Don`t mess with the voltage to the pump.Low voltage will kill an electrical device as quick as too high voltage.Regulate pressure with a regulator.Good luck.Have fun.Be safe.
Leo
Rough idle + pinging
- Thread starter thesameguy
- Start date
Don`t mess with the voltage to the pump.Low voltage will kill an electrical device as quick as too high voltage.Regulate pressure with a regulator.Good luck.Have fun.Be safe.
Leo
thesameguy
Famous Member
woodbutcher":32ajpp9t said:
Good luck.Have fun.Be safe.
Leo
*Too* low or high voltage will kill an electrical device, but especially on a car electricals are designed to operate within a range of voltages, usually 11-14v. Ford used resistors wires on fuel pumps for years, moving the effective voltage range for fuel pumps from ~12-14 to ~10-12 IIRC. I know all the turbo cars (Thunderbirds, Mustangs, XR4Tis, etc.) had them. I actually saved the resistor wire from my XR4Ti when I converted to a single in-tank pump as a curiosity. Mazda also used them on FB and I think FC RX7s to improve fuel economy by dropping pumps to a trickle at idle.
I am pretty sure how well this works would be a function of pump design... my Walbro 255lph ran fine for a couple hundred miles on the resistor'ed power before I had a chance to tear apart the wiring. A friend of mine let all the smoke out of his wires the first time he fired the car up after the same conversion. :shrug:
Edit: Looks like Mitsubishi used them on the 3000GT/Stealth too. I'm gonna email Federal-Mogul and Carter to see if I can use the same trick on their pump.
thesameguy
Famous Member
I am dredging this thread up *again*. 
I dedicated too much time in the Fall to installing a new front end kit (LCA, UCA, spring perches, various bushings), new wheel hardware (bearings, cylinders, drums, Moser studs), rehab'ing the parking brake, changing the diff fluid & pinion seal, doing the Shelby drop, some minor interior work, and installing a Summit (OEM'd Aeromotive) non-return fuel pressure regulator. It took a long time to hammer it all together, but last weekend I finally finished, got it aligned, and have been commuting in it this week. It's really been superb to drive!
I have fuel pressure set to 4psi, as indicated by the Autometer gauge installed on the FPR. It seems deadly reliable, which makes me happy. The "pinging" noise that originally started this thread is still present, but only for the first minute or two of driving in the morning when it's 40 degrees out. It never comes back during my 20-ish minute drive out, and not at all on my 25-ish minute ride home. I know exactly what the sound is now, and I don't know why I didn't think of it before: The car is running rich, unburned gas is getting into the exhaust manifold and igniting there. It sounded like it was coming from underneath because the sound was echoing down the exhaust pipe, possibly the combustion was being carried along in the exhaust stream. It's an anti-lag system, except I don't have a turbo.
What I have noticed by watching the A:F gauge (Autometer narrow band) is that hustling through traffic as best a 100hp automatic Falcon can the A:F is at the high end of stoich, and hangs out there no matter how hard I'm on the throttle. At a stop, it slowly creeps up from a few bars into rich to many bars into rich... and, the idle starts quite smooth but eventually becomes quite rough. Since I've actually been driving it in traffic, sitting around for 5 minutes at a time I get to watch this happen repeatedly. The process is slower/better if I've been rocketing through traffic, and faster/worse if I've been creeping along. My theory is that under lots of throttle the car is using fuel pretty completely, but creeping in D it's not and the bowl overfills.
Knowing nothing about carbs whatsoever, this sounds like what Frankenstang was talking about over the summer - a misadjusted float. Can anyone help an idiot out with proper adjustment on a Holley 1909? From some previous messing around, it seems the car has a little more power at 4.5psi fuel pressure than at the current 4.0psi, so I'd like to aim to run that if possible.
TIA!
I dedicated too much time in the Fall to installing a new front end kit (LCA, UCA, spring perches, various bushings), new wheel hardware (bearings, cylinders, drums, Moser studs), rehab'ing the parking brake, changing the diff fluid & pinion seal, doing the Shelby drop, some minor interior work, and installing a Summit (OEM'd Aeromotive) non-return fuel pressure regulator. It took a long time to hammer it all together, but last weekend I finally finished, got it aligned, and have been commuting in it this week. It's really been superb to drive!
I have fuel pressure set to 4psi, as indicated by the Autometer gauge installed on the FPR. It seems deadly reliable, which makes me happy. The "pinging" noise that originally started this thread is still present, but only for the first minute or two of driving in the morning when it's 40 degrees out. It never comes back during my 20-ish minute drive out, and not at all on my 25-ish minute ride home. I know exactly what the sound is now, and I don't know why I didn't think of it before: The car is running rich, unburned gas is getting into the exhaust manifold and igniting there. It sounded like it was coming from underneath because the sound was echoing down the exhaust pipe, possibly the combustion was being carried along in the exhaust stream. It's an anti-lag system, except I don't have a turbo.
What I have noticed by watching the A:F gauge (Autometer narrow band) is that hustling through traffic as best a 100hp automatic Falcon can the A:F is at the high end of stoich, and hangs out there no matter how hard I'm on the throttle. At a stop, it slowly creeps up from a few bars into rich to many bars into rich... and, the idle starts quite smooth but eventually becomes quite rough. Since I've actually been driving it in traffic, sitting around for 5 minutes at a time I get to watch this happen repeatedly. The process is slower/better if I've been rocketing through traffic, and faster/worse if I've been creeping along. My theory is that under lots of throttle the car is using fuel pretty completely, but creeping in D it's not and the bowl overfills.
Knowing nothing about carbs whatsoever, this sounds like what Frankenstang was talking about over the summer - a misadjusted float. Can anyone help an idiot out with proper adjustment on a Holley 1909? From some previous messing around, it seems the car has a little more power at 4.5psi fuel pressure than at the current 4.0psi, so I'd like to aim to run that if possible.
TIA!
Hello thesameguy,
Sounds like you've made some great strides on your car. It's amazing how some new suspension parts and maintenance can really breathe some fresh air into these older rides
Congrats 
As for the float setting, here is an image that may help for a rough reference on measuring the height relative to the carb housing (first diagram in upper LH corner, although this is on an 1100 so there will obviously be some differences betweent this and your 1909), but hopefully you're already familiar with your reference points and specs for your carb
:
When in doubt I'll error on the side of slightly leaner (lower float setting in bowl=higher end of float measurement spec).
Can't say I've heard of one being rich enough to cause 'pings' or mini-backfires in the ex manifold as your seem to describe...but there are always new ones on me. Your original sound clip, as I recall, still made me think of some type of 'mechanical' interference (metal to metal noise)...I need to re-listen. However as far as what you're seeing on your narrow band A/F...float setting seems like a definite possibility, if not idle mix setting (since it creeps more into the rich at stop). That's all I've got for now, but hopefully others might offer some fresh ideas...good luck
Sounds like you've made some great strides on your car. It's amazing how some new suspension parts and maintenance can really breathe some fresh air into these older rides
Congrats As for the float setting, here is an image that may help for a rough reference on measuring the height relative to the carb housing (first diagram in upper LH corner, although this is on an 1100 so there will obviously be some differences betweent this and your 1909), but hopefully you're already familiar with your reference points and specs for your carb
: 
When in doubt I'll error on the side of slightly leaner (lower float setting in bowl=higher end of float measurement spec).
Can't say I've heard of one being rich enough to cause 'pings' or mini-backfires in the ex manifold as your seem to describe...but there are always new ones on me. Your original sound clip, as I recall, still made me think of some type of 'mechanical' interference (metal to metal noise)...I need to re-listen. However as far as what you're seeing on your narrow band A/F...float setting seems like a definite possibility, if not idle mix setting (since it creeps more into the rich at stop). That's all I've got for now, but hopefully others might offer some fresh ideas...good luck
thesameguy
Famous Member
The idle mixture screw is at the bottom of its travel, and the car still runs quite rich. Someone above suggested the power valve leaking, but it's presumably a lot easier to mess with float settings than check the valve. Plus, the carb was rebuilt less than a few hundred miles ago, and I gotta believe they checked the valve. A float mis-setting seems way more likely.
Unfortunately I have no specs and no nothing on a 1909 - the only two carbs I've ever played with have been a CCC Quadrajet and an early '70s Nikki on a rotary Mazda.
So I've got nothing.
Unfortunately I have no specs and no nothing on a 1909 - the only two carbs I've ever played with have been a CCC Quadrajet and an early '70s Nikki on a rotary Mazda.
So I've got nothing.
1909 carb spec's
Carb. model----1909
Idle screw turns open---1 to 2 3/4
Float level dry-----5/16
bowl vent clearance---5/32
Idle------750 rpm(engine hot and screw on lowest step of cam)
choke unloader clearance---9/32
Dash pot clearance-----9/64
choke setting---On Index
pump setting---Seasonal setting holes in lever:long stroke for cold weather,short stroke for warm weather
Carb. model----1909
Idle screw turns open---1 to 2 3/4
Float level dry-----5/16
bowl vent clearance---5/32
Idle------750 rpm(engine hot and screw on lowest step of cam)
choke unloader clearance---9/32
Dash pot clearance-----9/64
choke setting---On Index
pump setting---Seasonal setting holes in lever:long stroke for cold weather,short stroke for warm weather
Hi Thesame guy.The backfiring in the exhaust system COULD mean a leak in the system somewhere allowing fresh air into the system causing ignition of unburned gasses in the pipes.Good luck.Have fun.Be safe.
Leo
thesameguy
Famous Member
Thanks guys.
I think I adjusted the float per the spec above (thanks Bubba!). The only way I know to adjust a float is flip the horn upside down and measure. Hope that's right. It was slightly off - perhaps 1/16" or so - but not serious.
Question about "idle screw" - I *assumed* that's the idle mixture screw, not the base idle screw, yeah? I hope so, because I went ahead and set it to exactly two full turns, then readjusted the idle speed to 750 with the car in Park. In Drive, that gets me an idle that hovers around 675/700 or so. If the idle is much higher, the transmission creep is pretty strong and it requires way too much pedal effort to keep the car still in traffic for long.
I regapped the plugs from .040 to .045 and cleaned them up. They're extremely new, but the rich running leaves them a little sooty. The car is running Pertronix and a Pertronix coil, and even at .045 there is great, clean spark.
No noise on startup afterwards, however, although it wasn't cold today. I'll see how it does when it's 35 degrees tomorrow morning.
It's still idling richer than I think it should... A:F at a stop is totally unchanged. Out on road, mixture hovers at the high end of stoich under normal throttle, and mid-stoich at full throttle. That seems a little richer than ideal, but healthy, and the car feels good on the road. That said, the idle is definitely smoother than it was and I think the car has a little more go. I surprised myself and a bicyclist that wanted to drag race on my test drive this afternoon. 
I filled the tank with 89 octane Chevron... I usually run 91 but I am wondering if maybe that's just more than the engine can use efficiently? No idea! But it's cold in Sacramento and even at full tilt with timing at 14 degrees there is no detonation.
I'm going to run it for a few days and see how it goes. I'm going to also get my compression tester back from my buddy and check compression. At this point, I think all the adjustments I can make are in spec so maybe I've just got a weak cylinder or something... I dunno. There's a 200/C4 on Craigslist in the Bay Area I'm really tempted to go pick up, but I'm not quite ready to throw in the towel on the original running gear yet.
Thanks guys!
PS, side note: The car handles WONDERFULLY with the new front end/KYBs/Shelby drop. On a particular onramp I take every day to work I used to get to the straight part before laying on the throttle, and getting up to freeway speed was a small challenge. The car is *really* confident feeling now, and I'm comfortably at 70 long before the merge lane ends. If I can get this running issue sorted, I'll feel really good about some aesthetic rehab! I joke about the car's lack of power, but truth be told there is nothing I'd change - it's really a great drive and I love the car.
I think I adjusted the float per the spec above (thanks Bubba!). The only way I know to adjust a float is flip the horn upside down and measure. Hope that's right. It was slightly off - perhaps 1/16" or so - but not serious.
Question about "idle screw" - I *assumed* that's the idle mixture screw, not the base idle screw, yeah? I hope so, because I went ahead and set it to exactly two full turns, then readjusted the idle speed to 750 with the car in Park. In Drive, that gets me an idle that hovers around 675/700 or so. If the idle is much higher, the transmission creep is pretty strong and it requires way too much pedal effort to keep the car still in traffic for long.
I regapped the plugs from .040 to .045 and cleaned them up. They're extremely new, but the rich running leaves them a little sooty. The car is running Pertronix and a Pertronix coil, and even at .045 there is great, clean spark.
No noise on startup afterwards, however, although it wasn't cold today. I'll see how it does when it's 35 degrees tomorrow morning.
It's still idling richer than I think it should... A:F at a stop is totally unchanged. Out on road, mixture hovers at the high end of stoich under normal throttle, and mid-stoich at full throttle. That seems a little richer than ideal, but healthy, and the car feels good on the road. That said, the idle is definitely smoother than it was and I think the car has a little more go. I surprised myself and a bicyclist that wanted to drag race on my test drive this afternoon. I filled the tank with 89 octane Chevron... I usually run 91 but I am wondering if maybe that's just more than the engine can use efficiently? No idea! But it's cold in Sacramento and even at full tilt with timing at 14 degrees there is no detonation.
I'm going to run it for a few days and see how it goes. I'm going to also get my compression tester back from my buddy and check compression. At this point, I think all the adjustments I can make are in spec so maybe I've just got a weak cylinder or something... I dunno. There's a 200/C4 on Craigslist in the Bay Area I'm really tempted to go pick up, but I'm not quite ready to throw in the towel on the original running gear yet.
Thanks guys!
PS, side note: The car handles WONDERFULLY with the new front end/KYBs/Shelby drop. On a particular onramp I take every day to work I used to get to the straight part before laying on the throttle, and getting up to freeway speed was a small challenge. The car is *really* confident feeling now, and I'm comfortably at 70 long before the merge lane ends. If I can get this running issue sorted, I'll feel really good about some aesthetic rehab! I joke about the car's lack of power, but truth be told there is nothing I'd change - it's really a great drive and I love the car.
Yes that is the idle mix screw.
On most carbs, the idle mixture screw (slotted, knurled, spring under it) and turning it is (IN=LEANER) and (OUT = RICHER). Before you even try setting the carb always set the points (if you have them still) to proper dwell and timing to spec.’s. All those tune up parts i.e. points, cap, rotor, wires etc. need to be in good condition
Once engine is warmed up good make sure the choke is fully open. Find the idle-stop screw; set the idle to as low as it will run reasonably. Then tweak the idle mixture screw for the fastest idle speed. If the idle is now "too fast", back off the idle-stop screw to slow it down, and reset until you get it at the highest idle. (An alternative method is to use a vacuum gauge, and adjust idle mixture for highest vacuum.) Then, turn the mixture screw in (LEAN) a tiny bit until you hear the idle speed drop "a bit", 50 rpm or so. It's about the smallest noticeable speed drop. (Alternatively, until vacuum drops 1 - 2 In Hg). That's called "lean idle drop". It's good for emissions and leaner idle is better than richer here. Than reset the idle RPM to spec in drive with parking brake set for an auto trans. With a stock or near stock motor it ought to be very smooth.
I think that if your getting creep in gear at a stop than 750 is still too high of an idle for your auto trans (converter) I would try 550 to 650 RPM in gear with park brake set engine should not be trying to move the car at idle. thesameguy
Famous Member
That is awesome info, thank you. I have always been confused about the proper way to set a carb - manuals invariably say something circular, set the timing correctly then set mixture then set the idle so you can set the timing. The car is fully Pertronix'ed, with new coil/cap/rotor/wires/plugs and base timing (vacuum plugged) at 14 degrees so the ignition system should be set. Vacuum is a strong 17 in when I last checked. I probably do need to check again now that I futzed with things.
I'll go through your steps. I have a tachometer on my timing light and a vacuum gauge, so I've got all the right tools. If I still can't lean out the mixture properly I'm going to have to assume there is something tragically wrong with the carb (although The Carburetor Factory didn't think so) or the engine itself. A compression test should answer that question.
The car is fully Pertronix'ed, with new coil/cap/rotor/wires/plugs and base timing (vacuum plugged) at 14 degrees so the ignition system should be set. Vacuum is a strong 17 in when I last checked. I probably do need to check again now that I futzed with things.I'll go through your steps. I have a tachometer on my timing light and a vacuum gauge, so I've got all the right tools. If I still can't lean out the mixture properly I'm going to have to assume there is something tragically wrong with the carb (although The Carburetor Factory didn't think so) or the engine itself. A compression test should answer that question.
AHHH!!!!!thesameguy":2aiqchj4 said:
sorry for some reason every time I run chevron it's ususally 2-3 points lower than advertised, I've found QT and shell to be more accurate on thier octain, and usually cheapper, or if at all possible use costco's gas, the actually measure the octain and if it's wrong they reimburse the people that bought that gas.
the way I would set the idle/timing, little different but same concept
raise idle high ~1200rpm, unplug distributor canister and plug vacuum line, using vacuum gauge on manifold vacuum, set timing for highest vacuum, then change the idle mixture for highest rpm, then lean it out slightly like bubba recommended. then plug the distrubutir vacuum lie back in, set idle around 900rpm (in park) then move distributor slightly to get get higher vacuum, 20 is is ideal but 19 is good. then place in drive with parking brake on and set idle to desired rpm.
then the next part, go find a hill and climb it in drive, listen for ping, if you have ping, retard timing 1-2* and bump up idle. repeat until no more ping. remember to try and keep max vacuum in any change. your LOM needs it.
i have found that to be the best way with my 1100v and LOM, I too used the pertronix setup
got 20-25mpg out of that setup, more than what I get with the 2bbl and DUI...thesameguy
Famous Member
I don't know how it is in other states, but in California the government routinely inspects gas stations to ensure they are selling what they are advertising and in the quantities they are charging for. A good friend of mine works for the company that sells some of this testing equipment to the state, so he has a bit of an inside line on fuel quality and pump metering accuracy. Chevron stations routinely do well in these spot-checks, whereas Shell recently paid a $110 million fine for false claims about their additive package. I feel pretty good about buying Chevron. Additionally, I have quite an inventory of boosted (like, turbo'd, not stolen ) cars in the garage and they let me know pretty quickly if their gas is not up to snuff. Since we only are allowed 91 octane gas in California, each one of those points is important when there is 20psi in the manifold. Chevron fuel has never let me down, and until it does I will keep buying it.
I'll give your method a try if Bubba's doesn't work out. I am *really* eager to know conclusively that this engine is viable, or already seen its best days.
) cars in the garage and they let me know pretty quickly if their gas is not up to snuff. Since we only are allowed 91 octane gas in California, each one of those points is important when there is 20psi in the manifold. Chevron fuel has never let me down, and until it does I will keep buying it.I'll give your method a try if Bubba's doesn't work out. I am *really* eager to know conclusively that this engine is viable, or already seen its best days.
thesameguy
Famous Member
Well, I feel like a dummy for this, but a broad lack of information about old motor and carbs led me on an Incorrect Path.
I spent a few hours yesterday trying both methods of setting the carb, but - without going into gory detail - I found it virtually impossible get the mixture, timing, and vacuum all to a satisfactory point at the same time. Further, no combination of things right and not quite right led to any real improvement in idle mixture or idle smoothness. The car is still quite good on the roadway - it'll do quite a bit over the speed limit comfortably, and never had a hard time keeping up with traffic.
That said, having two distinct methods of tried & trued methods for setting up the carb I ruled it out. I spent a little more time today cleaning up some fittings and whatnot, then hosed down the engine with carb cleaner to ensure I had no vacuum leaks. Until this point, I more or less assumed I didn't have any simply because vacuum leaks should lead to lean running far more readily than rich, but when you're grasping at straws... Anyway, found none. Engine is tight.
Finally - and something I should have done 18 months ago when I bought the bloody thing - I broke out my compression tester. Cyl 1, 0psi. Cyl 2, 0psi. Cyl 3, 0psi. That can't be right. The Shraeder valve in my tester failed. Replaced that. Cyl 1, 100psi. Cyl 2, 110psi. Cyl 3, 105psi. Cyl 4, 105psi. Cyl 5, 110psi. Cyl 6, 30psi. Crap.
I threw some oil in 6 and tried again - 60psi, then 45psi, then back to 30psi. Sounds like I am need of re-ringing #6.
I am *really* torn on this. I am pretty sure this is the original engine to the car, but I'm not sure I want to rebuild the 170. I'm really leaning towards going up to a 200 (if I can find one). I'm not putting in a V8 - but I am entertaining the idea of finding a wrecked four cylinder Ranger and putting in a 2.3l Duratec and 4R55 transmission. It's just... buying a wrecked Ranger would be done with money I don't have.
So... Any thoughts?
I spent a few hours yesterday trying both methods of setting the carb, but - without going into gory detail - I found it virtually impossible get the mixture, timing, and vacuum all to a satisfactory point at the same time. Further, no combination of things right and not quite right led to any real improvement in idle mixture or idle smoothness. The car is still quite good on the roadway - it'll do quite a bit over the speed limit comfortably, and never had a hard time keeping up with traffic.
That said, having two distinct methods of tried & trued methods for setting up the carb I ruled it out. I spent a little more time today cleaning up some fittings and whatnot, then hosed down the engine with carb cleaner to ensure I had no vacuum leaks. Until this point, I more or less assumed I didn't have any simply because vacuum leaks should lead to lean running far more readily than rich, but when you're grasping at straws... Anyway, found none. Engine is tight.
Finally - and something I should have done 18 months ago when I bought the bloody thing - I broke out my compression tester. Cyl 1, 0psi. Cyl 2, 0psi. Cyl 3, 0psi. That can't be right. The Shraeder valve in my tester failed. Replaced that. Cyl 1, 100psi. Cyl 2, 110psi. Cyl 3, 105psi. Cyl 4, 105psi. Cyl 5, 110psi. Cyl 6, 30psi. Crap.
I threw some oil in 6 and tried again - 60psi, then 45psi, then back to 30psi. Sounds like I am need of re-ringing #6.
I am *really* torn on this. I am pretty sure this is the original engine to the car, but I'm not sure I want to rebuild the 170. I'm really leaning towards going up to a 200 (if I can find one). I'm not putting in a V8 - but I am entertaining the idea of finding a wrecked four cylinder Ranger and putting in a 2.3l Duratec and 4R55 transmission. It's just... buying a wrecked Ranger would be done with money I don't have.
So... Any thoughts?
With it that low is probably a burnt valve rather than rings , pull the head and look , HOWEVER , you did say it was pinging , and again I stress a compatible dist curve for the application , Detonation is THE biggest killer of an otherwise healthy engine , No ones EARS can safely set ignition ( if that was so knock sensors would not of been invented / needed ) you need to know the curve , not its new so its OK , I didn't hear it ping , etc your dealing with 40+ year old parts , OR reman parts that the wearing pieces have been replaced , NOT CURVED FOR THE APP, and NEW Aftermarket Dist's also need checked and usually re-curved , there is no way for the MFG to know how you use your Vehicle. Money spent on a part does NOT Guarantee success , if that was so , the Space Shuttle would of never broken down or blew up , ( its the most expensive people mover of all time ) , and for the record I have always supported our Space Program and always will , so that was NOT a negative comment it was an analogy to the extreme.
thesameguy
Famous Member
Wouldn't a wet test increasing compression indicate a bottom end problem? How would oil in the cylinder affect a burnt valve?
Yes much of the time it dose. And a wet test will almost always raise compression some.
Depends on how bad the valve is burnt, a very loose guide will also cause this.
Because there is such a difference between the other cylinder readings I will have to X2 and agree with FSD on this that you will likely find your trouble in the head. But if it’s a very high mileage motor it would be 50 / 50 chance that it would still have ring seal with a fresh valve job might be wise to just get a re-ring kit not much more or else a total rebuild thesameguy
Famous Member
Who knows how old this motor is... I am virtually positive it's the original mill (it's all 1962-correct parts) so for all I know it could have a million miles on it.
#6 did 30 psi dry and 60p psi wet. I just don't see how oil poured into the cylinder could improve valve sealing - it just sits on the piston. Gaining 30psi with that oil being there is huge - I gotta believe that bump in compression is due to oil making up a seal where the compression rings weren't.
I think I may go pick up a leak down tester - always wanted to have one around, now I've got a reason to. That should help pinpoint the issue. OTOH, it probably doesn't matter. If I'm going to the trouble of rehab'ing this motor, it's gotta get a full rebuild. I'm not going to waste time fixing one thing only to have another thing break in a few months. The real question is whether to do anything with the 170 at all, or go hunt down a 200, or do something drastic (like a turbo DOHC inline five from a Volvo )
I have never actually rebuilt a motor solo - piles of top end work, lots of teardowns, but never put an entire one back together again. Could be a good learning experience. I'm just afraid it'll get away from me... lighter pistons, bigger cam, new valvetrain... BAM! $3000 120hp motor. DOH!
#6 did 30 psi dry and 60p psi wet. I just don't see how oil poured into the cylinder could improve valve sealing - it just sits on the piston. Gaining 30psi with that oil being there is huge - I gotta believe that bump in compression is due to oil making up a seal where the compression rings weren't.
I think I may go pick up a leak down tester - always wanted to have one around, now I've got a reason to. That should help pinpoint the issue. OTOH, it probably doesn't matter. If I'm going to the trouble of rehab'ing this motor, it's gotta get a full rebuild. I'm not going to waste time fixing one thing only to have another thing break in a few months. The real question is whether to do anything with the 170 at all, or go hunt down a 200, or do something drastic (like a turbo DOHC inline five from a Volvo
)I have never actually rebuilt a motor solo - piles of top end work, lots of teardowns, but never put an entire one back together again. Could be a good learning experience. I'm just afraid it'll get away from me... lighter pistons, bigger cam, new valvetrain... BAM! $3000 120hp motor. DOH!
...never put an entire one back together again. Could be a good learning experience. I'm just afraid it'll get away from me... lighter pistons, bigger cam, new valvetrain... BAM! $3000 120hp motor...
Youe experiences written B 4 this section show readness...
my 250 is $759 prts, $759 machinest rebuild costs,
I had 2 of those Wolwo motors (like U mention - I think they were 2.3s? from the early and mid 90s) and was not impressed. Not real durable (sure seemed quick tho). Now the earlier 4s were ("B" something model) impressive )4 me).
Youe experiences written B 4 this section show readness...
my 250 is $759 prts, $759 machinest rebuild costs,
I had 2 of those Wolwo motors (like U mention - I think they were 2.3s? from the early and mid 90s) and was not impressed. Not real durable (sure seemed quick tho). Now the earlier 4s were ("B" something model) impressive )4 me).
thesameguy":xlgwxsfs said:
IIWIYS...
find a local company to build a stock motor, supply the cam and timing chain set, supply no covers (valve covers, timing, oil, etc...) and don't give the valve train. they get it installed for really cheap if you want stock with a cam. get CI 2-1bbl adaptor, a weber progressive 2bbl, and with stock bottom end, cam and 2bbl adapted, you'll reach your 120hp at the rear tires. simple keep it simple it will respond.
if you want to go 200 route, make sure to port the valve bowls and if you ca go bigger valves.
my dyno guy has a quote, all scouts get scalped, be the pioneer for a change and keep it simple. anymore than that and you'll spend enough for a v8 conversion.
most long blocks will run 500-650 at a quick rebuild shop, if it's a speed shop yeah expect the 1400 range for that long block. and do your self a favor, degree your own cam
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