Pulled the heads off my '88 305 TPI auto today. My plan is to port the heads a little ( I have the SA kit, die grinder), have new springs & valves/ seals installed along with a 3 angle valve job. Apart from the usual carbon buildup, does everything look normal? There is one exhaust port in pic that has some crap stuck on the port wall that looks kind of metallic, though I can't see any damage anywhere else. How do I clean the crap off the pistons? or should I bother. I did try the water trick while I had it running to try to get the carbon deposits off, but I don't think it worked very well.

 

The one with the crap stuck in it.

 

Last one.

 

Looks good. Esp the heads. Looks like all were burning properly. Your going to want to drain the coolant when you put the heads back on esp when putting new headbolts in and torqing them. Good luck scraping all the old crap off the block. I hate that.

 

looks good. porting will clean all that crud out of those ex ports. i have cleaned pistons by bringing them to the top of the cylinder and very carefully hit them with a wire brush in a low rpm drill, while blowing the carbon off with a compressor. and really clean off all the old gasket crud, heads and block.

 

What casting number is that if you don't mind ???

 

081

 

I need to clean these heads off before I start porting. Can I just use engine degreaser? any other recommendations?

 

Should really dissasemble the heads and have them tanked and checked for cracks before you do anything else to them. If they check out good they will come back looking like new. Don't cost much at all.

 

yea, I was going to say to hot tank them, it's fairly cheap for what you get, they're clean as a whistle after that.

I just soaked a pair in my parts cleaner, and they came out a bit cleaner... good enough to port, then hot tank after...

wire brush on a drill on pistons should be ok, be gentle, that aluminum will disappear fast.

 

Ok, I'm almost done porting these things. I've noticed that most guys smooth out the edges of the square spark plug boss in the combustion chamber. Is this necessary, and is it to stop detonation ?

 

Interesting.... doesn't look like a stock TPI short block.

Dished pistons. They're supposed to be flat-tops.

Maybe it's been rebuilt? Too bad they hosed you like that.

 

necessary? no. reasoning, you are correct.

care to share some photos?

 

Hmm, maybe its just the angle but they looked like 4 Valve relief flat tops to me.

 

#8, with a little image enhancement....

Pretty definitely a dish.

I'd leave the crud on the pistons alone, cleaning them off is a waste of time, they'll be right back like they are again in a couple thousand miles.

 

Sofa, hasn't been rebuilt as far as I know, lady drove it for about 10 years before I got it and it only has 100,000 miles on it now. She also kept all the reciepts. What do you mean hosed?

 

IIRC the 305 TPI shortblock was the same as the LO3 shortblock. Here is a shot of my LO3 which has the same style pistons. I could be wrong though.

 

I was under the impression for some reason that it was supposed to have flat-tops. That's a HUGE difference in compression. But maybe I'm wrong.

https://www.thirdgen.org/techbb2/sho...hreadid=343951

 

Regarding cleaning the pistons...I used that carb/choke cleaner spray and was able to get most of the carbon off the pistons and they looked close to new. Just spray it on and wipe them.

 

Cleaned mine with a soft brass wire brush. It was a real pain in the butt. Still a good thing to do since they had a lot of carbon on them before.

 

The slight dish and 4 reliefs are what moved compression from 9.5:1 in '86 to 9.3:1 in '87.

Look like stock '88 "flat top" pistons to me.

 

Yeah, I see what you mean now. Couldnt really tell, either the computer is getting old or I am.

 

Here's what I took out of the heads (minus what's on my car and spread all over the garage walls). Sorry I got no pics of the heads yet. I was going to take some when I finished, but I had to get them to the machine shop before they closed. I'll get some when they get back. Thanks to F-Bird'88 for the tip on the Powerfist Die grinder. What an absolute deal for $68.00 CAD. from Princess Auto. It wasn't on their special anymore but they honored the price. Never skipped a beat, and my hands were never even buzzing after many hours at a time of grinding.

 

nice! I hope to get that much of a reward pile too

the best pic would be of the heads, so when you get them back all clean and pretty ...

 

Nice job, good look getting everything back in