Inliners International Forums General Discussion Engines GM 153ci timing questions... total advance

can anyone tell me what the base timing and the total "all in" advance should be for the stock chevy 153 engine?.....

I have a GM 181 engine that I have tried to set up with an EST distributor, but I cant get the distributor to time correctly.... there are too many degrees between base and "all in".... so when it sets at idle and runs and starts good, it pings terrible... when I adjust it so it doesnt ping, it idles rough due to the initial timiong being set too low...

It has been suggested to change from an EST to a HEI system, which I was told would give the dependable electronic ignition, but with the mechanical advance, which eliminates the need for a special timing procedure to get it set right....

HEI distributors listed specifically for the 181 is super rare, so I want to find out if the advance cure is correct in a HEI unit for the 153 is the same before spending more money on another system....

but I dont want a distributor with vacuum advance, but a full mechanical advance...


and...does anyone want a good, very little used 4 cylinder Delco EST system with ALL new components???

I do not see why timing for a 153 or 181 would be different. The cranks and cams can interchange with a bit of fuel pump lobe interference. Rods are the same length. How different can they be? The stock HEI is good for more rpm than anyone but an all out racer would use, and few of them would actually get there.

Why not bend the weights or weld the advance slot. I do it all the time on V engines. Limit the internal advance to 12-18 degrees to you can have 26-20 initial for a total of 38 degrees (or whatever the engine wants). This takes a bit of experiment to get the slot length right but it should be easier on the side of a 4 than in the back of a 8. Of course if you have a dist machine this is way easier. I have also just locked the advance out if it is on a radically cammed engine. My drag week camaro is locked at 40 and with a good starter rarely has a hard start problem. I find things with big cams and lower compression LOVE lots of intial and/or locking out. Even locked out I have still employed a limited vac advance (10-12 deg) to help with mpg.

one would think so, and maybe it is, but the same family of engines, only the 6 cylinder versions have different "All In" specs on the timing, and im about tired of all the experimenting that ive been doing, so I was hoping someone would have the specs so I would know for sure if the distributors can be swapped without the need for sending it out to a distributor shop to be worked over...

What if the idle mixture is to lean? Perhaps this is what is demanding so much initial advance . . .

the specs on the engine I have (gm 181ci) state 8BTDC, and it runs great there... its the EST distributor that wont allow me to have 8BTDC without it being too much advance at 3000rpm... OR, when timing it to 24BTDC @3000rpm, when it returns to an idle, the timing is setting at 0TDC, which is not enough to allow the engine to idle smoothly....

as I cant find timing specs on the GM 153 engine. I have a damaged mechanical distributor from an old 153 that I have taken in to the speed shop to have it repaired and set up to the specs needed for my 181 engine... they use the same distributor but im not sure the advance curve is the same for both engines.. I will know which direction I go from here by friday afternoon...

ive got an

I am far from an expert on this, however somewhere I have the chart for the 153. Initial timing and advance vary somewhat by year and application, but I wrote down the factory spec for the 153 that's in my CJ2a, which the factory originally put in a '68 Chevy II, as follows:
0 deg BTDC at idle
total advance 43-1/2 to 47-1/2 at 2500 rpm with the vac, 20-1/2 to 22-1/2 at 2500 centrifugal only
Dwell at idle 31 to 34, variation of 3 between idle and 1750 rpm
Vac at engine should be 17-21 inches at 750 rpm with the air cleaner off and the vac plugged
The chart also has spec to check the mechanical advance, but that is dependent on the particular distributor you're using. I'll look around this weekend and see if I can't come up with the chart.
If anyone has a spare rear sump oil pan for this motor I'd be very interested. The one in my jeep has had a hard life.

Thanks, BD1!! I'm getting the last of the parts collected to build my bored and stroked 153 street engine! I'll need those specs as a starting point for tuning it when I'm done!!

Here's a link that may also be useful:
http://www.tpocr.com/chevII1.html

I found my original Sun Electric sheet for the '68 153, and if anyone knows how to post it here, PM me your email and I'll send pictures to you to post. I had to pay $10 for this on Ebay, just to get the info, (I'm not a collector of pieces of paper), and I'm happy to share it if someone knows how to accomplish that.

Thanks, BD1!! I don't know how to post photos here, but the link you posted above is helpful!!

I'm getting close to assembling my 153 project. I'm looking for a stud girdle for the valvetrain. If I can't find one, could I cut down one from a 250/292??

Yes you can. Same spacing

Thanks, Tom!!

I got to looking for a stud girdle for my little 153 project. I was going to buy a six cylinder kit and cut it down, but they're going for $180.00 and more. Got to wondering if a girdle from an SBC would work and took my new four banger head and laid it down beside one of my new heads for my 406 Small Block project! Lo and behold, they're the same spacing!! Only difference is the rocker arm ratio!! You can buy a good SBC stud girdle kit for a little over $120.00 including shipping!!

If I ever do another six cylinder Chevy, I'll by the V8 kit and bob one section off of each bar!! That extra $60.00 bucks will buy a set of push rod guides or something!!

Excellent, that's what hot-rodding has always been. If you can't find it, figure it out for yourself.

COOL!

If you are an Inliner member I did an article on how to make a stud girdle - applicable for any wedge inline. About a couple years back.

Thanks, TFF!! I'll pull that up and print it if that's okay with you!!

In the meantime, I sold a couple of old items that I really had no use for and turned a good paying gig with my band, so I had some extra cash at just the right time. I was able to buy a new timing cover, a cam thrust plate, and a good SFI balancer for the little project!

Yesterday, I ran down every possible specification and measurement for the engine and ordered pistons and rings. Since my brother and I do a lot of custom work and have several shared accounts, I was able to get custom made, forged pistons and rings from a buddy of ours at RaceTec for a good price and got the exact right slugs for the application and performance profile I'm trying to assemble!!

Between 12Bolt Tom, Impala, Beater, and CNC, I've been able to find all of the exact pieces to make my combo work.

The RaceTec folks have supplied my pistons for numerous race and high performance projects and being able to custom order and work with the actual designer was just too good to pass up!!

I hope to be sending the reciprocating assembly to my machinist for a final balance in about four weeks!! Maybe have it done and running by Christmas??

Sure - repost it if you like. [img]http://[img]https://i.postimg.cc/7YwYcB4y/girdle11.jpg[/img][/img]

I hope you will post exactly what you have done and what parts you used. This is exciting. It's been a while since we talked about cams. What did you end up with? Where did you find a timing cover?

Frenchtown I'm guessing you just ran it through a band saw to keep the cut line thin, Or did you take that into account when you made the holes. That is pretty much the way I did mine.

The timing cover came from Evilbay! Listed under Mercruiser!! Looks really nice!! Came with seal and gaskets!

Impala traded a damaged roller cam for some stuff I had. I sent it to Oregon Cam Grinders and they repaired the damaged lobe and reground it to a good low end hydraulic profile!!

I using a SFI balancer from a SBC that I found in research. It's not an ATI, but it came highly recommended. Made in Australia and spun up to 18,000 rpm in testing. Since I'm only planning on turning this li'l feller 5,000 or so, I figure it orta do the job. I WILL have to redo my pulley setup.

I talked to RaceTec yesterday because they had not taken out my deposit. My contact told me that they don't take out the payment until they start machining the slugs. He then informed me that they had pulled the slugs and were headed to the mill. Next he added that they would PROBABLY be done this week or early next!! I went with a 9.75:1 forged piston with a 1.6 cc dome and a metric ring set.

I picked up a set of Comp Cams stainless roller rockers almost by accident. I was researching rockers and looked at these in two or three places. I stumbled onto a set for the 4cyl and they were on sale for less than half price. POUNCE!!!

I'll run down part numbers and pick up on details in the next few days and post them here or on the thread I started on this project.... a couple or three years ago!! Probably both threads!!

I remember about the damaged cam now. Glad it was fixable. It sounds like you are ready to roll again.
I have decided that a lot of my problem with getting things done is my shop. It is full of crap and is set up wrong. Over the years I've moved in new tools to where they would fit instead of to where they should be. Getting the shop set up right is what I need to do. It's working against me instead of for me.