i will go check it right now, they look like the right ring. for example, you said that you had a 1/16 ring and was supposed to have a 5/64, I would assume that you could tell the 1/6 ring was to small for the ring land by looking for it, but if you weren't, i can easily see how it could be overlooked.

 

I have .003 clearence, I can't fit a .004 in there. To tell you the truth, that's one thing I never checked when I built the engine.

oh, I didn't mean to come off as a jerk in my last reply, in no way was I trying to imply that you were an idiot for putting the wrong rings in your pistons. I apologize if you took it that way. I would never do that. I appreciate your help along with everyone elses help, input and intrest in my thread.

:hail:

 

it's not immediately obvious, i mean we are only talking about 0.014" or so if the rings are the wrong size.

i just had SO many of the same symptoms as you, and the same comments about the engine, and thought i might never find problem / just rebuild it and it would go away...but it's certainly much more confidence inspiring to find the problem and know it's fixed!

 

Yeah I bet so, I am afraid of putting it back together and hope it works this time. I can see how .014 could be over looked, that's not very much at all.

thanks again for all your help.

 

LilJayV10 -

Too bad the machine shop didn't see any "smoking gun" - excuse the pun. But I see you're doing it right. Good idea taking the heads to the shop also. In essence, I'm running the same course you are with yours, except for slight scoring on mine.

Just had it re-honed, had the heads checked out also and everything seems OK....so I guess we'll both see how it goes.

Don't let it bother you too much that you didn't find anything. You have the same opportunity I have now. Ensuring everything is right as it goes back together. And thanks - I'm pretty confident I'll have no problems getting the engine back on the road. Good luck!

 

Well, I found out what was wrong. The block checked out good, it was rehoned, piston wall clearence is ok.

To make a long story short, I put the freakin 2nd ring in upside down. It was sucking oil up from the crankcase, then forcing the compression into the crankcase instead of in the cylinder.

I was talking to one of the old guys that works there and he asked me if I had put the rings in correctly, I said ahh yeah I think I did. So we pulled the rings off and the dot was at the bottom not the top. Let me tell you, I caught a lot of hell from this and I imagine I will for a while, but thats ok, I messed up.

I did find out however that I had a blown headgasket between cylinders 3 and 5 on the block side. They put a straight edge on the block and said it's fine. I don't know if it was detonating so bad because of the oil in the combustion chamber that it was reaking hell on the fire ring or what. So I am going to have the block decked, which I didn't do before(which I should have) and have the heads resurfaced. I am going to find out the deck height so I will know exactly how much compression I have and will deck the block accordingly. I think I might also have the main's aligned honed, they have the machine now and I might have that done. Since I don't have a job right now, I won't be doing much of anything with it.

It was my fault, but atleast I found out what the problem was so I can stop worrying about it.

Mike said hey, you thought the thing ran good before, think how good it will run with the compression staying in the cylinder.

 

Are/were you using the fel pro 1014 gasket, the one with 4.200" bore and 0.039" compressed thickness? If I remember correctly, you have aluminum heads; the fel pro 1014 is one of the few out there with steam holes for a 400 and aluminum heads ..

anyways, mr gasket makes a 0.038" thick gasket for the 400, that has 4.190" bores ... in other words, it has 0.020" more material between each cylinder. It's not much, but it's a little extra between those already-close 400 cylinders and might help reduce the odds of any future head gasket issues between the bores. It's part # 5801. It was the best gasket I could find for 4.155 bores, aluminum heads, WITH steam holes. There is quite a few 400 head gaskets out there without the steam holes!

Also, if you do align hone the mains, i think you need a special rear oil seal on the 400. Mine didn't need it (it measured fine and we skipped the align hone), but I did read about it somewhere, being some special kind of seal for the 400.

Anyways, hope that's helpful. glad you caught the problem.

 

That's great news LilJayV10!

It's a bonus to positively ID the problem. And yeah, the dot side is always up because it has a beveled edge....sh*t happens.

Not quite sure why you're having it decked and align honed though. Unless it really needs it. I think it'll run nice with a properly installed set of rings!!

EDIT: Oh BTW 91L98Z28 - I think I just got the 1014 (or 1017) fel-pro gasket from Jeg's. I know it's a 4.200 bore for a "Marine" 400 which means it has steam holes from what I've heard...and yeah, compressed thickness of .039....I think that's what mine had - but I have iron heads....

 

Yeah I feel like a dumbass. I have iron heads, protopline 220cc w/ 2.05/1.60's.

I will have to do some checking on the head gaskets.

The reason I am going to have it decked is because I want to make sure I don't have any other head gasket problems especially with the rings seating and the increased compression and so I know exactly that compression I have.

Unless I have the extra money laying around, I will really doubt I will have it alinged honed.

As far as the special seal for the 400, Mike at the machine shop said something about the 400's which have the larger mains but uses a 350 rear main seal, he said on the rear cap he has to machine something out so he can aling hone it. I might have not gotten all that right but it's somewhere around what he said.

 

I think you only need the bigger rear main seal if you have it aline bored not just honed ..
I had to have mine bored (for the splayed billit caps) and it needed the different seal.. can't remember the # of it though

 

If there is any scoring then its so small that you cant see it very well. This small amount of scoring would cause a problem thats probably what you machine shop noticed. If you dougt them then take it to another shop and see what they say.

 

The problem wasn't with me or the machine shop seeing the scores in the cylinders really...

It's just that it's hard to see that in pics.

 

Liljayv10 skip the aline honed and you do need a differnt rear main if you have it honed. I would have it zero decked.

 

Just thought I would see how everyone's doing, how their projects are going and such. I got a new job, I'm the fleet mechanic for the ambulance comany here in town. I have finally gotten the fast paced high stress job I was looking for.
Because of all the hours I have been working I think the 406 is going back together next month. I am going to have the block decked and thats it. I'm going to get new head bolts but and not going to have it aligned honed. I don't see the benefits for it.

I am going to have the my protopline heads flowed to see how they compare to the advertised numbers, I know there was a bunch of talk about the actual numbers for the protopline heads.

I am keeping everything he same, except this time I'm going to install the rings the correct way.

Then I am going to have it dynoed and see what numbers I put out. Future plans for the engine this summer are dual 3 inch exhaust, and try a single plan intake, some build ups I've seen pick up a bunch of power, and others loose a **** load of tourqe, we will see. It will be nice having the car and it not freakin smoke constantly. I still can't believe I did that, I obviously looked at the instructions wrong.

The only other thing I might do is put 3.42 gears in it. I am undecided if that is going to make any difference in my ET. I don't know.

Now that I have a "real" job as my friend kevin says, I will be able to do a lot more to it. But overall I am happy with the combonation. It ran 7.8's on radials with a 3.23 gear and the rings upside down and it's 100% streetable. I don't see any reason to make it unpleasant to drive. If I race something faster thats running 7.5's in the 1/8, I don't need to be racing it. Yeahh right.

Any idea's on how much power I will put down on the dyno?

 

i've had my new non smoking 406 to the track once myself.

motor is in the second car in my sig. close ratio muncie, 3.31 gears, NON-positraction rear. no real performance tuning has been done - stock 3310 holley, about 34* total timing. air cleaner is half inch above the choke horn. things aren't real optimum. but what the hell. i wanted to see what it would do.

on the first run we went 13.7 @ 107 short shifting at 5500 and with an easy launch (2.4 60ft). I just wanted to get down the strip.

second run I tried to get any kind of decent 60ft and failed (no posi, sagging rear springs, junk rear shocks, not a good combo) and ran a 3.0 60ft. i tried shifting at 6200 but the motor sucked the carb dry in 3rd gear, so packed it up and went home.

once I get the fuel system fixed, and traction, i figure I can break into the 12's easy. Since there is fuel problems, the car is probably leaning out (which has to be costing me HP) as the carb bowls drain. then have to tune on the holley and get the secondaries to open faster, some 3.73's..

even though my 406 will "only" be a 12 second motor, the thing that i'm happiest about is it's TOTALLY drivable. it's a total pussycat in stop and go traffic. i dare say it's just as easy to drive in stop and go traffic (if not easier) than a stock TPI motor.... the torque right off idle is just awesome.

I figure if I ever need to go faster, I can dump the fastburn heads and get some AFR's, and perhaps a bit more cam. the first generation GM fast burn heads (which I have) have a pretty weak exhaust port, oh and i'm running only 1 5/8 headers and a flowmaster crossflow. that's got to go too!

 

could you ues a smaller .960" base circle cam to provide extra clerance
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could you use a smaller base circle cam like a .960" to get the clerance you need

 

LilJayV10 I havent made many post on the site being new and all, but I really like this thread. Its the type of thread someone can really use when doing a build. ( thank you for those who have had good input to ). The step by step is great and very informative. You mentioned at the begining about side clearances on your rods, from everywhere I have read the normal tolerances ( for a 350 anyway ) was between .012 and .025 I was wondering what yours were if you can remeber. Im in the process of building a mild 355 and mine came right in at .012 I was thinking that was pretty tight but was asured by my mechanic it would be fine.

 

a .012" means he is a decent builder. try to take it easy for the firt couple hund miles or so...a .018-.020 is a race otta the box but lower oil press and lower longevity motor. nothing is right or wrong here.

 

Thats good to know, Thanks.

 

I don't know the answer to that. I think if I would have used rods with cap screws instead I would have been ok. I didn't have to grind that much off.

 

I ran a small base circle cam in my 406 and had no cam/rod clearance issues.

using standard 5.7 rods.

might have to use custom length pushrods with a small base circle cam, though.

FYI