new member, from Pa. 1958 348cid

[Harvey Thompson]

hey folks, how is everyone? making some progress, I guess, 2 steps forward and 5 back .... but it will be right and dependable when I'm done. I have another question, I'm fabricating alternator and power steering brackets to mount on the drivers side. I have everything mocked up to where it will be. the issue I'm having is lining up the pulleys. I have 4-5 different pumps as well as 2 boxes of brackets and so on. 2 pumps I have are "key way" pulleys and the others are press on. I've been working with all the different combinations I could come up with and where I'm at now is what I want to use. newer style alt/w/one wire, and a round tank/key way pulley pump. everything mocked up and mounted the pulleys (p/s and alt) are about 1/4" out too far, but I am in as tight as I can go to the block. I spaced the crank and water pump pulleys out 1/4" and everything lines up nice. I don't like the gap between the "stock" dampener and the pulley and the same on the water pump pulley. from some research I've done on here, my understanding is that a 6.75" small block dampener can be used on the 348. my crank shaft did not have threads in the end of the crank where the dampener presses on, I drilled it in appox. 3/4" and tapped it for 7/16" 20 thread bolt. I have 2 small block balancers and want to put one on tomorrow, just wondering if anyone has use the small block dampener and pulleys and what issues you may have ran into. I also have a box of pulleys and just trying to figure out this jig saw puzzle. thks

 

[62impala409]

I am using the 6 3/4" SB balancer on my 409.Be aware that the "W" motor balancer has the key way in a different location than on a SB Chevy balancer. When using th SB balancer and the original timing tab, TDC will be off 10 degress. You will have to remove the old tab and use the bolt on replacement timing tab that puts TDC in the proper location, like this one sold by Showcars. Leo http://www.show-cars.com/cgi-bin/commerce.cgi?preadd=action&key=4786

 

[Harvey Thompson]

I am aware of the 2-10 degree difference and I do have the bolt on timing tab, had to take the original off for the dampener to fit. I need to see what pulleys I am going to have to use. as far as TDC, I can static time it and I have a dial indicator that fits into the spark plug hole to make sure I'm at absolute TDC. as far as timing goes my personal opinion is that no 2 motors are exactly alike ....I will do it like I use to , the book gives you a base to go by, I set base timing, with a vacuum pump I check total advance and take notes. I then let the motor tell me what it wants by setting base timing and then put a vacuum gauge on manifold vacuum, a timing light and then road test it. I turn the distributor (@ idle) until I have max. vacuum (15-20), make note where the timing mark is, then road test under a load, if no "ping" I advance 2 degrees until it pings under a load, back it off 2 degrees until it stops, take note of the reading. I then make sure after I turn it off it starts without binding and adjust accordantly and then lock it down. I've never had any overheating issues and they work fine, no flat spots ect. thks for the input.

 

[oldskydog]

That 10 degree difference is only on 69 and later balancers that were intended for long waterpump engines. Corvette and light truck did not go to long waterpump in 69.
The SB balancer and 348/409 balancer index should be straight up from the keyway.....same as SB pre-69.

 

[Harvey Thompson]

ok, thank you, I appreciate that Skydog. the one I am going to use is off of a 350cid 4 barrel, 4 bolt main motor I have tucked away from a 75 or 85, K-5 blazer, have to double check the castings to make sure of the year again, its been so long ago that I put it away. I'm hoping that the pulleys from the 350 dampener will give me the clearance I need, rough measurements seem to be a lot closer to where I need to be. I was reading some other threads on here and someone mentioned about pulling the water pump flange to where I need it, seems like an option but would be a last resort for me. my water pump has the larger bolt pattern and I do have a selection of pulleys to pick from. I'm trying to keep the alt. and p/s pump as low and as tight as I can, I don't want to have them directly in front of or blocking the valve covers, I want to see the "W" heads with no obstructions, I don't know maybe its just me but I love the look of the motor not the accessories. thks again

 

[oldskydog]

I should have mentioned that trucks went to the long waterpump with the body change in 73 so more than likely that HB will be 10 off. That's not really a problem if you use the matching timing cover/tab.

 

[ron61]

I have experience with SBC engines, nothing on the 'W'. Same principle is used on both for pushrod guide holes in head. Past experience has been if the pushrod is touching the head it will show wear marks, mine are not. The pushrods installed were a mixed batch, some had the pressed in ball ends, some didn't. I installed a new set all with the pressed in ends. Guide holes in head all look O.K.
Lets focus on the rocker arms. What would cause the tips that contact the valve stem to wear excessively? High spring pressures? Poor quality? I tried to do a pushrod length check with a solid lifter and marking the valve tip but it appears the rocker is contacting almost the entire valve stem tip, very wide pattern. I am used to doing this with a roller tip rocker. I also noticed one head has the springs shimmed and the other does not. So assembly quality is probably suspect. These are also early 1958 heads yet the rocker arm studs are pinned, is that something that was done on 409 heads only? Also found wrong length spark plugs installed, had later long 409 plugs. I am worried about the assembly quality again!
I guess the test will be fire it up and see what happens, will not happen soon, dealing with the crankcase vent issues on this type motor. The road draft tube was removed and hole plugged, and nothing else was done for ventilation. I need to install a air/oil separator of some kind in the manifold so I can installed a pcv valve.
Really didn't want to pull the heads off, compression check showed all cylinders to be 135-140, old book I have said 150 is normal, so valves seem to be sealing O.K. That pressure of 150 seems a little low to me but apparently that's normal for low H.P. motor (250).