anyone know of any actual known case of a cracked 87 tbi 305 tbi intake or heads ?

just curious as i have an 87 with TBI 305 its burning water alot and i need to fix it asap,

hoping that new head and intake gaskets and milling the heads a little does the trick and that theres not a possible cracked part

it did run hot and water in oil




thanks

 

It could just be a bad head gasket.

 

hi thanks well yeah but i was wanting to know if anyone ever has experienced a cracked head or intake on these TBI 305s

wanted to make sure before just replacing gaskets

have no way to check for cracks, only have one shop here and they cant check for them,

so..

can mill heads though
which i will have done to remove any warpage,


so if anyone knows of any confirmed case of cracked tbi 305 head or intake then lemme know


thanks for anything else

 

One of the most common reasons for losing coolant with TBI is that each intake manifold gasket (manifold -to- head) will often get tired and begin to leak coolant. This is especially common above cylinder #1 (driver's side front) and #8 (pass side rear) and you can often see telltale signs of greenish brown coolant residue there.

You can inspect where the intake manifold attaches to the heads and look for evidence of the above. You might only need to remove, clean, replace the offending gaskets. Read up on the proper procedure to seal the china walls before you do it. HTH.

 

yep there is a bunch of that greenish powdery residue up on intake, especially on the front driver side corner of the intake by those two bolts right there,

this engine had alot of water in the oil and was known to have been run hot

do you think that just the intake gaskets being toast could/would be a lone cause for this ?

by chance ?

or definitely be head gaskets problem too ?

i was thinking that maybe water ports of intake could leak into lifter gallery ?



and china walls ? you mean the front and back walls of the block/lifter gallery?

or something else?


ive never heard the term 'china walls' associated with sbc engines
before


thanks

 

That's #1 cylinder, which is one of the trouble spots I mentioned.



Could be, yes.



Check the compression in each cylinder with a screw-in compression gauge.



It's not a likely place for a crack. It's more likely that the gaskets are tired.



Yes. They don't seal coolant at all, but they do seal the intake manifold front and back to the lifter valley, and you want to make sure that these areas don't leak oil if you pull the intake to replace gaskets (and to check the intake for the crack(s) you suspected.

 

hi thanks

number 5 cylinder had soem antifreeze come out of it when i was turning engine by hand to set engine to tdc #1

i got the intake off today

the intake has already been off before i can tell because it has the blue fel pro gaskets and orange RTV on the china wall tops


the engine was frozen real good at first i had to break it loose with breaker bar, but it turns fine now, it was sitting for about a month and a half, since i last ran it


but now i have another problem!

lol..


i was checking out the distributor(1103698) after pulling it and it is really hard to turn by hand, something is wrong with it, i went on google and searched about this distributor and came up with this page:

http://www.mightyautoparts.com/pdf/articles/tt71.pdf

this is not welcome news/info

youre supposed to be able to spin the shaft by hand and be able to feel if the magnets and points grab or not, but well this distributor must be extremely gummed or FUBAR, as it really takes some real effort to turn the shaft/rotor in the housing
i wonder what the deal is with it ?
has anyone ever heard of this happening ?

 

also, there is metal restrictor plate thingy across the rear water port of the intake gasket for both heads,
they are closed off

is this supposed to be ?


thanks

 

That plate should be there but it should have a 1/8" or so hole in the middle of it. You may have the wrong intake gaskets.

 

FWIW the hole is there on each side to:

1. restrict the flow of heated coolant from head into the intake. i.e. you want the intake heated a certain amount (to prevent excessive cooling & icing from fuel evaporation)

and to

2. thermally stabilize the intake if the EGR is ON (which really gets the intake hot... so the coolant would actually cool the intake manifold). That's one reason why there is a water jacket that surrounds the EGR passages in a TBI intake.

If your gaskets lacked the tiny holes Shifty mentioned, then it would still run, but the intake manifold might be too cold, especially during startup, with the EGR not operating, and it might be too hot with the EGR on. The engine coolant would then enter the intake manifold at the front near the thermostat.