The Dodge Challenger Message Board

I have strange problem with my ignition system. It is all new MSD ignition with billet distributor and 6A - MSD ignition control. The problem is The ignition is set apprx 17 deg before , at the idle when i puch the accelarator pedal it first goes after and only later starts to go more before. Because of that engine is very sleepy when you kick the pedal only after a moment starts to go.

The other problem is with the idle speed.When we set the idle at the park position to 800 rpm, after changing to drive engine stops, i have to have idle min 1200 rpm to be able to put drive. The camshat is from Hughes engines and is relatively mild



Camshaft Technical Details
Intake Valve Lift 1.5
Exhaust Valve Lift 1.5 .506°
.524°

Intake Valve Lift 1.6
Exhaust Valve Lift 1.6 .539°
.558°

Intake Duration at .050"
Exhaust Duration at .050" 223°
228°

Lobe Separation Angle 111

Intake Opening at .050"
Exhaust Opening at .050" 3.5° BTC
48° BBC

Intake Closing at .050"
Exhaust Closing at .050" 39.5° ABC
0° ATC

Min. Suggested Cylinder PSI 160

Sweet Spot RPM 1800 - 5400

i am also running 360 heads with big valves 2,02 and 1,6 + porting, + adjustable rocker arms

Edelbrock performer RPM intake

Speed demon 750 Cfm carb Vacum secondaries

Keith Balck dome pistons

compression ratio is 10,5 :1

all based on 318 block

The engine is not bad at higher RPM but it is absolutely weak at low

Sorry if i have made some mess in my explanation but i am not so good in mechanics.

I need to know the answer to this question.

Does the distributor have vacuum timing advance at all?

While waiting for the answer I can inform you about some other things.

Idle torque needs to match the torque converter stall speed.
If not then the idle speed will drop when you put the car in gear. This seems to be what is happening.

Two reasons why this could happen;

1) The longer the duration of the camshaft, the less torque you have at low rpm, and so the higher stall speed converter you need.
If you don't have enough stall speed for the engine the rpm could drop so much in gear that the engine will die.

2) If there is something wrong with the engine or if the carb is not tuned correctly then you could simply not be making enough torque in the engine to keep it doing in gear. Vacuum leaks can do this too.

Have you got a vacuum gauge? If not find one. Put the vacuum gauge onto the port that would normally feed the distributor. This port should be fed from a hole above the throttle blades in the carb so that at idle it does not "see" manifold vacuum.

If there IS vacuum measured on this port the carb is not set correctly and it is not running on the idle circuits.

The throttle blades need to be closed enough to loose any vacuum on this port.
If the idle rpm goes below 800rpm when you do this you need to supply more air to the engine. On modern demon carbs they have an air bleed in the middle that allows air in. If you adjust this the engine rpm should increase so you can close the throttles enough.

Only when there is no vacuum on the distributor port will the idle circuits work. You can then adjust the idle screws to be just rich enough to get a max rpm and then turn them lean again until you just get a slight rpm drop. Or you can use the vacuum gauge in the same way to get just under max vacuum.

This will also ensure that the vacuum secondaries and any vacuum advance on the distributor work correctly.

If you do not have a vacuum advance it could be that the high idle speed you are using is brining timing in and then when you push the throttle and the engine rpm drops the timing might be backing off.

So my suggestion is that you tune the carb idle correctly and make sure that the stall rpm of the torque converter matches the duration of the cam.

Thank you Dave for prompt answer. Today i made a small test i managed to dcrease the idle speed from 1300 to around 1100 rpm at the park position, and it seems that car started to go better from low rpm, mayeb it is only self suggestion but it seems so. As the the torque converter i am usin stock one that was originally mounted to my 318 with 904 transmission.

I have follwoing distributor :

http://www.msdignition.com/pdf/8534_frm23870.pdf

As far as i know it does not use vacum.

For the vacum leak i think that i might have it. When i push the pedal of the brake i hear sth like : psst, also my power brakes do not work so good on low rpm i must use more force to brake, at higher rpm it looks i need less force to push the brake.

You need to do as I said and get the idle rpm down to 800rpm. Now way should the engine be idling over 850rpm with that cam. If it can't be done with the Demons "easy idle" (or whatever thay call it) adjustment then drill a couple of holes in the primary throttle blades as descrbed in my carb tuning stuff on here.

To be honest. I have heard of idle problems with Demon carbs. I have also had difficulties with an older Demon. Considering they are supposed to be the mutts nuts I am so far not very impressed with them. They look nice but I am yet to see much of an advantage for your money over a standard Holley. Which is a shame.

If you do have a vacuum leak it will cause big problems.

If you get the thing idling as it should and still need a higher stall converter get one. No such thing as being "stuck with the standard one". Find one for a six cylinder at the very least. That will stall higher on your bigger engine.

Yesterday i have tuned the carb accordingly to your instrcution. Once again it seems that when you want sth done corrctly you have to do iyt yourself. The guy that was putting the engine together was adjusting idle with screw resposible for primaryt butterfly position. It was causing situation that all the time was like throtle was open litle bit. That was causing big drop of RPMs when changing gear to drive. It was also the reason of timimng backing after pushing the throtle. I have adjusted thi yesterday and it seems to be much better. Today i will receive vacum gauge so i am gonna check it correctly.

Another thing i have a nasty leak of oil somwhere between transmission and engine any ideas how to correct it ?

Thank you once again for you support

Engine oil or transmission oil? Coming out the bottom of the trans bellhousing?

Engine oil = rear main seal. Big job. Need to remove the crank to replace it. It should be replaced with a good quality seal every time the crank is removed.

Trans oil = trans input shaft oil seal. Easy to fix but you need to drop the trans and remove the torque converter to do it. This seal should be replaced every time the trans and engine are separated.

Make sure you find exactly where the leak is coming from. If it is other than the bellhousing it could be a number of things.

the engine goes out on Sat, i have blue smoke and oil is disappearing to quickly as for the leak. probably another failure of former mechanic or machine shop. will see. If this is sth serious i go for 426 stroker from Hughes and rebuild it once again, no driving this year (just my credit in the bank will be bigger). if not i fix and drive it for one year and then put stroker in it. Do you know if you have to use r3 block for these strokers or you just can live with regular 360 block. talked to hughes but forgot to ask about it. they say it is possible to have 600+ HP from this .... very intresting. light and powerfull small block can be really nice.

I think Hughes only use standard blocks in their strokers.

I would personally keep the power to under 500hp though to keep it drivable.

To be honest the more I look into strokers the more I don't like them. I much prefer an engine with a bore larger than the stroke and as long a con rod as possible.

Engine is finished, after 1000 km almost all inside is broken.
Bore not good, rings destroyed, valves damaged, rocker arms shaft wera visible. Disaster.

All the parts were new, i have changed the oil twice during this 1000 km together with oil filter, i was not going over 3500 rpm and using the car carefully. Real mess. Only what is strange all the bushings are OK.

What i have found out after disassmebling was that first and the second ring were switched, guy making assembly of the engine did it wrong, but why i see all this other things destroyed ?? Heads had new bronze valve guides and i see a lot of wear on valves stem. Valves were stainless steel with chrome stem bought from hughes engines, also the valve heads on the inside part show a lot of wear. All the people that have seen says that it looks like the engine did 200000 or 300000 km. I was also using camshaft from Hughes and hard springs that they suggested, is it a reason of valve wear ??

Please somebody try to expalin what can happened as i am now without an engine after i have builded completely new one with all new parts> i have already lost a lot of money because of that and can not afford having similar situation once again. Of course mechanic that did the engine say it is not his fault and will not pay for rebuilding the engine.

Did the valve guides have the correct clearence for the valvestems? They run tighter than stock because they are "self lubricating". It looks to me that the valves were loose in the guides and a lot of oil was getting sucked in there.

Or maybe they were too tight and galled which would tear bits of the guides and stems?

Are the valve stem oil seals OK?

Is the wear on the valve stems or guides measureable or do they just look bad? i.e. can you rock the valve from side to side when lifted just off the seat?

The wear on the cam lobes looks odd. Were the lifters free to rotate before the engine was started for the first time and the cam broken in?

You just lightly oil the lifters and spin them with your fingers before you fit the pushrods to make sure they are nice and free.

I can't imagine it has anything to do with the supplier. Hughes don't actually make the cams themselves. Or the valves. Most times things like this happen it is due to poor workmanship and lack of understanding with these types of engines.

Small block engine? Looks like an oiling problem. Check to see if the oil passages are clear. Also check the head gasket that it matches with the passage between block and head. We used to drill the rocker oil supply larger to increase the flow up to the heads. Oh, check that the rocker shaft is installed correctly allowing flow to the rockers and thus the valve stems.

Check the oil pump and pickup. Do you recall low oil pressure when operating the engine?

That is a real bummer man. Hope this helps in the future at least.

Oil pressure was good i had around 60 psi at the idle, as to the oil passages i will check it Monday. Valves had some loose in valve guides but it was not big, i am more concerned why the head of the valve was so damaged ??
I think i will reuse only some componenets of this engine, buy 360 block + stroker to 408, heads i will leave alone i will oredr Edlbrock heads assembled with valves, i am just worried about the valve springs wheather to use the ones that wil be with the heads or use the ones Hughes supplied for the camshaft. Valve heads wear shows that maybe springs were to hard? If you guys have any suggestion please feel free as i am once again at the planning stage of work. I wil graetly appreciate your help.

No way you should use any valve spring other than the one that matches the cam.

What model number spring is it? I would put money on my springs being even stiffer.

The damage to the seats look as if it is only on one side?

Are you sure the was no contact with the pistons?

The springs are :

1110 120# @ 1.660" Installed 310# @ .550" Lift

Installed Height/Pressure: 1.660"--120#
Pressure @ .450" lift: 280#
Pressure @ .500" lift: 300#
Pressure @ .550" lift: 310#
Coil Bind: .620" lift
Outer Spring ID/OD: 1.033"/1.440"
Type of Spring:Single w/ damper

Yup. Mine are stiffer.
No problems with mine.

Is the seat damage just on one side of each valve and is it every valve?

It looks odd to me. Like it has been rubbing against the piston top.

Any witness marks on the pistons?

looks damaged on every valve. No marks on teh pistons. Very strange. People from the machine shop say that the valves look like they were made from very soft material and the chrome on the stem is more decorative than technical it is easly rmoving with scraping tool.
What do yo think about Edelbrocks ? and stroker ?

Chrome on the stem??

You not got one piece stainless valves?? Always use the one piece stainless.

Yep, also from Hughes

1006 One Piece, Chrome Stem, 21-4n Stainless Steel.

Head size: 2.02"
Length: 5.011"
Stem diameter: 11/32"
Type: A

Well I don't understand and without seeing the engine myself I can't say but it sure looks to me as if it has been put together badly. The valves must be either too loose or too tight in the guides. Plus how come the intakes have all they crud on the backs of them? You normally only see that after thousands of miles. It must have been burning oil badly.

The springs couldn't damage the valve. That is silly. And how come they look as if they have been hitting something on one side?

You said "Valves had some loose in valve guides but it was not big, i am more concerned why the head of the valve was so damaged" but if the valve is loose it may not land square on the seat. Especially if the valvetrain geometry was out.

If the rocker shafts were installed the wrong way around you would cut off a lot of the oiling to the rockers, outside of the shafts, pushrod tips, and the valve stems. If the surface is coming off the stems they must have been red hot.

The cylinders and cam look as if the engine was not broken in correctly. Plus it looks as if the pistons were too tight in the cylinders.

The bottom line here is this. Next time measure ALL the clearences yourself. Get any machining done by someone but check it later and assemble EVERYTHING yourself. That way you know it is good and you know who to blame if something goes wrong!

My friend is doing this right now with his 440. He trusts no-one and I don't blame him.

As for the quality of the parts you have. There are a few things about Dave Hughes business that I don't like. But I trust his parts completely. He uses only the best for the job, advises which parts you need for the job, and tests all his parts many times over. He does a lot of business and I have never come across this before.
Those same valves are also sold by many other engine builders. They are not made by or for Hughes Engines. They are a commonly available valve used by many people.

However if you feel it could be that you have a faulty batch you need to contact Dave Hughes and see what he says. He might have a better idea of what might have gone wrong.