My first rebuild or The results of my oil pressure concerns

[Mr Comet]

I am going to do this and I know I will need alot of help. First of all when I take the engine to the machine shop what should I be looking for out of the machine shop? They come highly reccommended by my mechanic who has worked on my wifes car and my daughters. I will be getting the head/intake replaced with one from a 73 maverick 250. Anything in the way of modification to the head? This is just for daily driving not racing or alot of HP mainly stock. I have always liked the six because it easier on gas then the V8s but more pep then the 4s. Thanks for your help.

 

[rbohm]

8) when you get the block back from the machine shop, you want to check the deck surface to make sure it is flat. use a long straight edge and lay it against the deck surface lengthwise, width wise in various places, and diagonally in both directions and see if there are any uneven areas. use a very thin feeler gauge, say a .001 or .002. then check the main bearing saddles with the same straight edge to see if they are all at the same level. again use the thin feeler gauge. if the machine shop is any good they will have already checked these, but it doesnt hurt to double check their work.

now chances are that the cylinders will be overbored, probably .030 as that tends to be industry standard. take your new pistons and check the bore clearance. you do this by inserting the piston upside down into the bore, you dont need to go any further down that to cover the ring grooves, and measure the clearance with a feeler gauge, with cast pistons i believe the clearance should be around .004 but check that as its been awhile.

once these checks are done, give the block a good bath with soapy hot water until you can take a white rag soaked with automatic trans fluid and run it through the bores and have it come out clean. at this point, if you are not going to start building the engine, spray the machined surfaces with WD40 or coat them with oil, and wrap the block with a couple of layers of garbage bags and get as much air out as possible before you seal them up to prevent rusting.

 

[Mr Comet]

Thanks for the help. Is there any difference besides the log size with my 67 200 head intake and a 73 250 Maverick head intake? I will be reassembling the engine when I get it back from the machine shop but it's good to know the storage procedure.

 

[rbohm]

8) as to log size, the later head is going to have a large log, but it will also have a large combustion chamber. the large log will allow better airflow, and you can have the head milled to make the combustion chamber smaller. check out the compression ratio calculator at classicinlines.com to determine what your chamber size needs to be and then let the machine shop know so they can mill the head the correct amount.

since you are going to assemble the engine straight away, get yourself a really good assembly lube, royal purple has a very good one, and get yourself some really good cam lube, comp cams is probably the best imo. use the assembly everywhere except on the cam lobes, and be generous with it, you dont want a dry start to ruin your new engine.

you are going to need to prime your oil pump before you try to start the engine. there are two ways to do this, and both work nicely.

1: the old school way is to remove the pump cover and pack the gears with vaseline, then reinstall the cover. this will make sure the pump is primed before you start the engine, and the vaseline dissolves into the oil during break in and never congeals again. i have used this procedure in the past on a variety of engine with no ill effects.

2: the new school way is to take a long hex shaft, about 6-8 inches should do, and chuck it into a drill, and before you install the distributor, run the oil pump with the drill until you get oil up to the rocker arms. this will prime the whole system so that you will not have a dry start when you hit the key. this is best done with the engine in the car ready to fire when you install the distributor.

as i said either way works nicely, and it which you use would depend on how long it will be before the engine goes into the car.

 

[64falconsix]

The later head will also use the 1 3/4" carb inlet. While you have the head off it would be a good idea to do the calculation and get your desired compression ratio or at least what the engine had with the old head. The combustion chamber on the later head will be about 10ccs bigger.

 

[Mr Comet]

Is the combustion chamber the area in the head which for the lack of the correct term is carved out? Or does it include some of the block piston wall? I know the piston upwards stroke is what compresses air and gas mixture prior to firing. The machine shop is going to size up all my internal parts ie pistons to cylinder wall and rings, cam and crankshift and lifters. My lifters fell out in moving the block around . Does that make them unuseable? Then they will give me an estimate. They will do whatever I want them to or leave the assembling to me.

 

[rbohm]

Is the combustion chamber the area in the head which for the lack of the correct term is carved out? Or does it include some of the block piston wall? I know the piston upwards stroke is what compresses air and gas mixture prior to firing. The machine shop is going to size up all my internal parts ie pistons to cylinder wall and rings, cam and crankshift and lifters. My lifters fell out in moving the block around . Does that make them unuseable? Then they will give me an estimate. They will do whatever I want them to or leave the assembling to me.

8) the combustion chamber is mostly the the area in the cylinder head, but it does include the top of the piston, and area between the top pf the piston and the top ring, the head gasket.

as to the lifters, they can be reused IF they are in good shape. chances are though they either need to be machined to new specs, or replace them and change the cam at the same time.

 

[Mr Comet]

I am divided because I do not like to waste almost new parts but I also don't want these parts in the engine if they have contributed to my bad oil pressure. If you PM me your e mail I forward you the invoice of the last so called rebuild. Where can I get the royal purple and the comp cams? How much will I pay for the lifters and cam? Thanks again.

 

[rbohm]

I am divided because I do not like to waste almost new parts but I also don't want these parts in the engine if they have contributed to my bad oil pressure. If you PM me your e mail I forward you the invoice of the last so called rebuild. Where can I get the royal purple and the comp cams? How much will I pay for the lifters and cam? Thanks again.

if the lifters really are alsmost new, then you can go ahead and reuse them. since they fell out of their bores though, and you likely dont know which bore each lifter came out of, then treat them like they are new lifters on a new cam. that means running the engine at 2000-2500 rpm for 30 minutes without idling the engine during that time. that way the lifters will wear in properly on their new lobes. also since the lifters did fall on the floor, check the edges for damage, however slight. if you find any, then take an emory board like women use on their finger nails, and smooth out the damage. and do just the edges nothing else.

 

[bubba22349]

You have some good suggestions for your rebuild all ready. I will add a few more if you use the 73 head check the carb opening if it's not 1.750 then open it up to that so you can then use a bigger 1V carb if you should want to. Swap out the valve springs to a set from a 289 V8. And as was stated check the size of the combustion chambers (CC) you should aim for 9 to 9.3 to 1 C.R. Also you can have the valve bowls opened up and do a good 3 angle vale job with a back cut. Optional if you are looking for a bit more performance install the larger (late model) intake valve and clean up ports (mild porting). On the short block if your master kit dose not include a set of Molly rings upgrade to them. There are a few other optional mods that would be good for a performance build up or depending on how your are wanting to use the car. Like using the Tempo or flat top pistons and or decking the block. Using ARP rod bolts if your rebuild the rods, double roller timing chain set and balancing. Good luck on your rebuild

 

[Mr Comet]

I would like to have a nice running engine which response when the peddle is pushed. Not a hot rod but not a dog. Hopefully something like my old engine which got about 24 mpg on highway. Of course the T5 had a lot to do with the highway mileage. I really do not understand all you said. Is some of the machine work making the head more like the 80s head? I am like everyone else working on a budget so The sky's not the limit. However it makes since to do it right the first time with it all apart and try to anticipate further desires. Need to fire up the crystal ball.

 

[rbohm]

I really do not understand all you said. Is some of the machine work making the head more like the 80s head?

its more like improving the head. some of the 70s heads had the smaller carb opening, and using the larger carb is an inexpensive way to get more airflow into the head, which these engines really need.

I am like everyone else working on a budget so The sky's not the limit. However it makes since to do it right the first time with it all apart and try to anticipate further desires. Need to fire up the crystal ball.

one thing about building these engines is that you really can do it on a budget. since you are rebuilding the engine anyway, it makes certain upgrades budget friendly. take the head for instance. one good upgrade is to increase the size of the valves, going to a 1.75" intake valve and a 1.50" exhaust valve. this increases airflow to the cylinders, and the upgrade is a modest increase in price over rebuilding or replacing what is there already. the nice thing is that you can sell the old valves if they are still in decent shape to help offset the cost of the upgrade, chances are someone here will buy them.

any other questions dont be afraid to ask.

 

[Mr Comet]

I got the 73 engine yesterday, anything special I should need to consider while disassembling the head to take it to the machine shop? Just want to insure I don't mess anything up or cause myself added expense. Everyone have a great weekend. No snow or high water here.

 

[Mr Comet]

Completely disassembled the engine yesterday and today removed the rocker assembly and valves. The carb intake is already 1.75 inch so that is good to go. How do I identify the carb? Looks to have a very large bowl or something between the throat and fuel filter on the carb. The intake valves are 1.625 inch and exhaust is 1.375 so rbohn instructions will be passed on to machine shop. The part number staqrts with D3 so that would make it a 73. 7 out of 11 bolts busted off removing the exhaust manifold so I have already installed a couple of heily coils but still have 5 to do before the head goes to the machine shop.

 

[bubba22349]

My guess by your description is that may be a Carter carb if so they are one of the best in a 1V.

 

[Mr Comet]

Are the head bolts SAE 7/16 NC? I know I removed them with a 11/16 socket which would be 1/2 inch. However when I try to clean the threads with a 1/2 NC die it spins on really easy. The 7/16 NC die only goes a few turns and then it really stiff and I don't want to mess up my threads. Any ideas? The bolts are from my newly purchased 73 250 engine.

 

[Mr Comet]

Is there any difference on a 67 200 timing chain cover and one from a 73 250? Or are they interchangable?

 

[rbohm]

Is there any difference on a 67 200 timing chain cover and one from a 73 250? Or are they interchangable?

i dont believe the 250 timing cover will fit the 200. remember the cam was relocated slightly outward to accommodate the longer stroke of the 250.

 

[Mr Comet]

Second hack so more was lost but i'll pickup where I am at now. The head went on this morning and I learned it is helpful to make two studs to hold the head gasket in place when I slide the head over. I have plenty of head bolts so that was easy enough. Tried a couple of times to try and place gasket on block and then head and found I could not align the gasket and head. studs did that job very nicely. Torgued to 65 lbs I could feel a bit of a spongee feeling when I found the lifters to place the push rods on them. rocker assembly fit right into place nicely also and torgued to 32 lbs. Just put the valve cover on to hand tight in case someone mentions something about my head or rocker assembly and I can second check. Next is the timing chain cover oil pump and screen and then oil pan. Any tips to help with these tasks? Thanks to everyone. Think I should be ready for a weekend engine drop into place in car. Son outlaw will be of great assistance.

 

[rbohm]

Second hack so more was lost but i'll pickup where I am at now. The head went on this morning and I learned it is helpful to make two studs to hold the head gasket in place when I slide the head over. I have plenty of head bolts so that was easy enough. Tried a couple of times to try and place gasket on block and then head and found I could not align the gasket and head. studs did that job very nicely. Torgued to 65 lbs I could feel a bit of a spongee feeling when I found the lifters to place the push rods on them. rocker assembly fit right into place nicely also and torgued to 32 lbs. Just put the valve cover on to hand tight in case someone mentions something about my head or rocker assembly and I can second check. Next is the timing chain cover oil pump and screen and then oil pan. Any tips to help with these tasks? Thanks to everyone. Think I should be ready for a weekend engine drop into place in car. Son outlaw will be of great assistance.

nice job making studs to help hold the gasket in place. i knew there was a tip i was forgetting to give you.

and as you found out, knowing when the push rods are in the proper location was easy.

as to the oil pump, and by rote the distributor, install the distributor first. that way the gear is meshed with the cam, and when you go to install the oil pump drive shaft it will be MUCH easier.

for installing the oil pan and the timing cover, i like to take the gaskets and out a THIN layer of rtv on both sides of the gasket, and then install it and the timing cover and oil pan straight away. you dont want to over torque the bolts. tighten them up until you see the gasket start to bulge slightly and stop there. one other thing, check the gasket surfaces on the timing cover and the oil pan, especially around the bolt holes, to ensure that they are clean and flat. if you have to massage the bolt holes to make them flat, use a small hammer and go easy with it, you dont need to pound it like a stuck kingpin. you just want to encourage the metal to lay flat again.