time for another good idea vs. bad idea...

[91blackeye]

alright, lemme start off by saying i have no pix right now. will have them by tuesday the latest..

i have been on a scavenger hunt to find my requirements for a new supra... and i think i have found it.. maybe..

i know, from experience, and being told a million times that these are not good cars to own if you are on a budget, but... i can't effing resist.

and im not on a super tight one anyway...

i found an 89 turbo, 5 spd, black exterior on super super dark maroon interior, in IM-EFFING-MACUTLATE condition. no dents anywhere, to messed up paint, aside from slight oxidization on the targa, new weatherstripping, the interior is amazing!! no rips tears... nada, not even on the dash. the odometer is read 126305 original miles... the guy is asking 1k.

i know right? why dont i own it right now?


BHG.

i need to know if there is anyone here who could possible help me find out if the block should be resurfaced, or if i could get away with not doing it, and just having the head resurfaced, and at the same time have some pocket porting to rush more air to that turbo...

if the block needs to be done as well, i couldnt afford the car...

the guy has done all the expensive parts of the rebuild i.e pistons, bearings yada yada. he has the head gasket, all the parts ae there, he already has done k/n intake, and FULL 3 inch exhaust, hks bov...

so, any adivce SM??

i love you all lol.

 

[R1GG5]

buy it, a clean chassis with motor problems is easier to fix than a good motor with bad chassis. I would be all over it, block needing work or not.

 

[91blackeye]

buy it, a clean chassis with motor problems is easier to fix than a good motor with bad chassis. I would be all over it, block needing work or not.

lawlz, that is what i have been noticing on my quest to find another car...

i will look at the car again to nad some pix, post up here, see what you guys think..screw my trip to s.f....ima go get the pix tomorrow...

 

[91blackeye]

i did some searching, and i didn;t find exactly what i was looking for... and this is going to embarrase me to even ask this question, but i figured why not lose some self respect if it saves me thousands fo dollars and the biggest headache i could possibly imagine right now...


so...


how do i know if the block has to be resurfaced after bhg? does it ALWAYS need to be done?

if not, what about the head? does ti always need to be resurfaced after bhg?

and what if i resurface one and not the other? to my current understanding, it wouldnt matter as long as i kept the factory distance between the two as to maintain stock compression and whatnot...


help?? please??

 

[tacoma_kyle]

I suppose the only real way to check for flatness is having the proper tools...machine shops will have.

I would expect you can call a shop and ask if they can check for flatness and recommend machining or not. I doubt there is a easy way to do it at home when you're measuring thousands of a inch.

That is unless there is obvious corrosion or pitting on any part of the surface that will catch a finger nail...


There is no reason why it should ALWAYS be done on any engine rebuilt. All it does is give you a knew known flat surface. It could very well be fine. Yeah could change compression if you desire... I think in a lot of cases it is simply reassurance that when you assemble the and drive it, you don't have issues 200 miles later.

I -think- most frequently heads are done. Blocks often too, but heads are generally more prone to mis-shaping than blocks.

 

[Flateric]

The biggest easiest thing to check for without being totally experienced is galvanic corrosion. If the water ways have tons of holes and pits then it's a sure thing that you have a BHG that has gone too far and I wouldn't risk even using the head even if it were machined. You never know how deep they can be or how much weaker they have made the head.

 

[USPturbo89]

if you have the money yea get the head resurfaced.... thats my opinion. but just be cautious....

 

[I.M.Tech]

this may be what you are looking for, I do head jobs all the time, even on aluminum blocks. If you take a metal ruler and lay it on its side, you can take a micrometer ( about $30 at your local auto parts store) and gauge the distance at the cylinder walls on the block. if they all mic out the same, you can take a 3m scotchbrite abrasive pad and clean the surface of the head without machining the block. you will know the 3m scotchbrite abrasive pad because it is green, and has stiff rubber bristles on it ( they come in 2" or 3". buy the 2" pad), made to screw on to an angle grinder. normally auto body supply stores carry them. clean the head surface on the block. then take the head in to hot tank at the machine shop. be careful using the 3m abrasive to not sit in one spot too long though.

 

[91blackeye]

oh make no mistake, i plan on doing the head either way.... i fgured why not you know? and it would give me good exuse to port 'n polish it as well...


im just really iffy about the block... i mean, visually, it looks great actually, very clean...i just dont wana buy the car then realize i pretty much would be better off with a different 7m.

and 7m it will stay by the way... ^_^

thanks for the info thus far guys!! super helpful!

 

[91blackeye]

this may be what you are looking for, I do head jobs all the time, even on aluminum blocks. If you take a metal ruler and lay it on its side, you can take a micrometer ( about $30 at your local auto parts store) and gauge the distance at the cylinder walls on the block. if they all mic out the same, you can take a 3m scotchbrite abrasive pad and clean the surface of the head without machining the block. you will know the 3m scotchbrite abrasive pad because it is green, and has stiff rubber bristles on it ( they come in 2" or 3". buy the 2" pad), made to screw on to an angle grinder. normally auto body supply stores carry them. clean the head surface on the block. then take the head in to hot tank at the machine shop. be careful using the 3m abrasive to not sit in one spot too long though.

in regards to the micrometer, and me checking the cylinder walls, are they all supposed to be exactly the same, or is there a bit of play that is allowed normally?

 

[HommerSimpson]

A strait edge from snap-on is like 86 bucks... its a 2inch by 36 inch x 1/4 think bar of steel thats perfectly flat on one side... and a feeler gauge is a few bucks....

its not hard to do

 

[HommerSimpson]

A strait edge from snap-on is like 86 bucks... its a 2inch by 36 inch x 1/4 think bar of steel thats perfectly flat on one side... and a feeler gauge is a few bucks....

its not hard to do

also... i have only messed with 2 -7mgte blocks.... both warped on #6 cyl you can visibly see it if you look hard enough... the very back of the block were the cly and block meet...personly i think its from the egr valve passage heating up the block more there

 

[ForcedTorque]

Simple answer..........What head gasket are you using? If it is metal, you need to do the block or it will fail. I've seen intake, exhaust, port/polish so far. If you plan on going further with it, you will want to start thinking about metal.

 

[91blackeye]

the current owner whom i will be buying the car from has an oem gasket, so it goes squish lol. im not that dumb... i know if i use mhg i need to do the block... as far as power goes, im only looking for 320-350 whp....


silly huh?

 

[Stretch]

As long as there are no cuts or nicks in the block surface you can get your fingernail stuck on then you'll be fine for a stock-type headgasket. If you want metal, may I suggest Cometic; they have a required RA value of 50 or less I believe which will provide the best allowance for any micro defects in the mating surfaces. For 300-350hp stock would be fine. If you do want to go with metal hg, just surface the block too. Do it now, or do it later you choice. You will be doing it eventually though

I vote just get a stock toyota hg and slap it back together well, and enjoy the car. Buy it first though.
eric

 

[91blackeye]

i kinda have been thinking about the block thing... it would be done sooner or later either way...so.. mebbe just do it now?

im gunna snatch some pix of this car in the daylight...maybe it doesn't look as great as it did last night lol...

im gunna toss the pix up later this afternoon guys.

 

[Doward]

Um, everything I've heard it so NOT hot-tank anything aluminum - it'll destroy it!

 

[91blackeye]

Um, everything I've heard it so NOT hot-tank anything aluminum - it'll destroy it!

the 7m has an allum. head??

i thought the whole thing was cast iron???

 

[Keros]

A grand for a clean chassis? Even if I wasn't looking for another or new supra, I would have paid cash, on the spot, and waited for AMA to tow it home.

Motors are a bazillion times easier to fix than paint and rust.

 

[91blackeye]

A grand for a clean chassis? Even if I wasn't looking for another or new supra, I would have paid cash, on the spot, and waited for AMA to tow it home.

Motors are a bazillion times easier to fix than paint and rust.

well...im very inexperienced with both...so.. motors, especially ones that aren't a SBC are very intimidating for me...