New engine will not run smooth
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New engine will not run smooth
You may have seen my other thread trying to figure out what my engine was built from.
Well its in now and it wont run smooth at all !
Brief history-
The engine was built in the US -(im in uk) about 4 yrs ago i think.
It was built by someone call Wild Bill allegedly.
It was stored well and all sealed up - there was no corrosion on the bores and it was well lubed with assembly paste and turned over easily by hand.
Spec AFAIK is a follows -
350 block overbored 30 thou with standard 350 crank
Edelbrock 6089 ally heads with a bit of port matching
Camshaft complete unknown but the engine is supposed to be appx 500 hp so guess it may be a bit wild ?
New 600cfm Holley -brand new from the box
New Moroso leads
New plugs
New distributor, cap and coil
Timing cover has aftermarket timing tab
Harmonic Balancer is 8" 'ProStreet' brand new
It has 15/40 mineral oil in for the break in
Ok then -
Got it to start up first turn
It wont run smooth and sounds like its knocking
It spits and coughs a bit but managed to get it to run for 30 mins break in vary the rpm between 2000-3000
It now starts fine but when its warm it runs on ( I think you call it dieseling?)
When you turn the key off it carried on running and spits and coughs.
It gets up to temp fine and the thermostat opens and fans kick in and out.
The problem is timing - whatever i try does not seem to work!
I advance it to get it starting smooth and try to tune it by ear but all it does once warm is run on.
The timing light show about 15-18 degress with vac disconnected and plugged @ about 900-1000rpm
But it runs so rough and lumpy knocking and banging.
The oil pressure is about 10 or just under at 1000 rpm and rises to about 30 at around 3000rpm so a bit low i guess but at least it has pressure. There were no markings on the pump so i have no idea what it is.
I am going to try another set of plugs (bosch BR9dc) in it tomorrow to see if the plugs are getting to hot - cant remember what is in there at the moment.
Anyone have any ideas i can try or stuff i can check?
Well its in now and it wont run smooth at all !
Brief history-
The engine was built in the US -(im in uk) about 4 yrs ago i think.
It was built by someone call Wild Bill allegedly.
It was stored well and all sealed up - there was no corrosion on the bores and it was well lubed with assembly paste and turned over easily by hand.
Spec AFAIK is a follows -
350 block overbored 30 thou with standard 350 crank
Edelbrock 6089 ally heads with a bit of port matching
Camshaft complete unknown but the engine is supposed to be appx 500 hp so guess it may be a bit wild ?
New 600cfm Holley -brand new from the box
New Moroso leads
New plugs
New distributor, cap and coil
Timing cover has aftermarket timing tab
Harmonic Balancer is 8" 'ProStreet' brand new
It has 15/40 mineral oil in for the break in
Ok then -
Got it to start up first turn
It wont run smooth and sounds like its knocking
It spits and coughs a bit but managed to get it to run for 30 mins break in vary the rpm between 2000-3000
It now starts fine but when its warm it runs on ( I think you call it dieseling?)
When you turn the key off it carried on running and spits and coughs.
It gets up to temp fine and the thermostat opens and fans kick in and out.
The problem is timing - whatever i try does not seem to work!
I advance it to get it starting smooth and try to tune it by ear but all it does once warm is run on.
The timing light show about 15-18 degress with vac disconnected and plugged @ about 900-1000rpm
But it runs so rough and lumpy knocking and banging.
The oil pressure is about 10 or just under at 1000 rpm and rises to about 30 at around 3000rpm so a bit low i guess but at least it has pressure. There were no markings on the pump so i have no idea what it is.
I am going to try another set of plugs (bosch BR9dc) in it tomorrow to see if the plugs are getting to hot - cant remember what is in there at the moment.
Anyone have any ideas i can try or stuff i can check?
#2
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Car: 1991 Trans Am GTA
Engine: 350 carbed
Transmission: T5
Axle/Gears: 7.5 10 bolt 4.10
Re: New engine will not run smooth
Sounds like you have an issue with timing. Could be a problem depending on how the person installed the timing chain. He could have advanced the timing by the timing gears. Some timing sets have 3 keyway notches on the gear
#3
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Car: 1991 Trans Am GTA
Engine: 350 carbed
Transmission: T5
Axle/Gears: 7.5 10 bolt 4.10
Re: New engine will not run smooth
Get #1 up on TDC On the compression stroke and see where the timing mark is sitting. Should be dead on 0 on the timing tab
#5
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Re: New engine will not run smooth
heres a good video on ignition timing.
perhaps your fuel mixture is off also? a high idle will cause run-on too. try turning the engine off in gear, that will usually help prevent the deiseling.
perhaps your fuel mixture is off also? a high idle will cause run-on too. try turning the engine off in gear, that will usually help prevent the deiseling.
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Re: New engine will not run smooth
I tried playing with the idle mixture screws and it does not seem to make it run any better.
So I am sure it must be ignition related.
I forgot i have also tried a different distributor, cap, coil and leads and no difference.
So I am sure it must be ignition related.
I forgot i have also tried a different distributor, cap, coil and leads and no difference.
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#9
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Re: New engine will not run smooth
Just pulled the spark plugs and looks like most of them have been hit !
Gapped them all when they went in and only 2 look ok now - ignore the colour !!!
Is there a short plug?
What would the engine builder have done to create this problem or is it something else?
Gapped them all when they went in and only 2 look ok now - ignore the colour !!!
Is there a short plug?
What would the engine builder have done to create this problem or is it something else?
#10
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Re: New engine will not run smooth
You can't set timing at idle sometimes with too large of a cam. The idle may surge too much and act too eratic.Try getting it close enough to rev up, hold the throttle open a bit and using a timing light with an advance wheel and set the max advance.
Might also make sure that aftermarket timing tab if it's adjustable is actually set to TDC properly.
Looking at your plugs though, you definitely have a dead hole, or eight! And wtf is up with those plugs!? If your plugs look like that, I would tear down and inspect the entire motor. Sounds like you got ripped off. If your plugs are that mucked up, I can't imagine the build quality (or lack there of) that went into the rest of this motor. This motor is fubar.
600cfm carb and 500hp...That's also a big negative.
Might also make sure that aftermarket timing tab if it's adjustable is actually set to TDC properly.
Looking at your plugs though, you definitely have a dead hole, or eight! And wtf is up with those plugs!? If your plugs look like that, I would tear down and inspect the entire motor. Sounds like you got ripped off. If your plugs are that mucked up, I can't imagine the build quality (or lack there of) that went into the rest of this motor. This motor is fubar.
600cfm carb and 500hp...That's also a big negative.
Last edited by Anti-Venom; 01-13-2013 at 07:59 AM.
#11
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Re: New engine will not run smooth
ouch! what plugs are you running now? what style pistons do you have?
#12
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Re: New engine will not run smooth
heres the suggested plugs for your heads from summits site.
http://www.summitracing.com/parts/ngk-7938/overview/
IIRC, ngk plugs go the opposite numbers for heat range. a bigger number is a colder plug.
http://www.summitracing.com/parts/ngk-7938/overview/
IIRC, ngk plugs go the opposite numbers for heat range. a bigger number is a colder plug.
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Re: New engine will not run smooth
I think the colour is just from the rough running.
Just fitted a set of Bosch plugs BR9DC i think with a copper washer under the standard washer to check if it is a clearance problem.
The plugs dont have any impact marks on them so it must be a slight touch if thats what it is?
Its fired up and idleing smooth at the moment - not given it any revs etc but need to move 3 cars out the shop to try to set it up/
Back soon i hope !
Just fitted a set of Bosch plugs BR9DC i think with a copper washer under the standard washer to check if it is a clearance problem.
The plugs dont have any impact marks on them so it must be a slight touch if thats what it is?
Its fired up and idleing smooth at the moment - not given it any revs etc but need to move 3 cars out the shop to try to set it up/
Back soon i hope !
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Re: New engine will not run smooth
heres the suggested plugs for your heads from summits site.
http://www.summitracing.com/parts/ngk-7938/overview/
IIRC, ngk plugs go the opposite numbers for heat range. a bigger number is a colder plug.
http://www.summitracing.com/parts/ngk-7938/overview/
IIRC, ngk plugs go the opposite numbers for heat range. a bigger number is a colder plug.
hopefully the copper washer should prove the issue.....
#15
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Re: New engine will not run smooth
In all seriousness. If you were lied too that this is worthy of 500hp and you just pulled out plugs that look like that. STOP! New plugs are the least of your concerns.
You need to thoroughly inspect this entire motor before going forwards, or else you may just end up with scrap metal.
You need to thoroughly inspect this entire motor before going forwards, or else you may just end up with scrap metal.
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Car: 1991 Trans Am GTA
Engine: 350 carbed
Transmission: T5
Axle/Gears: 7.5 10 bolt 4.10
Re: New engine will not run smooth
Take the plugs and find some shorter ones. It doesn't look like they would have been hit hard enough to cause serious damage because the porcelain is not even broke off the plugs. Just go to a local part store and have them get you the next size shorter plug. The block could have been zero decked at the rebuild and causing the plugs to be too close to the pistons especially if they aren't flat top pistons. Don't go ripping the engine apart just yet
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Car: 1991 Trans Am GTA
Engine: 350 carbed
Transmission: T5
Axle/Gears: 7.5 10 bolt 4.10
Re: New engine will not run smooth
Metal shaved off+long reach plugs+pistons= smashed spark plugs. It's only caused by a clearance issue. The plugs are just too long
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Re: New engine will not run smooth
Its running much better with copper washers under the new plugs.
Ill try to track down some shorter ones next week.
The timing set up fine with 34 total and about 12 static but now its really warm it just runs on when you shut it down.
Had enough for today so will try again tomorrow - just dont understand why the running on occurs and to make matters worse the idle speed has jumped up now is good and warm !
Just dont seem to get a break with this engine
Ill try to track down some shorter ones next week.
The timing set up fine with 34 total and about 12 static but now its really warm it just runs on when you shut it down.
Had enough for today so will try again tomorrow - just dont understand why the running on occurs and to make matters worse the idle speed has jumped up now is good and warm !
Just dont seem to get a break with this engine
#19
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Car: 1991 Trans Am GTA
Engine: 350 carbed
Transmission: T5
Axle/Gears: 7.5 10 bolt 4.10
Re: New engine will not run smooth
The idle is probly higher now because you were having to adjust some things before trying to get it to idle right but it never was with those damaged plugs so you will have to probly just re-adjust idle etc.
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Car: 1991 Trans Am GTA
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Re: New engine will not run smooth
Glad to see its getting better though. I wouldnt run it much without finding a shorter plug if it was me. Also nice to see you didnt go ripping the motor apart for no reason.
#21
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Re: New engine will not run smooth
No reason? Gaskets and plastiguage are cheap compared to hard parts. A motor that was built by "Wild Bill", is supposed to make 500hp through 600cfm and performer RPM heads, and has sat for 4 years? I would call those red flags. But what do I know compared to the vast wealth of internet experts. I only used to do these things for a living. Carry on.
Personally, I would rather know what I had, and know that it was right. Glad you got it running better. Wish you luck.
Personally, I would rather know what I had, and know that it was right. Glad you got it running better. Wish you luck.
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Re: New engine will not run smooth
No reason? Gaskets and plastiguage are cheap compared to hard parts. A motor that was built by "Wild Bill", is supposed to make 500hp through 600cfm and performer RPM heads, and has sat for 4 years? I would call those red flags. But what do I know compared to the vast wealth of internet experts. I only used to do these things for a living. Carry on.
Personally, I would rather know what I had, and know that it was right. Glad you got it running better. Wish you luck.
Personally, I would rather know what I had, and know that it was right. Glad you got it running better. Wish you luck.
I was told 450 on us gas and maybe 500 on uk higher octane gas.
I can only go by what I was told.
If I could find this Will Bill I could ask him but I've not been able to find him anywhere - just a lot of hearsay.....
I thought the carb was small for the power quoted but it came as a package so I went with it !
Hopefully it will run well and I can use it as me weekend toy until I finish the rest of the car.
If not then ill pull it and rebuild it.
I'm not going to pull it just to check it out. I don't have the time or space to do that at the moment and the car is in the way at the shop.
Don't think for a second I haven't taken on board the advice you have given but I just can't pull it at the moment.
I hope you'll continue to offer advice as I go on.
At work we deal with everything from old VW golfs right up to Audi R8's and we are good at it !
This carb and pushrods tech is just so far out of our comfort zone over here.
We just don't have anything like it !
Makes parts a nightmare even though I'm in the trade as well!
It's like being back at college learning again.
Just please bear with me
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Re: New engine will not run smooth
Ok spent a bit more time getting the timing right and she runs much much better.
Found out that if you retard it too much the headers glow !
Anyway got it sorted.
Next step shorter plugs and a rolling road visit.
Just wanted to let you know the outcome
Found out that if you retard it too much the headers glow !
Anyway got it sorted.
Next step shorter plugs and a rolling road visit.
Just wanted to let you know the outcome
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Car: v8 s10 and a stock 1989 firebird
Engine: s10 is 355 firebird is 305
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Re: New engine will not run smooth
well how did it do?
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