1972 Maverick Sprint - Phase 2

[ttamrettus]

sure is pretty

[Maverick]

WXO arrived at 8AM this morning. We had to start early because we both had other things going on in the PM. Things were somewhat organized and the trans and engine were mated but the bell housing bolts just needed to be torqued. Got that done and up in the air they went.





And down into place with many hitches.






We had to stop earlier than planned because the exhaust ports in the heads, openings in the header flanges, and the openings in the gasket were all quite different dimensions. Think there'll be a compormise in the gasket dimensions and some port matching/tweaking to make things match a little better. Never knew there were so many different SBF exhaust manifold/header haskets. A set that are SUPPOSED to match the heads are on order from Dart. These guys have a selection. http://catalog.remflex.com/category_s/98.htm If the Dart gaskets aren't what's needed, one of those sets will probably be close.

Tomorrow we haul the 5.0 and meet the buyer in Spartanburg, SC to complete that transaction. Its wrapped in three layers of plastic (might rain) and loaded on the trailer with the engine lift. We'll meet him and transfer the engine to a pickup truck at a truck stop off I-85.

[oldvettedad]

Totally impressed with the progress you are making. I too am impressed with the dyno numbers. I don't know if hs 425 was accurate, but losing 15 hp dropping down to a 600 cfm carb seems about right. If thats a true 410 HP your strip times will really pick up. You know your limitations, rear gear ratio, tire, converter and tranny, maybe your headers (especially if your port matching problem on the exhaust is big ports to small headers). Of course thi is not a race car so you don't want to compromise driveability. But just as an example, my Chevy II 327 only has about 425 hp. But with a racing tranny, low gears, spool, 2 inch step headers and a big tire it runs consistent mid 11's. With abetter converter, a little less agressive rear gear and slightly smaller tire it would probably be consistent 11.40's. The point is, you have plenty of power, and if it is comfortable to drive, you have a perfect street strip car. I can't wait to see it running!
BTW, the second install went a lot faster than the first

[oldvettedad]

BTW, I noticed he was using an electric waterpump on the dyno. Are you going to do that too? Remember, everything you run off the crank eats up hp, water pump, alternator, AC. power steering.

[Maverick]

It'll have the belt-driven water pump, power steering pump and alternator. Recall the electric fan was installed, eliminating the belt-driven fan. And, I can remove the AC belt. Other than that, standard belt-driven accessories. Then, there's the auto trans. Engine builder, aka Senior, said to expect about a 20% loss for RWHP. 300 RWHP would be GREAT!!! I'm really eager to get the engine in and try it out. Right now progress is stalled on the exhaust port issues.

WXO & I delivered the 5.0 to Spartanburg and completed that transaction today. Mother Nature was kinder to us today than she was on Thursday when she dumped a few inches of rain on us and the well-wraped 347. We also hauled the engine lift but, with four strong guys we managed to transfer the 5.0 to their pickup without the aid of the lift. 5.0 will have a new life in an '86 Fox Bodied LTD.

[Maverick]

The exhaust ports on the Dart heads are nearly square (with rounded corners). They're wider and shorter than the holes in the head flanges on the Doug Thorley shortie headers. And, the gaskets I bought don't fit either. In some places they would stick out a considerable distance into the exhaust stream. Wasn't looking to do port matching but had to do something about the rediculous mis-match.

Inquiries have been made to Dart and Doug Thorley to get the dimensions of the openings in their gaskets. Haven't heard from them and can't wait.

Thought about champhering both the heads, where they were narrower/shorter than the headers. and the headers where they were narrower/shorter than the heads. But, after looking at the header construction, that seems like a risky idea. The header runners stick thru the flange and are welded just on the ends and then planed flat. Might not take much to break thru the welds.

There are a lot of different size openings in various SFB exhaust manifold gaskets, and one exists that would match the larger width of the head ports and the taller openingsin the header flanges. Those gaskets will be Plan B if a Plan B is needed.

Plan A is done. The gaskets on hand were made to fit the headers so at least they won't be sticking out into the exhaust stream any more than the headers do. The gaskets were bolted to the headers with washers to protect the narrow area around the bolt holes.



The protruding gasket material was trimmed and/or rolled down into the header runner. The left two tubes have had a first pass at the removal and the right two are untouched. Think you can probably see the difference.




Since the shortie headers are probably the limiting factor in air flow, having those gaskets sticking out as much a 1/8" seemed like a bad idea.

Now, back to installing the 347.

[wxo]

What Maverick left unsaid was that he pulled the engine, worked on the headers and put it back by himself and a bit of ingenuity. Nice work, Jim!

[Maverick]

Had some set backs that required some do overs. Yesterdya AM was spent pulling the exhaust pipes back off to get access to the transmission connections for the cooling lines, attaching the lines, and re-installing the exhaust pipes.. Cooler lines have to be attached before the exhaust pipes go on. Then I noticed that the probe that goes into the radiator didn't get installed before IT went in. Did manage to get one step forward yesterday after two back. Did get the aux trans cooler plumbed.

If I every pull that transmission again I'm going to cut the transmission cooler lines so small pieces can be attached to the transmission before it goes in and then splice in the rest with a rubber hose like is run to the aux cooler.

This morning was spent modding the brackets for the offsets for the gauges. Offsets will point the gauges up and left so they're more easily read from the drivers seat. I cut the angles wrong on one and cut another using the supplied template ONLY TO DISCOVER THAT THE TEMPLATE IS WRONG!! Good thing I had to buy extras. The offsets come in packs of 3 and 4 were needed so there were two extras.

Spent this afternood wiring up the engine compartment, napping, playing computer games, and having happy hour.

What I think is the last fitment issue got resolved this evening. The Air Gap intake is 3/4" taller than the Performer that was on the 5.0. The 14X3" air cleaner was not going to fit under the hood. While eyeballing the air cleaner thinking about mods, I remember that I had another base in storage. Pulled it out and ITS A DROP DOWN!! Every once in a while things work out.


I knew that bit ugly AC bracket would come in handy.

[TireSmoker]

After reading your post, it made me realize just how many times I've taken the engine in and out of my Chevelle. Order of operation becomes critical.

I did the exact same thing with my transmission cooler lines that you're thinking about -- except I just used compression fittings instead of rubber hose. But it makes everything easier the next time the trans has to come out.

-Dave

[Maverick]

Had a plan yesterday for WXO to drop by for the first start of the 347 in the car. Its still up on jack stands and plan was to run it there and check for leaks. I say "WAS" because while I was putting coolant in it was running out from the area of the thermostat housing. Had to call of the start.

That had me pretty bummed so I quit but still thought about it, and thought about it, and thought about it. The first thermostat housing I installed, at about age 15, the housing broke as I was tightening it up. Didn't get the thermostat seated in the groove. Never did THAT again. Now I use a rubber band and a pencil to hold the thermostat in place till its bolted in. Shouldn't be the surface on the new intake -- didn't leak on the dyno. Maybe the new housing? Think I've heard about new housings that didn't have a flat gasket surface. Gasket was stuck on well and I'm sure it stayed in place.

Pulled the housing off this morning and found this. Hope it shows in the picture. The gasket hole for the bypass didn't mate well with the intake surface.



Fortunately, I had another gasket -- that fit better -- on hand. Reinstalled the thermostat and housing, put some more coolant in, and it didn't pour out. Will give it a good check for leaks after startup.

After lunch, I'll add more fluids and look for the next do over.

[Fred32v]

Scary, we have all been there. You have to be glad that a new gasket fixed it.
Waiting for the start.

[Basement Paul]

I don't use gaskets any more, just black RTV. Seals everytime, and I always have some on hand.

-BP

[Maverick]

Well, its running, but still some mysteries. With the coil powered thru the resistor wire (approx 8 V), which the MSD Blaster 2F coil instructions insist MUST be done, the engine surges like it intermitently drops off to 7 cyl and picks up again. Pulled the plugs and a couple were wet with fuel.

Tried powering the coil with full 12V and surging goes away but the coil gets too hot to hold your hand on. Don't think it'll last long that way.

I'm not interested in fooling around with it too much since the problem is apparently in the ignition and the Mallory distributor, with electronic ignition, will be replaced with a Pertronix when the car gets back to Charlotte. Just need to get it back there and let the engine builder install the other distributor and set the advance curve.

I may have to buy ANOTHER coil, one that has less than 1 ohm resistance (what the Pertronix dist wants) and will live with 12V. Looks to me like the MSD Blaster 2 was a bad choice. Think I'll just get what Pertronix recommends for that distributor.

Haven't really gotten into it but the engine feels real good!! I'll wait till it has a correct ignition and timing curve to really give it a try.

The 347 is quite a bit louder than the 5.0 was. Sounds GOOD but might get a little monotonous on a trip. Probably an OK trade off.

WXO shot some videos of it idling but I don't know how to post them.

[Maverick]

The engine builder in Charlotte is getting the Pertronix coil that is recommended for the Pertronix distributor. That will be the final (I hope) ignition.

The Sprint will drive to Charlotte with the Mallory distributor and a 12V coil that MUST have a ballast resistor, but doesn't, and 2 similar spare coils in the trunk. I really don't expect any problem for that 150 or so mile trip to charlotte but there'll be 2 spares just in case.

Its running pretty good right now with 12V on the coil. Smoked the tires in first gear. Gonna have to get a better functioning shifter 'cause when I let off a little to reduce wheel spin it up shifted into 2nd too early. Gonna try manually shifting it for a while to see if I can get consistent with the clumsy column shifter.

Primary coil voltage with electronic ignition is really confusing. Conventional wisdom is that a 3 ohm coil can take a full 12V and a 1.5 ohm coil needs a ballast resistor. But, tech support for the Pertronix distributor says it will work with any coil with less than 1 ohm on the primary circuit.

My guess is that the electronic ignitions have a pulse width that is narrower than a points distributor and therefor the coil can take more voltage with increased, shorter-duration current. Anyone have a better answer?

[Maverick]

The engine runs good for 20 min or so and then starte mis-firing in various ways. I've decided not to drive it to Charlotte while its not running well. Asked the engine builder to ship the replacement distributor, matching coil, and new plug wires to me and I'll install them here. HOPEFULLY that will eliminate the cause of the mis-fires.

If THAT doesn't work, Plan C will probably be to install an HEI distributor that I know works well at speed. Nice thing about HEI is it contains the WHOLE ignition. All it wants is a single 12V power source.

Still have to make the trip to Charlotte to return the loaner distributor, plug wires and engine stand. Think, given all the problems, I might want to put it on the chassis dyno they have access to and check it out completely. Would also like to see the torque and RWHP curves.

I've had a belly full of mis-fires!!