Thread: 350 Build

Tweet

65ny is correct about the ignition timing. A truckload of cam calls for a truckload of timing.

You didn't say what converter is behind the 327, but I'll assume a stock one. Using a stock converter will require some ignition curve, while a looser (3000-3500) converter could allow locked out timing with no centrifugal advance.

I always try to fix things with the least amount out of pocket, so let's proceed along that line. Get an ignition re-curve kit from Summit or wherever. Put 16 degrees of centrifugal advance in the distributor. Find a local shop with a distributor machine and set the dizzy for 16, all in by 2600-2800. Set the initial timing at the crank at 20 degrees. 20 plus 16 will give you 36 total. If the motor tries to kick back against the starter because of all the initial advance, install a momentary-off pushbutton that breaks the circuit on the wire going to the coil. Mount it on the dash or wherever you can mount it in the cabin. Push the momentary button to kill ignition while you turn the key to spin the motor. Once the motor is spinning, release the momentary pushbutton and the motor will fire. If you had a very loose converter, I would suggest locking out the centrifugal by using small tie wraps on the centrifugal weights to cinch them at zero and use 36 degrees at the crank with the momentary switch.

This is only a stop-gap operation to get you operating with the 327 until you can either find time to change the cam in it or build up a mild-mannered 350. I wish I could have gotten to you before you laid out money for another flat tappet block. Here in Phoenix, in the last 3 weeks, I've seen two rebuildable roller long blocks on craigslist for under $200. If you put the word Vortec into the search under auto parts, you can find these motors. The ideal one to start with is the '96 to '98 5700 Vortec from a Chevy truck. That motor will have the L31 Vortec heads on it and it won't get much better than that for a starting point for a streetable 350 or 383 build. The motors I called about still had the roller lifters (re-useable), dog bones and spider. One of them was a 4-bolt block.

I'm just including this for others on the board. DON'T EVER BUY ANOTHER FLAT TAPPET BLOCK TO START A BUILD WITH.

FMX, do not buy heads or cam or anything else from ANYWHERE until I see pics of the pistons and you measure the piston deck height.

Sounds good guys, I appreciate the help! The reasons I will not use the 327 is because even though the previous owner said it had "probably" (were his words) 20,000 miles or less, I still dont trust what other people say and do not plan to get this car stripped, sand blasted and COMPLETELY gone through and painted and find out the motor doesn't last but a year or so on me. Also it's a 69 block and there are no mounting holes in the head for my A/C conversion and power steering conversion which I am sure can still be done but with expensive mounting brackets.
I will first get some pictures of the 350 for you and have you tell me what you think about it. I'd like to use the 350 already since I have it torn down and I will know my own cam and head setup on it. If I keep this 350 then I may just keep the heads that are on it and just put new lifters and push rods in it with a spring kit and be done. Like I said, I want a reliable daily driver out of this car and a big cam is not going to help with that and fuel mileage. As for the exhaust, it's not leaking it's just that it turnsdown under the car near the rear doors/rear end and it is a little black but mostly just raw fuel (BADLY). This was done by the PO and it's something I am changing. I dont need exhaust fumes comming back into the cab and plus it's much too loud for a daily driver.
Before we go any further, let me get those pictures posted up here sometime today with the head information and block information. Now with the deckheight how should I measure this?
As for the 327 and powerglide, I dont mind pulling it and not using it because I have a long future plan of building a T bucket in the next year or so and have been gathering parts for it for a long time. I was first going to use a 302 motor in it but I didnt have a Ford tranny for it but now I have a Chevy combo, S10 rear end, fuel cell and a bunch of other parts to get a T bucket going.
Thanks again guys!

Do you own a dial caliper?

Tech,
No I do not actually. Wish I did but most of my tools I have are for detailing or auto body. I really need a set of calipers because there have been numerous times I've needed them.
I also do not know about getting the pictures of the engine today but am still going to try to here a little later and post them tonight. If not then it will be Thursday before I post them.

OK, when produced at the factory, blocks are cut with a nominal block deck height of +/- 9.025" (centerline of the main bearing bore to the block deck where the head bolts on). This assumes that the block has not been decked by some knot-head before you got it. Adding up your stack of parts will tell you the piston deck height and the gasket to use for a tight squish. 350 crank radius of 1.74" + 5.700" rod length + 1.560" piston compression height = 9.000". Theoretically, this would leave a piston deck height of 0.025", which, together with an 0.015" head gasket would produce a squish of 0.040".

However, don't assume anything. Always measure your clearances before final machining and assembly. You still have the pistons in the short block and that's good. With the motor on a stand, tilt it so that one bank is level. Using a steel rule and a set of feeler gauges, we'll find the actual piston deck height. Standing at the side of the block, span the edge of your rule across the bore about 1/4" from the edge of the bore at either the 3 oclock or 9 oclock position of the piston. Slide feeler gauge blades between the bottom of the edge of the steel rule and the piston crown. Checking the piston at noon or 6 oclock will allow the piston to rock on its wrist pin and tilt one way or the other, giving you an erroneous reading. 3 or 9 is directly above the pin. Rotate the crank a few degrees backward and forward and re-check your measurement to make sure the piston is at TDC. If you find a piston deck height of 0.020" to 0.030", you'll be fine with an 0.015" steel shim gasket (assuming the block decks are smooth and parallel). Do this measurement on each of the four corners of the block to see if there is a slope to the block front to rear and/or a difference from one bank to the other that would require cutting the block decks to correct the fault.

Tech, again you have helped me a lot here and I will go ahead and do this whenever I can get a buddy with tools over here. I have no engine tools such as micrometers, dial calipers, bore gauges, etc etc. The tools that you are speaking of, where should/can I buy these at? I was looking at Summit and see they have quite a variety of tools but not sure how good they are. Instead of borrowing a friends of mine I wouldn't mind buying my own because I really need them for other builds that I have planned.
As for the pictures, it just didn't happen tonight. The engine is at my parents house and I have been gone a lot lately and need to get over there to get the pictures, then bring them back to the fire department and use their computer to post them here so it is a bit of a hassle and I have been studying for my finals in a personal finance class at the local college. The final exam is tomarrow so I will be busy with that all day and tomarrow night I will take them and post them on Thursday. I will get some close pictures of the cylinder walls, the tops of the pistons and underneath as well. Like I said, I pulled the heads, oil pan, water pump, fuel pump, etc. The water pump was noisy so I figured I might as well replace all of this and know that it's all new and in good working order.
I am very picky as far as engines go and wanting to make sure I know everything that is in them and that it's all done correctly and no corners cut. One thing I will do tonight is order a SBC engine building book on Amazon.com There is one that I have to find that a friend has and said is old but very good and explains the basics of measuring and assembling a sbc.