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Discussion Starter · #1 · (Edited)
Well my Girlfriend has been needing her own car for a while now. So we got lucky and her father gave her they're old 1992 buick Roadmaster for "FREE"!! and they even put insurance on it for her!! I was like, "this is great now i don't have to get up at 5:00am every morning to drive her to work, because she has her own car now.
The car Has 300,000km's on it so I was planning or rebuilding it but I said what the heck, and told my G/F to go ahead and start driving it, for at least a week then I would have time to pull the motor and rebuild it.
Anyway she drove it for 2 days and on the second day it spun a bearing!!!!(the bearing that connects the connecting rod to the crank). I was in the car at the time and it happened at only 3000rpm's!!! A 350small block shouldn't throw rods at a rev ranges as low as that, so the motor was deffintally on its way out.
Anyway, I had it towed home and I decided that Im not going to sell it, but rather, Im going to fix it. I know that once you spin a bearing in the bottom end it, ruins the whole block and it can be rebuilt, but there is alot of Machine work involved. Which would be just too much $$$$$ for someone like me and make it not worth it, for the age of the car.
So I decided that Im going to pull the motor out of it. Then check the bottom end (which I know would be too much work to fix it, but the bottom-end has to come off anyway, so I might as well check it while I have it off).
I almost got the motor ready to be pulled I just have to remove the starter , flywheel and take the weight off of the engine so I can punch the Motor mount bolts out (had to grind the nuts off due to having no air compressor with an impact wrench). Then I just have to unplug the injectors, plug wires and everything else that needs to be unpluged.
I found a guy that owns a shop right across the road from me and he said that he would come over with his lift (which is on the back of his truck) and pull my engine for me for only $10, to save me the trouble/money of renting a cherry picker for $30+Tax and thats per day!! He will do this for me once its all ready to be pulled.
I flound a 305 Small Block out of a Iroc Z for only $300CDN. Once the motor is pulled out of my buick and the bottom-end is removed. Then I'm going to remove the botttom-end off of the 305sb and bolt it up to the top-end of my 350sb (I was told by alot of Chevy masters that they are the same block so it will bolt up with no modifications, the only difference is the displacement). so when I'm done I'll have a weird Chevy engine it will be a 350sb/305sb hybird and will probley be like a 5.1L-5.2L (which would in a way kind of make a rare motor, because chevy never made a 5.1 or 5.2L SB's... I dn't think anyway.
If there is any old Chevy Masters on MX-6.com, please PM me because this is my first chevy motor that I've ever worked on!

Thanks

Methman

PS: Just in case your wondering..I'm going to keep the top-end of the 305sb, and get another bottom end for it some day then put it in a old Malibu or a Trans AM ect. Then I'm going to Modify it to make a crazy rear wheel drive Mustle car. The other reason I wasnt to do this with the 305sb is because it has "tuned port injecton, which is from what I understand (and I don't know alot about GM motors) is a great feture for racing.

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Then I just have to unplug the injectors, plug wires and everything else that needs to be unpluged.
This part worries me. You say your going to a smaller displacement motor, you're going to have a problem with the fuel curves not matching, and in this case you will be way rich. If your an emissions state you will fail. Not to mention the engine won't run right. You may need the ECU for the MEMCAL for the IROC to make the engine run right. Also the term is "bastard" motor not rare. I will ask my resident GM guy when he gets back.
 
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A spun bearing usually just ruins the crank and the affected rod. If thats all that happened you could get away with putting the IROC crank in your engine, and replace that one rod, get a set of new bearings and keep the same displacement size to avoid any problems that Imagoon mentioned.

Now, if you actually "THREW" the rod, then your SOL. :)

Good luck, Chevy motors are easy.
 

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5.7 L ...."American Muscle"

This V-8 is a fine example of good old fashioned engineering.
I think that the best all around bet would be to attempt to rebuild the existing 350 if salvagable.
If gonzo, then consider another equivalent 350, either with low mileage or a refurbished one. They're relatively inexpensive and plentiful. Parts are easy to come by, to do whatever one desires.
At least you have an idea how the motor presently in it has been driven, while the IROC may have been hammered ! Something to think about. Flyswat made some good points about potential problems.
The 350 is stronger than the 305, but either would make a good motor for a streetable rod or muscle car.
 

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If you guys remember some of my earlier posts, I built my first small block when I was 17 (ten years ago). It was a 350 block with a 400cid small block crank, and the 350 5.7 inch rods. This requires custom pistons (which are really easy to come by for the small block chevy) and "relieving" the block so the increased stroke of the crank wont' hit the cylinder walls. Anyway-it creates a 383 cid engine that pulls like a raped-ape as it has tremendous low end torque. It dynoed just over 425 horse and 492 ft-lbs of torque!

First things first-placing the top end of the 350 on the 305 DOES NOT make a 5.1L! The bore and stroke remain the same, so the displacement remains the same. If the 350 heads fit (there are fitment issues due to the 350 having a 4 inch bore compared to the smaller bore of the 305; your cumbustion chambers are too big for the bore of the engine and leaves sharp edges that aid detonation) it increases air flow on a 305 based on the heads of the 350. i have owned 2 IROCs and rebuilt both. One I built a 4 bolt 350 with later style Vette heads (cause they were cheap) then upgraded the fuel system wiht a custom chip and 26lb/hour injectors; and the other i just rebuilt the 305 and ported the stock heads.

2nd-if you just spun a rod bearing you can easily (and cheaply) have the 350 crank turned down 10 thousandths and replace with the correct bearings. If it need replace the crank can be found here for $103: http://www.jegs.com/cgi-bin/ncommerce3/ProductDisplay?prrfnbr=1248&prmenbr=361 The cylinders will have to be honed at least 10 thousandths, more likely 20 or 30 over (just take the heads off and feel the groove the rings have left in the cylinder wall!) . But all rebuild kits compensate by providing larger pistons, rings, bearings, etc. Just pick up a Jegs or Summit catalog and have a look. Thier web sites don't offer much in the way of locating the kit you want, I just looked, but the mags have all you will ever need!

Small block Chevy rebuild kits are very cheap, and once completed, the motors run great. I suggest you talk to reputable shop in your area and rebuild the 350. Add a slightly better "RV" style cam, and use the TRW or equivelant forged pistons, and an oil pump. (Most "complete" kits will give you the pistons, rings, bearings, oil pump, gaskets, etc.) You won't regret the power and the experience.
-Britt-
 

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Discussion Starter · #6 ·
Well If I did indeed spun the bearing *ONLY*. Then I will put the crank from the 305 in the 350sb and get new bearings then be all set to have the 350sb run good again in her buick. But, of course, I won't know until I get her all apart.
If it turns out that the rod threw (which is possible, because the knocking was pretty loud and the car would die alot, then I just decided to just shut her down). Then Im going to put the 305sb bottom-end on the 350sb top-end.
As for the combustion chamber in the 350sb head being bigger than the cylinder boare of the 305sb, then Im going to try a few things....first is to see how much smaller the cylinder of the 305sb is than the 350sb combustion chamber, then I will try and overboare the 305sb cylinders as much as I can to make it match as close as possible to the size of the 350 head.
Or just install a 5th injector that the duty cycle can be adjusted on, and have it spray constanly, then just tune the duty cycle until I get a good muixture, or just put in a boost-a-pump- or somthing.

Thanks guys.

Methman

PS: Keep the replys comming.
 

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305 heads were always such a pain in the ass to replace spark plugs on. i used to have an old caprice with a 305. that thing felt like it would run forever. 260K+ on that thing and its still going!! as much as i love my mazda turbo power. i am still a chevy man at heart.
 

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If you place the 305 crank in the 350 it will reduce the displacement, creating a 330-something. If you go this route, you'll spend more than if you just rebuild the 350. As this is your first forray into the small block chevy world I strongly suggest you just rebuild the 350 (even if you have to find a suitable crank). The 305 from the iROC will be well worn, and a waste of your time, in my opinion.
 

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"350"

I full heartedly agree with Marolf. Keep the IROC 350 for your other project. Rebuild the 350 as a 350 ! You'll have far better results with less effort and expense. Do the right thing ! It'll be much simpler and rewarding in the long run.
 

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First you should know that motor was the largest available in any Gm four door. Later Roadmasters had a police interceptor motor that was rumored to be similiar to the Vette. When you pull down the lower end you will probably find no damage to the cylinder walls. It is posible to have the connecting rod resized if the damage to the crank was not too prolonged or extensive. If the cylinder lip is not too deep you may just cut it and hone the cylinders and go with oversized rings. It sounds like an easy rebuild with a replacement crank, bearings, rings and gaskets.

Why would you spend 300cdn on a used motor with few intechangable parts when you can add a few $ more and get a fresh 350 that will run stronger with no extra trouble?

I know Cadillac added more nickle to their large blocks. I don't know but buick may have spec'd additional alloying for a stronger block. You could have an engine worth setting back when the Roadmaster is retired.:)
 

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Discussion Starter · #11 ·
WOW! Thanks for all of the replys guys...I guess there is alot of people that started off building chevy small blocks, I talked the guy with the 305sb down to $220 and Im going to talk him down even lower when Im there with the Cash. I've decided that I won't buy it if I can get it for at the very most $175.
I still haven't got the engine out of the Buick yet (Its so damn cold here in Canada right now and I have no place but my driveway to do the work), but once I get the engine out I'm going to put it in my shead and use a keroseen heater to keep it warm in there. Then Im going to proceed to tear down the 350sb and see what the damage is. I think Im going to take your guys advice and just rebuild the 350sb (really though its not because of the fact that the 350sb/305sb hybird will run slower than the 350sb. Its my GF's car so I don't care about power. I'm going to rebuild the 350sb because I was told by a chevy master (member) that it would only last for 30,0000miles or km's {im not sure which one it is}, and I need a car that will last her longer than that), but I may still buy the Iroc 305 as a project motor to make an all out track racing Malibue or Motey Carlo, Camaro, Trans AM ect, basicly whichever car is lightest and is rear wheel drive, so I can get the most power out of the 305sb. Or Im going to rebuild the 305sb (after rebuilding the 350 to get my GF's car back on the road), and sell it so I can buy a running/good condition Iroc 305sb Camaro from a member on this board.

Thanks for all of the replys guys...I'll let you guys know when I have the motor torn down and what the damage is (I will also take pics) then get your guys advice on what to do from there.

Thanks

Methman
 

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Discussion Starter · #12 ·
UPDATE:

Found a Buick RoadMaster in the junkies with the engine still in it!!! and it wasn't seized, although I don't think it has any compression.
Anyway They want $200 for it, so Im going to buy it and check the bottom end out before it install it back on my GF's car, (to make sure the same thing will not happen again 3 days after putting the motor back together)

So IM going to do that. My GF has to go get a loan in order for us to buy this engine. Since they won't give loans for anything under $1000, Im trying to talk my girl into getting a $1500.00 loan, so I can take a $1000 of it and go buy my dream car (the 1st gen RX-7 with the origonal carburated rotory still in it and running good). Then take the other $500, and use $200 of it to buy the motor for the Buick. Then the other $300 will go towards parts that may need to be replaced in the bottom end of the engine I'm buying (as preventive maintance).
And here is what she said..."then I will have a $1500 loan I got to pay off, sorry but no" (I was going to pay the loan and not just the $1000 for the RX-7 but the other $500 for her buick). I was like OMG you need a car, and you know it!!!!! because im not getting up at 5:00am every morning to drive you to work, just to come back home and get an hours sleep. Then have to get up and go to work myself. I ws like you NEED A CAR and here is my dream car for cheap that can get you through the winter. Then by summer you can have your roadmaster back (because it will be fixed by then) and I'll take my RX-7 as a once-in-a-while driver. But my girl is so blind she just dosn't understand what my plan is so she is saying no and basicly taking away my DREAM CAR!!!!! and taking away my DREAM CAR IS not going to happen!!...so I told her she will have to PAY a mechanic to get her buick running again, because I'm not going to sit out there in the cold rebuilding an engine FOR HER (she will find that it will be alot more than a $1500 loan to pay a mechanic to do the job) or get up at 5:00am anymore. You may ask why I was such an A$$, well its like this... IM doing all of this crap for her to get her buick going again, I do alot of things for her and made alot of scrcrafices (sp) for her, and I will be Damned if Im going to do anything more for her if she not going to do the only thing I want...which is get my RX-7.

anyway thanks for listening to me rant, I just hope I don't get so pi$$ed off about her not getting my RX-7 that I get so mad at her that she leaves. I have an anger problem and when its somthing like this that is making me angry I get really angry...but I love her I just hate her (at the moment) for not helping me get my DREAM CAR!!!

Methman
 
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Heh, I feel your pain, but I'd avoid going into debt as much as possible. Its always better in the end. There will be another RX-7 someday, and you'll have the money :)

If you think having a girlfriend is bad, wait until you get married :lol:

Look at my sig to see what my wife is making me do :)
 

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Discussion Starter · #15 ·
UPDATE:

Well I calmly talked her into getting the loan for $1500 and she is going to get my RX-7!!!!! YES!!!YES!!!!YES!!!!!. I know loans are bad but I will be paying it, I may even sell the roadmaster after the winter for $3000 to pay off most, if not all, of the loan. then with the little bit left over We can go and buy her a small car that suits her good like a VW jetta, or a Toyta Corlla/Camary etc:

Well I'm hapy now IM getting my RX-7, I just can't wait until after the winter so I can start fixing the RX-7 up (engines fine, just needs a paint job and mabey a little rust work).

Im sorry to hear that your wife is making you part out your six!!!! Why don't you go and part out her Protega??? ;) })

Methman
 

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Discussion Starter · #16 ·
Well the guy Traded the RX-7 for a skidoo just before I got ahold of him to make a deal :mad: :rolleyes: , oh well :( . Now Im getting a $100 VW Golf that has a new exaust, new distrubitor and wires, very little rust (less than the RX-7 had). There is only one problem, the cluch is gone...it slips so bad that you can move the car at all, but I got in it and started it (it did and the idle was fine, a little rough at first but it hadent been started since the spring before last summer, so I assume thats why). So I'm going to give the guy the $100 (can't really go wrong could sell a couple of parts out of it and make my $100 back easy). He only lives like 10min or less down the road from me...so Im just going to get some chains and hook them to "tow hook" spot in the back of my MX-6 (well actually under it in the back but you guys get my point). (I wish the roadmaster was working Id much rather use that for this). Anyway then, after testing the brakes on the VW, Im going to hook the VW to my MX-6 with chains. Then get someone to steer (hopefully it won't be my girl friend) and I'm going to tow it home that way.
Then once its home I'm going to find a sopt in my driveway (if I can find one, that is.). Then jack her up and put her on blocks. Then just get her ready for a cluch job. Then I will order a Cluch kit for the car and while I'm waiting for the kit to arrive I will start removing the old cluch. One question.....is this going to be a hard job...I've never done a cluch job before, but this is a great way to learn.
I think I'm going to have to take the axle out on the side where the cluch pack is in order to get at the Cluch...correct?

Anyway, if there is someone with experience with changing cluches, on just cars in general Please PM me with a quick wright-up on how to do this, that would be nice....I'll also have a manual to help me...since I have to buy one for the TQ. specs anyway.

thanks

Methman
 
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