Holley Help
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- simontwithers
- Newbie
- Posts: 29
- Joined: Thu Jul 31, 2008 9:44 pm
- Location: Leicester UK
Holley Help
I have an 3.5 SD1 engine with a kent 200 cam and Holley 4160 390cfm vac secondaries on a offy 360 inlet manifold.
It is a family engine used by my father 15 years ago. It was rebuilt back then with a hone, rings, crank grind etc. It only did 2000 miles in a Chevrolet before being pulled out and dry stored.
I pulled it from storage 2 years ago and freshened it up with a carb rebuild kit, replacement dizzy, new rotor, cap, leads, plugs, facet silver fuel pump. And installed it into my 1967 landrover series 2a.
The 1st MOT day went great and it was time to hit the road.
Major disappointment............ The engine lacked any torque and was no better than the 60 HP engine it replaced.
Since then (2 years) i have been chasing this problem round and round. The carb has had every combination of secondary vac springs, acc pump cams / squirters, idle settings, going.
The timing has been tried from the standard 6 to 14 degrees.
Its been on a Kripton tune where the leads were identified as dud, but gave little improvement.
In the end i tore it down, honed it, re-rung it, new big ends, new cam chain, skimmed the heads, set the lifter preload (30 to 60 thou) and checked the cam timing. To my delight i found the cam was timed 20 degrees late so i corrected this, and put it back together, porting the heads to stage 1 in the process.
I couldn't wait to drive the new more powerful engine..... WRONG !
still no torque. The engine is just the same. The only difference is the exhaust note, which has now doubled in volume and is popping on over run. I spent this last weekend going through the carb again with no results.
I know it will take sometime to bed the rings in, but this is more than that, it cannot manage small climbs in top gear (4th) and because the pedal is always on the floor its drinking fuel. Although there is no smoke from the exhaust.
The engine is like new inside, there was no wear on the bores at all. Im tearing my hair out. There is nothing like spending your hard earned cash with no results.
Im now out of ideas.
Now i've gave the sob story, i am asking if anyone has a known 390 Holley which i could borrow to drop on and try. I want to disprove the carb. I am happy to pay postage both ways and leave a deposit to its full value plus a rental fee.
All the rover v8 specialists i have rang want just the engine to put it on the dyno, but i cant face taking it out again. 2 years on, loads of money spent and nothing back !
Any input would be greatly apreciated.
Kind regards
Simon
It is a family engine used by my father 15 years ago. It was rebuilt back then with a hone, rings, crank grind etc. It only did 2000 miles in a Chevrolet before being pulled out and dry stored.
I pulled it from storage 2 years ago and freshened it up with a carb rebuild kit, replacement dizzy, new rotor, cap, leads, plugs, facet silver fuel pump. And installed it into my 1967 landrover series 2a.
The 1st MOT day went great and it was time to hit the road.
Major disappointment............ The engine lacked any torque and was no better than the 60 HP engine it replaced.
Since then (2 years) i have been chasing this problem round and round. The carb has had every combination of secondary vac springs, acc pump cams / squirters, idle settings, going.
The timing has been tried from the standard 6 to 14 degrees.
Its been on a Kripton tune where the leads were identified as dud, but gave little improvement.
In the end i tore it down, honed it, re-rung it, new big ends, new cam chain, skimmed the heads, set the lifter preload (30 to 60 thou) and checked the cam timing. To my delight i found the cam was timed 20 degrees late so i corrected this, and put it back together, porting the heads to stage 1 in the process.
I couldn't wait to drive the new more powerful engine..... WRONG !
still no torque. The engine is just the same. The only difference is the exhaust note, which has now doubled in volume and is popping on over run. I spent this last weekend going through the carb again with no results.
I know it will take sometime to bed the rings in, but this is more than that, it cannot manage small climbs in top gear (4th) and because the pedal is always on the floor its drinking fuel. Although there is no smoke from the exhaust.
The engine is like new inside, there was no wear on the bores at all. Im tearing my hair out. There is nothing like spending your hard earned cash with no results.
Im now out of ideas.
Now i've gave the sob story, i am asking if anyone has a known 390 Holley which i could borrow to drop on and try. I want to disprove the carb. I am happy to pay postage both ways and leave a deposit to its full value plus a rental fee.
All the rover v8 specialists i have rang want just the engine to put it on the dyno, but i cant face taking it out again. 2 years on, loads of money spent and nothing back !
Any input would be greatly apreciated.
Kind regards
Simon
- topcatcustom
- Forum Contributor
- Posts: 2965
- Joined: Sat Aug 09, 2008 11:53 am
- Location: Essex
- Contact:
During the rebuild did you check the cam itself? I take it you have checked for air leaks on the inlet or a carb port not capped etc, I suggest you pop your location in your details boxy thing- it may help as someone may be just up the road from you! As 5000SE suggested- taking it to the rollers may be well worth it, if they find a problem and fix it in 30mins it may only cost you £20odd !
TC
As Tom say's!!
Tell us where you are so the local lads might be able to help??
Even a lame 3500 smoker will make 100 horses if the bits are all set up ok !
Tell us where you are so the local lads might be able to help??
Even a lame 3500 smoker will make 100 horses if the bits are all set up ok !
Perry Stephenson
MGB GT + Rover V8
9.62 @ 137.37mph
Now looking for 8 seconds with a SBC engine
- simontwithers
- Newbie
- Posts: 29
- Joined: Thu Jul 31, 2008 9:44 pm
- Location: Leicester UK
thanks for all of your help so far.
I am based in leicester.
I measured the timing, lift and duration of the cam. All were very close to the data sheet. the lowest inlet was 0.18mm down and the lowest exhaust was 0.21mm down on spec
the inlet duration was 266 (should be 270) and exhaust 280 (should be 282)
I timed the cam with max lift on the inlet at 112 degrees after tbc (firing stroke).
The only rolling road i know of is operated by monkeys. I really need a V8 specialist with Holley carb knowledge.
I have checked for vac leaks.
Carb settings are 1.5 on idle mixture. 1/4 turn on secondary idle stop, i've tried every secondary vac spring, every acc pump cam, bigger nozzles, with some (but very very little) improvement.
The idle mixture screws make no difference on idle vacuum (14 hg max). The primary idle setting is such that the transfer slots in the bore are not exposed (this can make idle screws un responsive). I've tried different power valves as well. Float levels are set correctly.
Im suspect of the idle mixture screws not raising the idle vacuum. But i can stall the engine by winding them in.
Any questions please ask, and help me solve this problem.
Thank you for all your suggestions so far.
I will also try to get another dizzy to dis prove that, although i mapped the centrifugal advance with a strobe, and it matches the haynes through the rev range.
I could really do with a good holley to drop on.
I am based in leicester.
I measured the timing, lift and duration of the cam. All were very close to the data sheet. the lowest inlet was 0.18mm down and the lowest exhaust was 0.21mm down on spec
the inlet duration was 266 (should be 270) and exhaust 280 (should be 282)
I timed the cam with max lift on the inlet at 112 degrees after tbc (firing stroke).
The only rolling road i know of is operated by monkeys. I really need a V8 specialist with Holley carb knowledge.
I have checked for vac leaks.
Carb settings are 1.5 on idle mixture. 1/4 turn on secondary idle stop, i've tried every secondary vac spring, every acc pump cam, bigger nozzles, with some (but very very little) improvement.
The idle mixture screws make no difference on idle vacuum (14 hg max). The primary idle setting is such that the transfer slots in the bore are not exposed (this can make idle screws un responsive). I've tried different power valves as well. Float levels are set correctly.
Im suspect of the idle mixture screws not raising the idle vacuum. But i can stall the engine by winding them in.
Any questions please ask, and help me solve this problem.
Thank you for all your suggestions so far.
I will also try to get another dizzy to dis prove that, although i mapped the centrifugal advance with a strobe, and it matches the haynes through the rev range.
I could really do with a good holley to drop on.
- topcatcustom
- Forum Contributor
- Posts: 2965
- Joined: Sat Aug 09, 2008 11:53 am
- Location: Essex
- Contact:
The only thing you haven't (I think) mentioned so far is how good a spark you are getting, though it's one of the most obvious thing to check so I'm sure it is fine. Certainly sounds like the carb must be the culprit as it is the only thing you can't check very well. After owning an Edelbrock I'd promote it without a doubt, but you must be sick of spending money on this engine without knowing if it will actually do anything!
The other thing that further points to the carb is that Holley stuff doesn't always work right when you take it out of the box, let alone try it after been sitting for 15 years...
The other thing that further points to the carb is that Holley stuff doesn't always work right when you take it out of the box, let alone try it after been sitting for 15 years...
TC
- simontwithers
- Newbie
- Posts: 29
- Joined: Thu Jul 31, 2008 9:44 pm
- Location: Leicester UK
thanks Topcat.
The Occiloscope on the kripton tune initially showed my spark voltage to be of the scale. The leads showed open circuit. This was due to me fighting to get the boots on the 'cut to length leads' and breaking them.
After replacing them, the spark voltage came down to a sensible level (30 kv if i remember correctly - not positive though).
I appreciate all the input.
If it wasn't for all the money i've spent, i would have got rid by now, but i've spent more than i'll ever get back and i just want some fun out of it.
i am not new to building engines. I built a hot lump from all new parts for my 1967 beetle. A 1914cc engine that was torquey as hell on the street, revved like you wouldn't believe and ran 14's with a sniff of gas. Not bad for a full weight street car.
I got 3 years of fun before i sold it for a sensible car. Now i get to have a toy again, and this happens. Im starting to loose interest rapidly.
before this months rebuild the plugs were always a perfect tan brown when pulled after a long run. Im pretty sure this means my main jets are ok. I've checked all of the enrichment system for the power valve is clear as well ???
if i could prove it was the holley, i'd by a new one. But dont want to get stuck with £300 worth of carb i dont need.
The Occiloscope on the kripton tune initially showed my spark voltage to be of the scale. The leads showed open circuit. This was due to me fighting to get the boots on the 'cut to length leads' and breaking them.
After replacing them, the spark voltage came down to a sensible level (30 kv if i remember correctly - not positive though).
I appreciate all the input.
If it wasn't for all the money i've spent, i would have got rid by now, but i've spent more than i'll ever get back and i just want some fun out of it.
i am not new to building engines. I built a hot lump from all new parts for my 1967 beetle. A 1914cc engine that was torquey as hell on the street, revved like you wouldn't believe and ran 14's with a sniff of gas. Not bad for a full weight street car.
I got 3 years of fun before i sold it for a sensible car. Now i get to have a toy again, and this happens. Im starting to loose interest rapidly.
before this months rebuild the plugs were always a perfect tan brown when pulled after a long run. Im pretty sure this means my main jets are ok. I've checked all of the enrichment system for the power valve is clear as well ???
if i could prove it was the holley, i'd by a new one. But dont want to get stuck with £300 worth of carb i dont need.
There's no turning back now, I've finished being nice with this engine.
I'm only an hour down the road in Milton Keynes.
I dont know your engine, and I'm not up to speed on the holley 390 vac but here goes:
What rating power valve do you have fitted?? ie what vacuum rating?
Can you tell me the carb model number so I can look up the holley diagram. Unless you have one??
Are you sure the power valve works?
Have you measured manifold vacuum from idle to high rpm to see if the power valve suits the engine?
Did you set the carb up yourself?
And the old faves:
Compression test
Leakdown test
Fuel pressure
Fuel flow rate check
Dissy mech advance check with vac line off, from idle to 3000rpm
Dissy vac advance check at idle?
Regards
Perry
I dont know your engine, and I'm not up to speed on the holley 390 vac but here goes:
What rating power valve do you have fitted?? ie what vacuum rating?
Can you tell me the carb model number so I can look up the holley diagram. Unless you have one??
Are you sure the power valve works?
Have you measured manifold vacuum from idle to high rpm to see if the power valve suits the engine?
Did you set the carb up yourself?
And the old faves:
Compression test
Leakdown test
Fuel pressure
Fuel flow rate check
Dissy mech advance check with vac line off, from idle to 3000rpm
Dissy vac advance check at idle?
Regards
Perry
Perry Stephenson
MGB GT + Rover V8
9.62 @ 137.37mph
Now looking for 8 seconds with a SBC engine
- simontwithers
- Newbie
- Posts: 29
- Joined: Thu Jul 31, 2008 9:44 pm
- Location: Leicester UK
Thank you Perry
What rating power valve do you have fitted?? ie what vacuum rating? - a standard 6.5 as recommend by holley for mild engines although i have tried a 5.
Can you tell me the carb model number so I can look up the holley diagram. Unless you have one?? - carb is a 4160 i have a diagram on file
Have you sucked on the power valve to make sure it works? - i have sucked on the power valve itself and is ok when out of the carb.
Have you measured manifold vacuum from idle to high rpm to see if the power valve suits the engine? - been for a drive with a vac gauge, drops from 14 to nothing at full throttle so the power valve should be opening unless something un obvious is wrong internally.
And the old faves:
Compression test - was low before rebuild from 125 - 150 only just put rings in so wont show much right now.
Leakdown test - on cylinders or waterways ? the heads were skimmed with new gaskets on rebuild - tried a cylinder leakdown test but not really successful due to method
Fuel pressure - 3.5 at idle - need to check on a run although normally a car will go well on float bowl fuel before running out of fuel - will test this though.
Fuel flow rate check - i could try this into a measuring jug
Dissy mech advance check with vac line off, from idle to 3000rpm - checked ok
Dissy vac advance check at idle? - pretty sure i checked this, but i will check again to be sure. I can see dizzy moving when i suck on diaphragm.
i rebuilt and set the carb myself using a holley book / dvd / website / forums
I've tried the vac advance line on the timed vac port on the holley and on a full vac port and even tried with it disconnected
Thanks for all your help, I dont mean to dismiss anyones ideas and really appreciate the help, but this problem is proving tricky to find.
I will try fuel pressure / vac advance
What rating power valve do you have fitted?? ie what vacuum rating? - a standard 6.5 as recommend by holley for mild engines although i have tried a 5.
Can you tell me the carb model number so I can look up the holley diagram. Unless you have one?? - carb is a 4160 i have a diagram on file
Have you sucked on the power valve to make sure it works? - i have sucked on the power valve itself and is ok when out of the carb.
Have you measured manifold vacuum from idle to high rpm to see if the power valve suits the engine? - been for a drive with a vac gauge, drops from 14 to nothing at full throttle so the power valve should be opening unless something un obvious is wrong internally.
And the old faves:
Compression test - was low before rebuild from 125 - 150 only just put rings in so wont show much right now.
Leakdown test - on cylinders or waterways ? the heads were skimmed with new gaskets on rebuild - tried a cylinder leakdown test but not really successful due to method
Fuel pressure - 3.5 at idle - need to check on a run although normally a car will go well on float bowl fuel before running out of fuel - will test this though.
Fuel flow rate check - i could try this into a measuring jug
Dissy mech advance check with vac line off, from idle to 3000rpm - checked ok
Dissy vac advance check at idle? - pretty sure i checked this, but i will check again to be sure. I can see dizzy moving when i suck on diaphragm.
i rebuilt and set the carb myself using a holley book / dvd / website / forums
I've tried the vac advance line on the timed vac port on the holley and on a full vac port and even tried with it disconnected
Thanks for all your help, I dont mean to dismiss anyones ideas and really appreciate the help, but this problem is proving tricky to find.
I will try fuel pressure / vac advance
There's no turning back now, I've finished being nice with this engine.
- simontwithers
- Newbie
- Posts: 29
- Joined: Thu Jul 31, 2008 9:44 pm
- Location: Leicester UK
Another thought!!
How do you check for correct operaton of the secondary vacuum module. I assume if the diaphragm is shot or the springs is wrong it wont open and give any fuel?
How do you check for correct operaton of the secondary vacuum module. I assume if the diaphragm is shot or the springs is wrong it wont open and give any fuel?
Perry Stephenson
MGB GT + Rover V8
9.62 @ 137.37mph
Now looking for 8 seconds with a SBC engine
You use the paperclip test.......
You put a paper clip or similar on the Diaphragm to butterfly actuating arm at the top, as the chokes open the clip is moved down the arm and shows the extent that they have opened.
Or a blob of white grease at the top and see how far down it gets smeared
Andrew
You put a paper clip or similar on the Diaphragm to butterfly actuating arm at the top, as the chokes open the clip is moved down the arm and shows the extent that they have opened.
Or a blob of white grease at the top and see how far down it gets smeared
Andrew
4.5L V8 Ginetta G27