Timing Questions

[Deathproofcuda]

If you set timing to 15 degrees BTDC with vacuum advance disconnected, then connected the vacuum advanced to a ported vacuum connection on your carb and your timing advanced to 35+ degrees then the throttle blades on your carb are open too far. You need to adjust the throttle blades closed so that there is no vacuum signal from the ported vacuum connection on your carb.

 

[Xcudame]

Sounds like a little too much RPM and a bit too much timing to me. Back off both and it should be good to go!

 

[moparleo]

Try to back away and take a wide shot of the engine compartment..
Since the FSM shows that a 1971 440, 9.7:1 compression tests at 110 PSI, the 1978 speced @ 7.5:1 and that is in a perfect world and your test was 125-140 PSI. Big difference. Was the engine in the car when you bought it ?
Who knows what is really inside the engine without pulling the heads, which wee also different on the motorhome engines, so also different spark plugs. They used a plug specified for Winnebago Motorhomes,
I f the Camshaft is not stock etc... these numbers are moot.
Better info, better answers.
Vacuum leaks, different advance curves in the distributor all have an affect on detonation.
There are stock specs, and then there is everything else. The closer to stock that your combo is, the less problems you will have and the easier it will be to increase actual performance.
A stock, 78 motorhome engine in an E-body is not the ideal combo for handling, mileage, performance. A lot of nose weight. Front brake load etc...
Looks more impressive but a mild Small block has much more overall performance potential.

 

[Kuruton]

Did you verify the timing marks on the harmonic balancer to see if timing marks are correct? We always try to verify those before we do any timing work. If that is off by even a little bit it changes the timing quite a bit.

I have not, I am going to work to replace the timing chain and do that as well here soon!

 

[Kuruton]

By the way, the link for the distributor took me to a Mopar small block. That must have been a mistake as a small block distributor wouldn't bolt up. Hopefully you got this one:
DODGE Summit Racing SUM-851005-1 Summit Racing™ Billet Electronic Mopar Distributors | Summit Racing

Timing should be set with the vacuum advance port capped off. Shoot for 32-34 degrees total. If your at 15 degrees by rotating the distributor plus the 22-24 mechanical advance of the distributor, you're between 37-39 degrees and that's too much and it's going to ping! Try 10-12 degrees before on the timing mark.

Sounds like a little too much RPM and a bit too much timing to me. Back off both and it should be good to go!

Yes my bad, that is the correct one. I am going to try that, but I noticed its a little slow to start when I had it set at 10-12, I might have to try slightly stiffer springs or adjusting the max mechanical?

I also realized that I'm just a huge idiot after not being able to replicate the weird vacuum coming off that timed port. I think when I initially did it, I was probably at high idle from my electric choke. I'm learning as I go!

 

[mrmopar340]

I have not, I am going to work to replace the timing chain and do that as well here soon!

I use Cloyes billet timing sets. Double roller. I was using another brand beginning with E but they stretch far too easily for my stuff. Def check TDC and see if it aligns. A few degrees can make a big difference.

 

[Kuruton]

Try to back away and take a wide shot of the engine compartment..
Since the FSM shows that a 1971 440, 9.7:1 compression tests at 110 PSI, the 1978 speced @ 7.5:1 and that is in a perfect world and your test was 125-140 PSI. Big difference. Was the engine in the car when you bought it ?
Who knows what is really inside the engine without pulling the heads, which wee also different on the motorhome engines, so also different spark plugs. They used a plug specified for Winnebago Motorhomes,
I f the Camshaft is not stock etc... these numbers are moot.
Better info, better answers.
Vacuum leaks, different advance curves in the distributor all have an affect on detonation.
There are stock specs, and then there is everything else. The closer to stock that your combo is, the less problems you will have and the easier it will be to increase actual performance.
A stock, 78 motorhome engine in an E-body is not the ideal combo for handling, mileage, performance. A lot of nose weight. Front brake load etc...
Looks more impressive but a mild Small block has much more overall performance potential.

I appreciate the info. Unfortunately I didn't have much info on the car when I bought it since it came overseas. I googled the VIN and found a listing when it was sold in Florida a few years ago but it never listed any engine specs, so I just assumed its stock. It very well could have some mods that I'm unaware of. When I did the valve covers and valley pan, I didnt notice anything extraordinary. The lifters and stuff are definitely stock. I'd like to get deeper into it and figure out what Im working with but it's hard to find people here who can work on these engines, so I'm kinda just figuring everything out as I go.

Up until I bought this car 8 months ago, I had never so much as changed the oil on a car. I had worked on motorcycles a bit but even that was just all self taught/google/youtube.

I've managed to install the QA1 K-member, Lower and Upper arms, new shocks, strut rods, sway bar etc so the suspension isnt nearly as bad anymore. Could use some work on the rear still for sure though and new torsion bars.

 

[Kuruton]

I use Cloyes billet timing sets. Double roller. I was using another brand beginning with E but they stretch far too easily for my stuff. Def check TDC and see if it aligns. A few degrees can make a big difference.

Will do! Been researching and will make that my next project. That was part of the reason I had timing set at 15ish because I assumed the chain was stretched.

Its a double edged sword coming to the forum haha. I get a lot of good info, but my list of work keeps growing!

 

[mrmopar340]

Will do! Been researching and will make that my next project. That was part of the reason I had timing set at 15ish because I assumed the chain was stretched.

Its a double edged sword coming to the forum haha. I get a lot of good info, but my list of work keeps growing!

It seems to never end but that first drive will make you forget the rest.

 

[Kuruton]

If there is a lot of carbon & junk built up on the pistons & combustion chamber that can certainly raise the compression. That could also account for the pinging.

I had stuck a camera in cyl 1 a month or 2 back and it looked surprisingly clean. some definite scoring on the walls but, from my limited knowledge it looked decent. I have only checked that cylinder though just because I was interested to test out the camera. I might have those pictures still though and can upload them tonight to see what you guys think

 

[Xcudame]

Cloyes true rollers are some of the best timing sets in my opinion! I still think a little less RPM and initial timing will do the trick! If you get a vacuum gauge, my dad always said advance it until it talks to you (maximum vacuum reading) then back it off a little (1 or 2 inches of vacuum)!

 

[moparleo]

Before you dig yourself a deeper hole, I wouldn't be messing with advance curve changes and such. You really don't even know what is inside the engine.
Factory ignition is cheap, trouble free. A stock 1978 440 is a 7.5 : 1 compression engine. It doesn't want any excess timing. This is not a 1970-71 car engine. Low comporession, didfferent heads, smog cam. The timing specs for this is from a 1978 Motorhome if stock. All the ealy tuneuop stuff will be wrong.This is just dart board tuning. Even a person with much tuning experience with these engines wouldn't just start to make changhes without knowing where he is starting.
I hope you are not baseing the changes you are making on the engine from just Youtube videos..
You say that you are going to change the timing chain ? Why ?
Really that is like baking a cake and you just have some ingredients ,maybe even some wrong ones and no recipe.
Not likely to taste good.
I posted a page from the Factory Service Manual for a 1971 Dodge/Plymouth car. Timing is 2 1/2 ° =/- 2 1/2 ° BTDC.
That is for 9.7 TO 10.5 :1 compression motor, not 7.5 : 1.
Find out what exactly you have before it becomes a $$ hole.

 

[moparleo]

Reading back on an earleir post, You are basing the build and mods from just Googling a block casting number ???? WOW.
You say that prior to this car, you never even did an oil change on one.
You need lots of non metric tools. Service manuals, clean place to work/store the parts you are taking off. Lots of documentaion as you go.
don't even know what to say as I really think this over. It is usually much better to learn how to walk before you start to run races.

 

[Kuruton]

N

Reading back on an earleir post, You are basing the build and mods from just Googling a block casting number ???? WOW.
You say that prior to this car, you never even did an oil change on one.
You need lots of non metric tools. Service manuals, clean place to work/store the parts you are taking off. Lots of documentaion as you go.
don't even know what to say as I really think this over. It is usually much better to learn how to walk before you start to run races.

Not sure why you're so hyper critical over some simple questions. I have a full kit of tools, access to all service manuals online and a full shop with a lift that I rent for 5 bucks an hour lift time. I managed to install AC, redo the entire front suspension, reweld/patch the frame, install new rad with electric fans, water pump, carb rebuild, alt, full interior, drum to disc conversion, etc.

This is just another hobby I'm spending some time in because I enjoy the type of car. I have no intention of making this my life and am just enjoying learning new things. I've built motorcycles from scratch, I've just never delved into cars until I had the chance to get a garage to work out of.

You're harping on really odd things and not being particularly helpful. Can provide input or don't, no use in being hostile.

I've walked plenty and am getting into running but have questions along the way. You're from Moreno Valley where there's someone with knowledge on classic cars within spitting distance wherever you go. I live in a country where it's rare to see a car more than 10 years old, and I've seen maybe 5 American cars from pre-90s in 11 years.

I based the build off the intake casting, block casting, what I saw when I did the valley pan, and valve covers, prior listing of the car, as well as just the amount of power it puts out.

I'm doing fine

 

[moparleo]

Sorry.