bargain 400 build

Hey guys been a while, works been kicking my A$$ lately, broke open the "rebuilt" 400 i picked up for 450.00. Spins nice and smooth took the heads off to find new comtech head gaskets, heads are 6X-8's and appear in real good condition with a slight dry carbon build up on top of the pistons. walls are nice and smooth no ridges. And the best thing STD pistons, pulled the pan and this is what i found. Front main bearing is worst of the bunch, most look like new with no wear. Did not see any stampings on the backs of bearings, does that mean they are standards? rods have been number stamped, wondering if someone just did a bearing/rings re-build on it, lifters and cam look good and crank is smooth. will have to dig up specs and micrometer and start checking clearances. all in all looks like a good motor for the price. block is YS ?299009 with 491988 casting appears to be 71' 300 hp? date code is L201, he said it was a 71 block. Picked it up as a backup and possible stroker for the Tempest or a future 69' Firebird build. piston tops still have some carbon build-up in the reliefs, no pitting from detonation, looks like they were running it real rich. It will get treated to a .030 over bore, forged pistons and rods and hyd roller cam set-up in the long run (when i hit the Lotto...     ) All ready have a thumper wanna make this one a screamer.

can a nodular 455 crank be cut down to a stroker for the 400, as i have one thats beyond a .020 cleanup?

how do i clean out the infamous hidden oil passage and make sure its done correctly?

What would the compression be with 6x-8 heads (101cc?) or 6x-4 heads (96cc)?







 
http://s1098.photobucket.com/albums/g372/instg8ter/1966%20Tempest/

"learning as i go, and going as i learn"

Brian

You will have 8-8.5:1SCR with those heads.  
Horsepower sells engines and torque wins races

I would recheck that cam when you get it out. I guess your going to mic the crank so bearings aren't an issue. The acid from the exhaust that gets captured in the oil by blow-by. When you take an engine, and let it sit the crap in the oil will eat at some parts. Especially bearing material. Mating surfaces like cam and lifters. Thats because the oil drains off those parts.  In fact if you look at that cam I wouldn't make decision on it until I see the whole cam and lifters. Did you keep the lifters  in order? The bearings why they don't have any idenifacation is anyones guess. Possibly factory parts are still there. Most of it is replace as needed. Nice find. When you get to the heads really look at the valves and the cyl.head seats closely. Keep us informed OK? Good Luck.    
Thanks Bob  

motor was sitting on a stand for at least a year, bought it as a backup and eventual stroker build with Eddy heads. Don't have the money right now so if it specs out will probably clean it up put new cam, bearings, lifters and rings and keep it as a spare in case something happens to the 462.

Thanks P-man, guess i better start saving my pennys for the Aluminum heads, how many CC's can you take out of the 6X-4's with zero decking standard block and milling the heads comfortably?  
http://s1098.photobucket.com/albums/g372/instg8ter/1966%20Tempest/

"learning as i go, and going as i learn"

Brian

Gater, it's best to leave the X4's alone as well as the stock compression height with flat tops.,. Pontiac Engineers thought long and hard to come up with a great combo.,. unless you know something they overlooked, heed their design criteria as fact and true.
JMHO
 
When The Flag Drops,,,



The Bull Chit Stops,,,


P. Engineer, Engine Builder

I only mill and deck surfaces if they need it to be sure the surface is true and straight, never to raise CR.
I have had to 0 deck blocks because they needed it as they were decked before so the next decking brought them to 0, which also gives a better quench but never just to raise CR.  
Horsepower sells engines and torque wins races

Those 8 VR pistons give around 9.6:1SCR with a 72CC heads.  
Horsepower sells engines and torque wins races

Howdy g8ter, wondered how you was. I got an extra 400 I need to tear down and inspect now too. Still in the car though. Always good to have a backup, eh?  

hey ID, howya been bud....what kinda car is it in? Yeah good to have a spare, just in case. Eventually i would like to find a 69'-72' firebird shell to start work on, so i figure i can mix and match, would like to do stroked 400 with 5-6 speed manual in a TA clone resto mod.  
http://s1098.photobucket.com/albums/g372/instg8ter/1966%20Tempest/

"learning as i go, and going as i learn"

Brian

Workin hard kinda like you, man. Its a numbers matching '72 GP sans title, looks virgin. I'm gonna use the buckets and console off it, maybe the tilt. Your eventual plan sounds like a killer. Does your girl know how to drift the Tempest yet?  

Is there a lip at the top of the cylinders if not you may be able to hone and go back STD bore.
I would stick with the 400.  
Horsepower sells engines and torque wins races

no lip P-man just a little carbon buildup where the rings topped out but all bores are nice and smooth. If i run the stroker crank (461)the 6x-4's should get me right around 9.3:1 correct?

LOL ID, she has only taken it back and forth to the park with me a few times, has a new BF at school so she has not been home every weekend....did get to drive it through day after thanksgiving which is a miracle here in Michigan. Need to pull the 455 for a new rear seal, have to make a ceiling rack to store my hood so it does not get damaged or warped, figured i would get this motor broken down and to the machine shop to free up my heavy duty stand for the 455. Pontiac blocks are like land these days...."they ain't making anymore of it"  
http://s1098.photobucket.com/albums/g372/instg8ter/1966%20Tempest/

"learning as i go, and going as i learn"

Brian

Yes You will be right around 9.3:1SCR.

One thing to keep in mind is the more cubes the more they will need to be feed and I have seen many times were the larger cube Pontiac engine had a little problem making the 500HP mark were the smaller cube Pontiac engine did not this is due to the larger Pontiac engine not getting enough air and then it runs out of wind were the smaller cube Pontiac engine didn't.
If built the same the larger engine will put out its power at a lower RPM.  
Horsepower sells engines and torque wins races

really would love to get a set of eddy heads, but i looks like i may have to look for some 16's/48's/12's @ 72cc's if i stick with the 400 crank to get my compression where it needs to be correct? What recipe would you suggest if i go the 400 route to get me around 420 HP with a streetable cam.  
http://s1098.photobucket.com/albums/g372/instg8ter/1966%20Tempest/

"learning as i go, and going as i learn"

Brian

If you use the 8 VR flat top pistons then yes.  
Horsepower sells engines and torque wins races