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400 SBC question.

K5Titan83

K5Titan83

1/2 ton status
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Sep 26, 2013
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Location
Missouri
okay the other day I went to taking apart my engine I bought I new bigger cam for it me and a friend of mine was going to install, well got it all taken apart and went to pull the old cam out of it and noticed the front cam bearing moved slightly, im thinking "oh ****". anyway got the cam out and sure enough the cam bearing as been spinning, i don't have the engine completely out or taken apart yet so all i can really see is the front bearing. i can take my fingers and push it out and into the block but i cant pull it out of the block, so i guess its kinda mushroomed in its hole. my question is can a 400 small block chevy be line bored and have over sized cam bearing installed? i was told they might not have bigger cam bearings for that and the block may be done with. :confused:
 
I'm not real familiar with this stuff anymore like I used to, but it's the same cam and bearings as a 350 and would think they can put oversized bearings in. Worst case, you need a new block, I would get a 350. But I'm biased, my 406 was a pile of junk, always ran/got hot.
 
mines a built 409 and i had my heads drilled for the steam ports and what not and she still ran kinda hot until i out in a brand new radiator and ran a 185 thermostat then she still only ran just over normal lol, but if it turns out the block is bad i will go with a 350 block and use what i can off my 400 which is just about everything but the pistons., however im betting it has to be bored fairly large to get rid of the muchrooming thing its done and idk how big it can be bored till we cant get over sized cam bearings
 
If you are going to replace the block, look for a roller 350 block, and ditch the flat tappet cam.

Martin
 
K5Titan83 said:
mines a built 409 and i had my heads drilled for the steam ports and what not and she still ran kinda hot until i out in a brand new radiator and ran a 185 thermostat then she still only ran just over normal lol, but if it turns out the block is bad i will go with a 350 block and use what i can off my 400 which is just about everything but the pistons., however im betting it has to be bored fairly large to get rid of the muchrooming thing its done and idk how big it can be bored till we cant get over sized cam bearings
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I had a 4 row big block radiator, dual electric fans, 160 stat, and it would still sit at *210. If it was hot outside, *220. Hook up to a trailer or anything, and the sky was the limit.
 
K85 Octane said:
and throw the 400 crank in the 350 :D
Click to expand...

Exactly what I was thinkin! :waytogo:

rjfguitar said:
I had a 4 row big block radiator, dual electric fans, 160 stat, and it would still sit at *210. If it was hot outside, *220. Hook up to a trailer or anything, and the sky was the limit.
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Iv just been running a stock radiator, and I had a single electric fan for mine as well but I found a stock clutch fan seemed to work better for me, Im right around the same temps you were at but I never pull anything with mine so Idk what it would do then. so maybe those steam ports in the heads did some good after all.
 
K5Titan83 said:
Exactly what I was thinkin! :waytogo:



Iv just been running a stock radiator, and I had a single electric fan for mine as well but I found a stock clutch fan seemed to work better for me, Im right around the same temps you were at but I never pull anything with mine so Idk what it would do then. so maybe those steam ports in the heads did some good after all.
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Without steam ports I don't think a 400 will even stay cool at all. Mine did seem to be one of the worst 400's I can recall here on CK5. Many guys didn't have heating trouble, or was milder like yours.
 
Hmm.
I dont run steel holes on my 400s anymore.
As far as running hot I've yet to have one. Maybe im just lucky. I daily drive mine now, blast down the highway. Its my around town commuter. Any day hot or cold out same temp. With stock fan and shroud.
If a cam bearing spun then maybe soemthing nay have caused it or it was installed wrong by the last guy who put engine together
 
63chevyll said:
Hmm.
I dont run steel holes on my 400s anymore.
As far as running hot I've yet to have one. Maybe im just lucky. I daily drive mine now, blast down the highway. Its my around town commuter. Any day hot or cold out same temp. With stock fan and shroud.
If a cam bearing spun then maybe soemthing nay have caused it or it was installed wrong by the last guy who put engine together
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yeah I was talking to a friend of mine and he said with the 400's you never know, hes had some he couldn't get to not over heat and some that ran like yours just fine no matter what. but anyway, I got the engine out and kinda taken apart I think im going to use a different block, that same friend of mine whos been messin with these things forever thinks that the block has been twisted. theres a few things about it that hes noticed and im just not gonna take any chances of putting gobs money in something like that. so im just gonna start looking for a 350 block and use as much stuff off my 400 that I can and have the block reworked.
 
I think your camshaft journals could be just fine. You just have worn out cam bearings. I have taken apart engines with a lot of miles on them, and had every single cam bearing fall out because this what worn out cam bearings do.

you could try buying a set of new cams bearings, and install the one you need in the front cam journal. This would not be 100% easy because you have to be very careful to install it without damaging it, and installing a cam bearing while an engine is still in the truck would not be a simple task, or are you intending to take this engine out of the truck?
 
1-ton said:
I think your camshaft journals could be just fine. You just have worn out cam bearings. I have taken apart engines with a lot of miles on them, and had every single cam bearing fall out because this what worn out cam bearings do.

you could try buying a set of new cams bearings, and install the one you need in the front cam journal. This would not be 100% easy because you have to be very careful to install it without damaging it, and installing a cam bearing while an engine is still in the truck would not be a simple task, or are you intending to take this engine out of the truck?
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yeah the engine is out of the truck now. but theres some more things wrong with the block and im just over it haha. iv got an old 93 suburban and I think I can use the block out of it, have it reworked to use basically everything out of the 400 in it.
 
82355 said:
Are you gonna go roller cam then?

Martin
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no probably not. iv already bought a new cam and lifters that I was going to use in my 400, we were in the process of changing it when we found the cam bearing. so im just going to use what iv already got.
 
I have had great luck with several 400's. So don't scrap that one, sell it to help pay for your swap! I have sold a couple 400's that were tired stockers for $200.
 
6872xtc said:
I have had great luck with several 400's. So don't scrap that one, sell it to help pay for your swap! I have sold a couple 400's that were tired stockers for $200.
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yeah that's what im going to do, im sure someone will wanna mess with it. iv got the truck heads that were on the block when I got it still and the cam that was originally in it.
 
does anyone know if the dashboard out of a 93 chevy suburban will fit in an 83 k5?
 
I would unload that cam. It seems silly to use a roller block, and not take advantage of it.

Martin
 
K5Titan83 said:
yeah that's what im going to do, im sure someone will wanna mess with it. iv got the truck heads that were on the block when I got it still and the cam that was originally in it.
Click to expand...
I thought about selling my 400 long block after I pulled it, but changed my mind. I wouldn't want to do that to someone. I'm going to do the world a favor and throw mine in the garbage.

I apologize... I spent a lot on my 400 getting it built, then a bunch more trying to figure out how to keep it cool with basically no success, so I was left with a pretty bitter taste in my mouth. Especially after getting my 6.0L installed, the 400 would have both electric fans going full speed with it just idling and would be 210*, my 6L can sit there and idle and one fan cycling on a slow cycle keeps the thermostat wanting to open and close.
 
82355 said:
I would unload that cam. It seems silly to use a roller block, and not take advantage of it.

Martin
Click to expand...

I might be wrong but i don't think that block used a roller cam, its a 93' TBI350, I don't think they started using roller cams in them till the vortecs did they?



rjfguitar said:
I thought about selling my 400 long block after I pulled it, but changed my mind. I wouldn't want to do that to someone. I'm going to do the world a favor and throw mine in the garbage.

I apologize... I spent a lot on my 400 getting it built, then a bunch more trying to figure out how to keep it cool with basically no success, so I was left with a pretty bitter taste in my mouth. Especially after getting my 6.0L installed, the 400 would have both electric fans going full speed with it just idling and would be 210*, my 6L can sit there and idle and one fan cycling on a slow cycle keeps the thermostat wanting to open and close.
Click to expand...

iv also spent a lot on my 400, but im still gonna try and sell it, im gonna tell em all that's wrong with it and if it sells it sells if not il scrap it or use it as a big paper weight haha. but I can understand your frustration to with all that youv had to go through with yours
 
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