dejh22

Dan looks awesome!

Thank you. The previous owner had a "Machine Shop" build the engine for him. I saw a video he took of the engine running with the caption "Breaking in the new cam"! By the sounds of it, something was "breaking"! I feel sorry for him really. He was so frustrated with the whole thing.

This is what happens when you run 3964290 closed chamber heads with open chamber domed pistons. Almost all the valves where hitting the pistons. With the combo they put together I think they were close to 12-1 compression. I think flat tops would of been a better choice! We have a replacement block and a set of open chamber heads with some small dome open chamber pistons. This engine is going back in a 70 Monte Carlo my son bought while he was home this summer.

The fan should be inside the tunnel. I run a flex fan with a 2" spacer. I have the correct big block shroud with the tunnel. The tunnel is the same on small block and big block. I'm running a 180 thermostat. On a hot summer day my big block will run at about 190. Let me add that I just rebuilt the engine a year ago.

Do you have a fan shroud? Do you have the bypass hose installed?

Here. I think these are it. if Dan doesn't have any. https://www.ebay.com/itm/1968-72-GM-A-body-Chevelle-GTO-442-GS-Rear-Upper-Seat-Bolts-Washer-2pc-OEM/392089851970?epid=1651222344&hash=item5b4a605842:g:WUcAAOSwjNZbWkbI&vxp=mtr

OOPS! Sorry. I misread it.

Here is a link for you. https://www.ebay.com/itm/GM-SEAT-BELT-BOLT-1-1-2-LONG-FACTORY-CORRECT-GRADE-8-GOLD-CAD-PLATED-1pc-GM/161113363914?fits=Year%3A1970|Model%3AMonte+Carlo&epid=1334185907&hash=item25831ad5ca:g:gXgAAOSwRgJXhlfW&vxp=mtr

Would that be a 292 comp cam? We will be using that cam on our next build. What heads are you going with. 049 781.820? The last engine we did was a 396 with L2242 pistons with 38 CC domes and 820 heads. The 820's are 113 cc chamber. This combo gives us about 10.25 to 1 compression. It has the 280 comp cam. Just got the 396 running again today. Seems the machine shop had a bad batch of valve guide seals and the engine was a little "Smokey".

How many miles on the engine? Can not tell by the picture is it "sticky" or is it "sooty"? Could be a carb running rich or valve guides or valve seals. I'm been dealing with the same problem. I pulled my intake only to find puddles of oil in most the head intake ports. So I just pulled the heads and back to the machine shop they went. The engine only has a few hundred miles on it. We are thinking a problem with the valve guides. Will know for sure in a couple days.

Heads are off and going to be installing another set after I have them gone thru. We believe it is the valve guides leaking past the outside of the valve guide (between the guide and head).

I was told that the aluminum heads are taller where the valve cover sits. The lip around the top is raised. I do have the aftermarket Edellbrock valve covers. If this is true I won't be able to get the cover on. Smaller booster like you said might help, Sorry I wasn't more clear on the original post.Thanks for the reply.

Just wanted to know if anyone is running aluminum heads on their big block? I'm asking because the stock heads I have now the driver side valve cover is a tight fit because of the brake booster. Thanks

Another update. I pulled the intake and looked down into the intake ports of the heads and found small pools of oil in all cylinders except one and two. This has me stumped. The heads don't have very many miles on them. They are iron heads ( 3993820 ). I read somewhere that the rocker arm studs can protrude into the ports. That they found the studs had no sealant on the threads and oil was leaking past. I know that on aftermarket heads this can be true. I didn't think the rocker arm studs on stock big block heads did.

I went ahead and just lined them up. I did add just a little rtv. Went back together good and doesn't leak anymore. I now have to figure out why it smokes a little and the oil smells like fuel. I have been in touch with my machinist and he trying to help me figure out what could be going on. Oh plus I noticed the water pump is leaking.

Update.... I just did a wet compression test on a couple cylinders. #1 dry was 180 and wet 190 #7 dry was 170 and wet 180. Could it be I just need to put some more miles on it to see if the rings will seat?

Well I just replaced the rear main seal so the old oil is gone. But I remembered I changed the oil filter and it was still out in the garage. So I poured the oil from it into a cup, I tried to smell it and I could smell anything. I had a couple other people smell it and they said without a doubt it smelled like gas. This engine is a true 396. My machine guy said it was in specs and could keep it standard bore. But was on edge. I went ahead and kept it standard. This is the first engine of have done without having it punched. It really didn't smoke at first start up. But then it started smoking both sides and then went a away. My thought was I need to get some miles on it and seat the rings. Then it would smoke on and off. This last time it would smoke all the time on the left side not a lot. There isn't very many miles on it, I would say less then 500. It really does run great. I think What I may need to do is pull it and bore it .030 over. Like I should of done in the first place!

UPDATE, Rear main has been changed and not leaking as of yet. I also changed the transmission modulator that was bad. I was hoping that was the cause of the light smoke on the LEFT side. ( The Topic says right side, my bad) The light smoke is still there. Tonight I did my first ever compression check. Here are the results. 1. 180 3. 175 5. 170 7. 170 2. 180 (little less) 4. 180 6. 180 8. 180 As you can see the lower compression side is also the side that is smoking a little. What should this be telling me if anything? The engine doesn't run hot. I really don't think the smoke is from coolant. I had someone tell me it smells like fuel and they also said it smells like oil. I have Parkinson's and don't have a sense of smell so I can't tell. The color of the smoke is a blue/white color. Thanks

Well I couldn't take it any longer. The rear main seal started leaking more so I decided to replace it. Last fall I was convinced it was the oil pan gasket. I wish I would have replaced the rear main at the same time. The seal on the bottom looks to be the problem it is a little long on one side. The seal on the top was flush with the block. I would of thought my guy would of caught this. This was the first time I had him do the short block. I just need to clean everything and wait for the new seals to show up.

I adjusted the carb yesterday. But I think it is about set were it was. The spark plug wires are new and in good condition. I'm running a 750 Holley vacuum secondary. It has a comp cam 280H It has a 520 lift 280 duration. The compression is about 10.25 - 1. It runs really well

Well it does have a small rear main drip. So it does use a little oil from that. Just going to live with it for now. I did find trans fluid in the vacuum line from the trans vacuum modulator to the vacuum port on the carb. So I'm thinking that might be the source of the smoke? Was just getting ready to order a new modulator online.

I'm having an issue with a 396 that was rebuilt last year. At first before I dialed it in, it was smoking on the left side. I had colder plugs (AC 44's) pulled them out and they were wet and black. After tuning and replacing with a hotter plug (AC 45's) plugs looked better and for the most part the smoking went away. I have been driving it some this spring and even went to a couple car shows. Been noticing some smoke again on and off but this time on the right side. Drove it last weekend and did not notice any smoke. My friend said it smelled like "gas" when I passed him. Today I went to a car show and just got home. I noticed it smoking a little again on the right side. I backed it in the garage and my wife said it burned her eyes. The smoke is a light blueish color. I just pulled the plugs on the right side and they look good to me. Starts good and runs good. Could it just be rings not seated yet? I don't think it even has 500 miles on it. Here are some pics of the plugs.

Thanks for the info. I tested the gauge with the method of grounding the brown hot wire that went to the sending unit. It did as described it would do if the gauge was good. Could it still have a bad capacitor?

I went out this afternoon and emptied the gas tank. I'm sure I did not get it all but most of it. Checked the gas gauge and it showed about a 1/4 tank past empty. So I'm guessing something is up with the float.

I know this has been discussed before and I want to see if anyone has had the same problem. I had a problem with my fuel gauge reading over full. Last fall I installed a new fuel sending unit and all seemed to be ok after adding about 5 gallons and the gauge showed about a 1/4 tank. This spring I went up to the gas station and filled it up. The gauge only showed about a half a tank. So now I'm wondering if the new gauge is faulty or maybe it is hanging up and not able to register full?