assume its a EFI untill you say differant

 

have you adjusted the IAC and TPS and verified all the injectors are working correctly and the maf,mat,and coolant sensors are functioning correctly and theres no vacuum leaks?

[gvincent]

your link doesn,t work for me, but thats not critical at all, if you ask the supplier in most cases they will know if the hose, lines they supply are compatable with current fuel, and at what pressures,but keep in mind current fuels have a bit of alcohol in many of the blends and hose that handles gas may not handle an alcohol blend /gas fuel long term...I see guys experiance leaks from degraded rubber/synthetic fuel lines that held up fine with just gas, far more frequently with todays fuel lines than in the past

 

Thanks Grumpy,

I'll put a call into them.

The link was yours from post #112 above.

I am searching for a suitable inexpensive hose for FI use with -AN fittings

Thanks again,

Greg

[Xander]

yet another question for you. I have a 305 SBC with patriot (ebay) heads. and a super hurricane efi intake. The cam is a crane 10005 272 deg duration and 0.485 lift with 1.6 ratio roller rockers. I am running MS&S II extra. My trans is a borg warner t5. Diff ratio 3.54 OBX LSD. exhaust size is 2.5" from the block huggers merging to 3" behind the trans. I have a single 3" magnaflow muffler.

I guestimate about 300 hp. I ran a 8.66 1/8 mile @ 88mph. The car is running well but it is obvious I am lacking torque. I can buy a decently priced 1pc rear seal 350 SBC (4 bolt). The engine looks to be in good shape.

 

Can I obtain 400 rwhp with the 350 and the parts I already have?

 

Or should I go 383, new heads, intake and cam. If the engine indeed turns out to be a good one then it would be a shame not to use the bottom end. Can a stock bottom end handle 400 hp? I would probably need to swap in a hotter cam. I have no idea if the engine has roller lifters or not.

 

I could try to sell my old 305 engine as is. It is a lot easier to sell an engine that people can take for a drive. And spent the money on the new engine.

[grumpyvette]

to realistically expect 400hp youll be better off starting with the 383 vs the 350, while both engines can do it, the extra displacement and ease of building compression with your current heads, (or better ones) makes the 383 the better choice provided its in decent mechanical condition, and youll surely need a cam upgrade, now you didn,t post specs on the 383 short block and cpr but your best off begining the combo with about a 10:1 cpr if you expect to realistically reach 400hp. just keep in mind anything your can do with a 350 can usually be done more effectively with a 383, and a flat tappet solid lifter cam in the 240-245 durration and .500-.530 lift range, matched to a 10;1-11;1 cpr and a decent intake and heads is generally required to be sure youll get that 400 hp exceeded easily on a budget build, something thats not going to give great gas mileage or be particularly traffic friendly but it will kick butt over about 3500rpm-6500rpm

something like this crower with the 1.6:1 ratio rockers in that 383 should get you there!

 

http://www.crower.com/misc/cam_spec/cam_finder.php?part_num=00321&x=10&y=5

 

brouse thru these

 

http://rustpuppy.org/chp/

 

http://www.ryanscarpage.50megs.com/combos1.html

 

http://www.chevymania.com/dyno/

[jpdavis]

I got to thinking about old times while undoing all the stuff necessary to drop the engine out of my '97 Z28.

 

This is a carb and choke question. In my dune buggy I had to have the choke closed nearly halfway for the engine to run right. 2074cc with a Zenith 2bbl, a decent combo for back then. The carb iced up frequently and I just dealt with it.

 

10 years later I put an Edelbrock 600 on an AMC 360 and I had the same problem with my CJ7. The choke needed to be partially closed for the engine to run decent.

 

I am not a carb person and just took the easy way out but what was going on there? I can understand the ice due to venturi velocity with the VW but what was going on with restricting airflow with these engines?

 

Thanks, Jim.

[grumpyvette]

the (choke) is used to temporarily richen the f/a ratio, making the engine easier to start on cold conditions, restricting the flow rates , with the choke, typically increases the vacuum signal the venturies see and richens the effective f/a mixture ratio, as it tends to draw more fuel. if your running better with the choke partly closed richening the jets usually tends to solve that.

now obviously the type of jetting and the float settings, adding differant boosters, discharge nozzels,fuel pressure levels, accellerator pump settings,the type of carb, engine size, cam timing or other factors might come into this in some applications

 

 

 

http://www.2carpros.com/how_does_it_work/choke.htm

"Carburetor Choke Operation

A choke is used in conjunction with a carburetor. It is a valve that opens and closes and used to restrict air flow. The restriction enriches the fuel/air mixture to aid in the initial startup of the vehicle. The choke creates a stronger vacuum to pull more fuel from the jets and into the air/fuel mixture. When the engine warms up the choke slowly releases and stays in the wide open position."

 

 

 

 

http://www.carcraft.com/techarticles/116_0508_carburetor_showdown/index.html

 

IVE ("wasted" A ton OF CASH GAINING A GREAT DEAL OF EXPERIANCE)

I guess I would not know 1/100th of what I know without having done that though!:rofl:

[twoeightyzx]

Sorry for the delayed reply, life/school got in the way. My Z is running the stock fuel injection. Having read your response I remembered upping the IAc after changing the fuel pressure regulator. I did lower it again and today was the first day taking into town. So far no issues upon startup or driving. However it was 30-45 minutes of driving before it shut down on me previously.

[cannonball55]

Heya grumpy. I'm building a 1972 240z. So far I have purchased these parts. http://store.summitracing.com/partdetail.asp?autofilter=1&part=NAL%2D19171224&N=700+4294925232+115&autoview=sku

http://www.jegs.com/i/TCI/890/371000P1/10002/-1

R200 rearend unit the stock CLSD unit (bought some of those clutches that were cut by a member so will have 6 new clutches in it)

I have not started any of the conversion. Just getting everything purchased and ready. The car should weigh about 2400lbs. at the moment I hope to get it down to around 2100-2200lbs. What rear end gearing would you suggest? I do plan on flaring the rearend and running bigger tires. Maybe 10.5 cheaterslicks on weekends and something bit less sticky for the street. About same sized though. The gearing in it atm is 3.70:1. I was kinda leaning towards maybe 3.23 for better mpg and higher top end. Whats your thoughts on this? I want to keep the car streetable, but be able to get the blood pumping when i press the "Go pedal".

[grumpyvette]

if youve got a 3.73:1 rear gear now Id stay with that, as the swap to a 3.23 rear gear will hurt the low and mid rpm accelleration and youll rarely, if ever be able to use the upper speed potential, and the cost to swap is wasted money, Id put the largest tires I could fit on the car, and the tallest dia. when you tub the rear

your much better off maximizeing the accelleration in thw 0-100mph range vs worrying about the over 100mph accelleration

[cannonball55]

Thanks Grumpy. Really cool of you to take your time out to help everyone out like this.

Thanks,

Stewart

[jasper]

Hi Grumpy!

 

Your professional opinion and guidance would be appreciated.

 

I have a '77 280z 5spd coupe, 48k on the clock, no rust. Last saw daylight sometime in 1982.

 

I also happen to have a 1989, 350 TPI/700r4 Camaro setup. approx 60k.

 

A marriage has been arranged. Goats and chickens have been exchanged between various family members.

 

I plan on using the JTR parts and game plan. Most probably the 700r4 also.

 

I plan on resealing the engine prior to install. Open to mods at this time.

SUGGESTIONS?

 

700r4 vs 5?/6spd? PREFERENCE?

 

MAF vs speed density. I'm a bit ignorant on this subject/choice.

 

Diff ratio suggested??

 

The car will NOT be raced or auto crossed. But I may be guilty of abuse from time to time.

 

I'm looking for a nice, balanced package. I have NOS Bilsteins and springs on the shelf. I don't need 450 HP....Kind of hard to get it all to the ground and use it.

 

Thanks for your help/ advice/ expereince......Tommy

[grumpyvette]

Hi Grumpy!

 

Your professional opinion and guidance would be appreciated.

 

I have a '77 280z 5spd coupe, 48k on the clock, no rust. Last saw daylight sometime in 1982.

 

I also happen to have a 1989, 350 TPI/700r4 Camaro setup. approx 60k.

 

A marriage has been arranged. Goats and chickens have been exchanged between various family members.

 

I plan on using the JTR parts and game plan. Most probably the 700r4 also.

 

I plan on resealing the engine prior to install. Open to mods at this time.

SUGGESTIONS?

 

700r4 vs 5?/6spd? PREFERENCE? either of the manual trans choices allows far more flexiablity choices in engine components

 

MAF vs speed density. I'm a bit ignorant on this subject/choice.

MAF is generally easier to tune,for a basically stock or slightly modded combo, SPEED DENSITY has more range/flexibility

 

Diff ratio suggested?? depends on goals and engine combo. and wheel well size , but 3.54-4.11:1 is probable the best range,(tubbed or not) Ive always liked the 3.90:1 gears and 25-27" tires

 

The car will NOT be raced or auto crossed. But I may be guilty of abuse from time to time.

 

I'm looking for a nice, balanced package. I have NOS Bilsteins and springs on the shelf. I don't need 450 HP....Kind of hard to get it all to the ground and use it.

 

Thanks for your help/ advice/ expereince......Tommy

 

got a budget in mind? do you need to pass emmision testing? give me more info please

[memegtr]

ok....here is my Q

im going from a manual tranny to an automatic one in my z31

the engine is a vg30 NA

the new tranny is a E4n71B

because of the vg30 being manual trannsmission....

im havin trouble with the tor

[memegtr]

ok....here is my Q

im going from a manual tranny to an automatic one in my z31

the engine is a vg30 NA

the new tranny is a E4n71B

because of the vg30 being manual trannsmission before

im havin trouble installing the torque converter, because i dont think the plate will support it by itself...i guess i need some piece when going to the crankshaft.

thanx for any help

[Zfan1]

Grumpy,

 

Got myself in a bit of a pinch I think. I partially dropped a valve on my new AFR 210 heads, when I pulled the heads off the short block I found where I had been getting oil in the runners on the heads not to mention oil residue in the intake as well. The very bottom of the intake gaskets around the ports appeared to be leaking / not sealing.

 

I had the heads milled .010 and the block itself is zero decked. My machinist said it could be the intake isn't seating now and needs to be milled. He said to drop it in the valley between the heads and if the bolts hang up when threading the intake bolts in it will probably need to be milled .060.

 

I put the intake on and checked the intake bolts and they lined up just fine so I put the motor back together. Low and behold the motor is smoking at idle and using oil again. I am also having issues with possible blow by already.

 

I figured I would run a compression test this week to see if the rings just never really seated. As far as the intake is concerned I am scratching my head. Th intake seats both front and back and the bolt holes on the intake line up with the holes in the heads. Could it just be warped?

 

Any input you may have would be appreciated as I just freshened the motor up in march of 08. Maybe the rings never got seated correctly.

 

Thanks,

Mike

[grumpyvette]

Thats a very comon problem, with heads that have been milled (especially angle milled) or on a block thats been decked, the cheap and dirty fix is just use extra thick or thinner intake gaskets, (not the correct fix)the correct fix is to get the heads or intake machined to match each other correctly again.

As the deck is milled or the heads are milled the distance between the two heads intake gasket surface changes and that requires the intake generally to be machined to match the distance and angle.

Since you can,t cut things too a larger dimension, that generally means the heads have moved closer to the crank center line, and the intake is now too wide to seal correctly, as the block rails now tend to hit, before the effective clamp force, and alignment on the intake gasket around the ports is reached.

Because the heads are now just a bit closer together than on a stock engine configuration.

Your best bet is to install the intake without gaskets and take very precise measurements of the gap between the heads and intake face on both sides, of the intake/head gap, with the intake ends sitting on the block rails, and give that info to the machine shop. So they can correctly match the intake to the heads or machine the heads to match the intake.

YOUR almost certainly going to require the intake block rail area to be machined to allow the intake to sit deeper between the heads before it contacts the block rails.

[Zfan1]

Grumpy,

 

Thanks for the quick reply. What would you recommend using to gauge/measure the space between the intake and head, a feeler gauge?

 

I hate to think I just wasted 150.00 on a set of Felpro mls head gaskets if I have to tear her apart because the rings didn't seal properly but I guess until I do a compression test I will not really know.

 

I really don't know what else it could be because when I hammer the gas or make a run down the track I have oil on the valve covers, in the pcv valve line and breather which points to major blow by.

 

Thanks,

Mike

[grumpyvette]

a feeler gauge should work just fine, measure under the intake too block rail on both ends of the block,IF theres space, then center the intake between the heads,and measure all 4 corners of the intake gasket mateing surface, carefully if theres space, if the intakes sitting up off the heads because the block rail mounting surface touches instead of having room for sealant

[G-rib-73-240z]

hey grumpyvette, i had a thought about a day or so ago. Would it be hard to take the intake manifold off a LT1 and put it on a gen I 350 block? and make it fuel injected or is that a total not ganna happin?

 

(basicly would it bolt up or not even be close kinda like

 

ok i got one for you. LS1 heads on a 73 block? is it possible/would there be any gains (or loss') besides less weight?

differant engine families, it won,t interchange, without an incrediable amount of expensive machine work

 

that idea?

 

just a thought i had, still reading those books by the way, things in my household are getting crazy harder to have time to sit and read.

 

thanks again for all the help youve been so far, and all the knowledge youve passed on to us here

 

Thomas