[AdamIsAdam]

Originally Posted by STEELCITYFIREBIRD

What is the casting #.

Now you have me nervous. what year is it?

[STEELCITYFIREBIRD]

http://www.wallaceracing.com/enginesearch4.htm

Scroll down.

[HWYSTR455]

78w72 - Sorry if I came across wrong, wasn't meaning anything insulting.

Yeah, I can take a swing at it Adam, but it's still speculation to some point, so please take with a grain of salt.

The surge, a few things can cause it, but yes, a vacuum can setting might cause that. My comment was regarding the fact of if it was ported or not, since at that point, the throttle blades are open, so it would be seeing the same amount of vacuum regardless. If your getting 18 degrees of advance from the can at idle, that's a lot, wasn't even sure those cans could provide that much. I thought they only did like 14-16 degrees, but not sure. You throw 36 degrees at it at idle, then something else is off, like I'm thinking carb. I would also check for vacuum leaks.

So when you crack the throttle, say like giving it 1/4 throttle or more, vacuum drops, so it's going to immediately pull 18 degrees of advance out. Hook a vacuum gauge up and hold it at 3k rpm, and watch the needle. If it's swinging around, then the advance is prob an issue/cause.

It would be better to get more advance at idle with initial, would be more stable, especially in transitions. But to do a lot of advance at idle you would need a mini starter. As an example, my driver was setup with 16 initial, 16 mechanical, and 10-12 vacuum. All mechanical was in by 2800. I tried more advance before, since everyone said e-heads like a lot of lead, but mine didn't, ran best that way. As another example, many new cars with EFI run 20-22 degrees initial. The iron head 442 I have likes 16 initial too.

Like I said, on the can, if you turn it all the way in and it bottoms, like stops turning, then the screw didn't fall out.

You can get a cheap hand pump at the auto parts store for like $25, good tool to have. Think I have an Actron one.

36 at idle is too much by the way, something is going on there. I would verify the timing mark on the balancer for starters, recheck your idle mix screws and idle speed, with the vacuum can disconnected.

The curve sounds close, but, if you run more initial, you will have to limit total more. Think you just need to spend a little more time dialing it in for your combo, like I said, you're close.

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[HWYSTR455]

Flip the block over and post a pic of the main webbing, that will be the give away, if they are undercut or not.

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[STEELCITYFIREBIRD]

Originally Posted by HWYSTR455

Flip the block over and post a pic of the main webbing, that will be the give away, if they are undercut or not.

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I think it's in the car.

[HWYSTR455]

Originally Posted by STEELCITYFIREBIRD

I think it's in the car.

That would make it difficult to flip over then.


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[HWYSTR455]

Did I read that right, this is a 469 with iron heads, 10.4 SCR, and an XE274? And there's no detonation with 32 degrees and 18 degrees vacuum advance?

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[AdamIsAdam]

Originally Posted by HWYSTR455

That would make it difficult to flip over then.

Whew! I was getting tired of holding the car upside down with one hand while holding my camera in the other!

I'll put a vacuum gauge on there and see what it's doing at 3,000 RPM. Good idea. Can I connect that gauge to a ported line since that's all I have left open? if not, I'll just pull another hose off the carb temporarily.

But yes, when it's got 36* of timing at idle (12* initial + 24* MVA) it feels great as I let the clutch out - SOOO responsive, and the temp immediately dropped to below 180 even idling/driving/idling for nearly 2 hours of testing.

Anything more than 12* initial and it gets hard to start. I have a high torque starter, but I suspect it's a cheap one (note how they spelled "protork"). found the link to the starter.

Wait, I have a picture of it here somewhere... FOUND IT! This picture I DID take with one hand while holding up the car with the other. I know, I know, I should really have set it down on jack stands

Originally Posted by HWYSTR455

Did I read that right, this is a 469 with iron heads, 10.4 SCR, and an XE274? And there's no detonation with 32 degrees and 18 degrees vacuum advance?

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Absolutely correct! That has stumped a few others too, including Richie. But his ears also agree, no detonation (well, until now on part throttle as I mess with the carb, but when I had the holley on there, no pinging anywhere on pump 93)


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[grivera]

Glad to see you're making progress and sorting things out. The engine type number should be by the distributor hole- at least it's that way on the 69 and 73 blocks I have...

[STEELCITYFIREBIRD]

Hope I am wrong on the block.

[78w72]

Originally Posted by HWYSTR455

78w72 - Sorry if I came across wrong, wasn't meaning anything insulting.

wasnt taken that way at all, & my comments weren't intended that way. just saying what i found on my cars & what i was instructed to do by the guys i paid to do the work on my carb & dist. i dont claim to know the facts behind it. each person will have different results i guess.

luckily i never had cooling issues to make me have to stick to MAV, also never had an adjustable vac adv to try & dial in. when my 78 t/a's engine was rebuilt & dialing it in, it surged & bucked a bit at the speed/rpm i mentioned, going to ported vac stopped it 100% & it seemed to cruise, idle & just run better. stopped the minor bucking 100%. i did remove all the emissions & TVS related vac lines & hook the vac adv directly to a ported source on the carb. my understanding of ported vac is to not have constant & full vac on the vac adv at idle, rather have it come in gradually off idle & at light throttle/load situations with higher vac, where its most beneficial.

i think ported vs manifold vac is like oil debates, the threads could go on & on & usually do. use what works best for you is all that matters.

[PontGuy]

Just use a plastic T on the tubing going to the distributor for the vacuum gauge hookup. Since you are using manifold vacuum that should give you exactly what you need to know. As for ported vs non-ported, I've tried it both ways on various engines over the years and always end up using manifold vacuum. Whatever works..

Pretty impressive that you don't have a pinging problem with that cam and C/R. Must have been built right. I wouldn't try to run too much vacuum advance though. I have a 14 deg can in the Lemans and 10 deg in the T/A. All engines are different but I know 20+ deg vacuum advance would be asking for trouble in my engines and they are milder than yours.

Suggest that you concentrate on setting the advance to optimize performance and drive-ability, and then take a look at cooling capacity if it still wants to run a bit hot. Trying to force it to run significantly cooler by adjusting advance is probably not a realistic goal.

Not sure if it is any easier, but another sure way of checking to confirm an early block is the bolt holes for the engine mounts. The early blocks don't have the additional holes needed for the various 70's style mounts.

[HWYSTR455]

Do you have build info, like how far in the hole the pistons are, chamber volume, piston relief volume, bore, stroke, rod length, etc? How was static CR calculated?

And what kind of balancer again? Have you verified the timing mark with TDC?

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[STEELCITYFIREBIRD]

This combo sure is sounding lets say, "more than less... than ideal."

[AdamIsAdam]

Originally Posted by STEELCITYFIREBIRD

This combo sure is sounding lets say, "more than less... than ideal."

I'm confused by that remark. Are you saying it's less than ideal or more than ideal?

My paperwork on the build is linked on post #16 here or just click here. If you scroll all the way down, you'll find some measurements by the machine shop for the heads and other stuff.

It runs very well. I've only been able to time 0-60 and not 1/4 yet, and I got off three 3.6 second times in a row on a good traction surface. I'm totally limited by traction. I have to use drag radials or it's like driving in the rain.

I dyno'd the car when I first got it, but it wasn't running so well AND the linkage wasn't giving me full throttle. Kinda important! Even at that, I managed 350 HP / 450 torque at the wheels. And like I said, that wasn't even at WOT. That was with my old Holley DP which also wasn't running right. After Richie tuned it and checked the timing (which he left alone) and after I fixed the throttle, it was noticeably faster.

Now I changed to a Cliff's Qjet, changed intake from Performer to his modified/ported P4BQJ and have a full 1/2" RobbMc delivery system awaiting installation.

The one thing I can say is that my MPG nearly doubled so far

[HWYSTR455]

Yeah, the links didn't work for me.

[grivera]

Originally Posted by AdamIsAdam

My paperwork on the build is linked on post #16 here or just click here. If you scroll all the way down, you'll find some measurements by the machine shop for the heads and other stuff.

Sounds like a nice build.

Re: the PDF file you linked- on Butler's invoice it indicates the crank is a 3.00"/4.25" stroker but page 16 from Warden Porting and Flow Testing Service indicates stroke is 3.75" for purposes of determining compression. Am I reading it wrong?

[AdamIsAdam]

Some of the Warren info was incorrectly input. Not sure why, but it was.

HWY, and anyone who wants, PM me your email address and I'll just email the pdf to you. Not sure why some can't see the drop box docs.

[STEELCITYFIREBIRD]

click/x out the pop up and it works for me, it's a PDF so you gotta have at least the PDF reader from Adobe.
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Adam,On the bad end.

Find your block casting # yet?
Probably 500557.
Long stroke, sticky tires, high compression.. . A lot to ask of it, if it's that block.

Don't have time to research pistons, build sheet, etc. right now.
That's alot of wind & cylinder pressure with that cam and rockers, if your correct with your compression figure. Hopefully the pistons have a big dish or the chambers were opened up.

Don't shoot the messenger please! We are still speculating.

[AdamIsAdam]

I won't shoot the messenger at all. I do appreciate knowledgeable feedback.

The details are in that document, like 17cc dish pistons.

I'm not home to look at the engine. Which number do you want to see? Date code I think is B166.