getting the motor ready for aluminium

[170-3tree]

Okay everyone, I have the car running and nearly drivable, but am having huge problems tuning,

First, I am pretty sire I need longer pushrods. I have no idea where to get them, but am going to try a few places out.

Second is vacuum, I have it set up with both the PCV and vacuum advance on the manifold port using a vacuum T. I'm sure this is wrong because I get no vacuum for the dizzy. When I pull the vacuum off the manifold entirely, the engine races up crazily.

Any help with either of these issues would be greatly appreciated.

Thanks all!!

 

[FalconSedanDelivery]

Not sure what you mean about vacuum , but time it without any hose hooked to the dist , and never T a PCV hose , if possible more info please

 

[170-3tree]

I was afraid the T was the biggest problem.
Current setup: Manifold vacuum used with a hose running to a T one out to the distributor and one to the PCV valve. If I plug the PCV and check vacuum on the loose distributor vacuum line I get about ten to twelve inches, without plugging it, the needle twitches to some extent but never leaves the 0 range.
I am not trying to time it with the vacuum hooked to the distributor.
In case it helps anyone, I only get around 2" vacuum off the port on the carb, under any circumstances that should produce vacuum.

Okay some other things noticed since the last post, If i take out the T entirely the engine races to around 2200. Putting the T in with NO hoses off the T it cools down to around 1600rpm. hooking all the hoses up takes it back down to around 1k which is about where it runs decently and keeps running.

Unless I'm wrong, I should run the PCV off the port on the carb and the timing off the Manifold? I always had best luck using manifold for timing.

Thank you!

 

[bubba22349]

Yes you should hook the PCV off the vac. port on the base of carb if you have one and the distrib's vacuum advance should be hooked to a ported vacuum on the carb base. You can get longer push rods from C.I. ClassicInlines.com

 

[170-3tree]

I have used the classic inlines site extensively, and have not found longer pushrods without them being inches longer.

I prefer a manifold vacuum source for my dizzy so I think I might use the port for the pcv system and manifold port for the dizzy advance.

 

[FalconSedanDelivery]

There is always a discussion on Manifold vs Ported for vacuum advance , Ive done over a Thousand Distributor Re curves since I started my service back in the 80's , NOT ONE has used Manifold Vacuum , the ONLY time manifold vacuum works better is when the distributor has the WRONG curve in it and manifold Vacuum is band-aiding it , you do what you want , Just putting that out there . You must have something wrong if you need LONGER Pushrods , on a Shaft Rocker System , SHORTER is the rule when change is done , Milling , Decking etc , If you have a aftermarket system AND the stands are Taller , THAT would be the only reason for needing Longer Pushrods , again just saying

 

[170-3tree]

Well unless there is a mysterious vacuum leak that is affecting the carb port, but not the manifold vacuum, the carb is only pulling 2"hg, Seems awfully low to me to be a decent source of vacuum for dist advance. I went over everything with carb cleaner to check for vacuum leaks and didn't find one ANYWHERE on the engine/head. Maybe this carb is messed up somehow. There is only one vacuum port on it though.

As for the distributor curve, I have no doubt that it isn't 100% perfect, It is whatever came with the DUI standard, I believe 24*@3300 or something of that sort. I also do not have the knowledge, funds, or tools to recurve it. I just know that when I put it in initially it ran better (felt stronger, got better mileage) with manifold vacuum, so I will test both with the new head and see if I get similar results.

As for the pushrods, I don't know for sure, but I think that my old head might be smaller. I plan on pulling out the pushrods and seeing how long they are, so if You or ANYONE could give me a spec on stock pushrod length, that would be very helpful. I did notice though that my stock head is about 1/2" shorter than the AL head from classic inlines on the sparkplug side, and that seems to follow, suit in the case of the pedastal mounts for the rockers. all I know for sure is that it cannot be safe to have the adjusters ALL the way tightened and I do not see any way Putting a shorter pushrod will help that situation.
Thank you, all.

 

[FalconSedanDelivery]

OK some where I missed the I have the Aluminum head on , as the Thread is getting ready for it , so my bad with that said , so sure you may need longer push rods ,and that should of been checked on mock up , There are many company's make them , as for the carb pulling 2 inches at Idle that's about right for a ported source , as it will rise as you open the throttle , but will drop back to almost zero if you stab it wide open , please pardon my bluntness , but I think your a bit over your head on this project , you need someone , or learn more , if you Don't You will DEFINITELY Spend more , Dist re curves cost 89.95 plus parts , if that is out of your budget than you just proved the over your head quote , again sorry , but sometimes it's better to pay someone who has the knowledge than to pay twice because you don't.

 

[170-3tree]

It was checked on mock-up. I knew I would need longer ones at the time, but wasn't in a rush as, I still had adjustability and my primary focus was getting the car out of the college parking lot before I got a $500 ticket and impound bills to deal with. I knew I would need them soon, now I am in search of them. Mike does not have anything on his website about needing longer ones on being a possibility, and he doesn't have any longer ones listed for sale, like I had thought. So now I need a source for such a part.

I misunderstood the vacuum equation with the distributor. Or more like, got it confused from my literature. Thank you for setting that straight.
Over my head? no. I refuse too accept that. Or maybe I am, but I am doing a great deal to get my head over it. I have had a few hickups? yes, I came to the forum for assistance on those before they became issues, that turn into problems.

I suppose A little personal background would be helpful to get you and I on the same page, you are a Veteran at doing this, I am trying to teach myself with the help of the College, and books by Vizard and Smokey as well as this and other forums. This is only my fourth engine build, and the first that I did not go strictly stock on. I am a younger person, without fifty years of wisdom behind me, but in order to build such wisdom I need to dive in and try things, I need to be able to ask questions and get an explanation rather than just a shut-down "your wrong" reply. I knew that this was going to be a rough project, And I am being patient and absorbing everything that I do and learn so that it can be used in the future.

I also saw no point in making a new thread for after installation because this was easier for me to refrence rather than a thread for every step of the process.
Right now, $90 is on the "it'll have to wait" list, not out of the budget by any means, but if I can bandaid it for a couple weeks, I will, if not, I won't drive the car until it is done. I have no problem having someone do my Recurve, it is expected, because I don't have the tools to do it and I wouldn't attempt it until I knew what I was doing with every thing I changed.

Okay My apologies for the long winded response, but I feel that understanding each other is somewhat important, especially since you, FSD, been one of the biggest helps to me so far. I thank you for the bits of advice, I would still be stumped without it.

Okay now that my whole yaddy yaddy ya is over, where could I find a source for pushrods? haha

 

[wsa111]

There is always a discussion on Manifold vs Ported for vacuum advance , Ive done over a Thousand Distributor Re curves since I started my service back in the 80's , NOT ONE has used Manifold Vacuum , the ONLY time manifold vacuum works better is when the distributor has the WRONG curve in it and manifold Vacuum is band-aiding it , you do what you want , Just putting that out there . You must have something wrong if you need LONGER Pushrods , on a Shaft Rocker System , SHORTER is the rule when change is done , Milling , Decking etc , If you have a aftermarket system AND the stands are Taller , THAT would be the only reason for needing Longer Pushrods , again just saying

Dissagree, even if the initial & the centrifigul is dialed in i use the vacuum advance to give the highest idle speed & idle vacuum.
I also custom tailor the total vacuum total to match the combination, also use different cans & use different vacuum settings according to what is needed.
Yes on some engines ported vacuum is necessary, again whatever gives the best idle speed & highest vacuum at idle.
I have owned a sun distributor machine since i was in high school & have done many distributors, all depends on the application. Bill

 

[170-3tree]

Okay so when tuning timing for vacuum, do you use the manifold vacuum regardless of what you plan to use for your dizzy? I always have and had good luck. But just because it was the most available source for a gauge?

 

[FalconSedanDelivery]

Perhaps another can help there , I don't use that method as its a waste of time , Driving so as to keep the vacuum as high as possible and still stay in the highest gear is a benefit, and will help MPG ,

 

[FalconSedanDelivery]

Also Glad you still plan on doing it yourself , it was just a friendly warning , not to discourage , I do this for a living , its Not a Hobby , as is My Distributor Recurve Service , I see projects tackled with less than thought out plans , So that's all the above was about .

 

[170-3tree]

Oh, I have time to waste, I need to track down pushrods, install the new balancer, and order a few carb jets, before I can put her on the road. Until I have a balancer that has a proper timing Mark, I have just been fiddling with different things to see how good I can get it to run without. Plus that gives me a feel for all the new parts and such, what sounds good verse what sounds bad or wrong. Just for memory reference and to kill boredom.

 

[FalconSedanDelivery]

Well Not having the Timing marks is the ONLY time Ive ever used that method and then its just temporary , but whatever works for you in the interim , as long as your moving forward

 

[170-3tree]

I don't plan on putting a single mile on it until I can get a light on it and have a good mark, plus the balancer is real bad, I st the mark on it again, and it slipped again. So I don't even want to rev it up much because I fear it separating entirely now.

 

[wsa111]

If its a street driven vehicle & especially an auto trans deal, i use the VC-228 can a lot especially if the cranking compresion is over 185#. I adjust the vacuum side to full advance @ 10 & the no vacuum to 4.
If you have 18 degrees initial + 20 centrifigul = 38 you don't need much vacuum advance otherwise you will ping during light cruise during tipin of the throttle.

If its a race car use a crankshaft trigger cause you will never go full throttle under 2500 rpm.
In borderline applications i don't even use vacuum advance.

In a low compression street vehicle a little more vacuum advance can be used.

If you have a stock camshaft & using manifold vacuum & the engine flutters you are better off with ported vacuum & or limit total vacuum advance.

Faron is right there are so many variables that a trained professional can save you time & money by doing it right the first time. Bill

 

[170-3tree]

Well as FSD stated, doing it wrong costs more, so I am waiting for new lifters right now. OOPPSS.

Luckily my cam and the wear on them after running for about an hour looks perfect, but having the rockers well over adjusted messed something up in the bleedown structure of most of the lifters. but did not do any damage other than that. they were probably messed up the second I put the rockers back on, as I got ahead of myself and didn't loosen up the adjusters to put the rockers on. I did use one of the good ones to check the geometry, and it seems that milling the block actually made the geometry perfect, as before they were borderline OK or too short.

As for advance, I will spend many hours of free dyno time getting the engine tuned at the college to figure out exactly what is perfect for the car between jetting and vacuum advance methods. I will also invest in an AF gauge to get a nice fine tune going.

I have a question though, as the ported vacuum source only supplys about 2"hg at idle, does this mean that my initial advance could be higher? or the same as manifold supplying 14-16"hg at idle?

I am taking a class this semester in which the teacher has already went through the loops to get me as much dyno time as possible, saving me hundreds of dollars. In conversation with the teacher, he is excited to see what can be squeezed out of the engine, and how much each little tweak will affect my numbers. His goal for my end hp is significantly more generous than mine, as he thinks that 170-185whp is going to be no problem with the setup, I am just hoping for 150whp. maybe to keep from getting my hopes up I suppose.

Later in the semester I might swap cams to something a bit more agressive and also move to an electric fan, but that will take an alt swap and most likely a pretty thorough rewire of some or all of the car with larger wires. I will eventually upgrade the carb to the 500cfm holley and do the annular mods to it, but that will be after quite a few other things happen to the car.

 

[FalconSedanDelivery]

Do yourself a favor and disconnect the vacuum advance until you have the rest tuned , it will get rid of a variable that wont effect power ( if its set right ) , but could case problems ( if its not ) and to answer your 2 inches , yes it might , no way to know unless you check it yourself or on a machine , make sure you have the lifters adjusted correctly and use lots of break-in lube and a zinc additive , Just like breaking in a new cam and lifters ,

 

[170-3tree]

I know to tune it without the vacuum advance connected. From what I understand I should be able to drive it to some extent with no vacuum advance. But I will get it operational with to better driving until I get it on the dyno and see what is best.