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Thinking of buying a spare. motor to build



GTP rods are stronger than NA rods, gtp crank is better as well, we used gtp bottom end and put diamond racing dished pistons with a t66 up top on my buddies impala.

the gtp rods are stronger for sure, it was an NA block.

Also for reference we had done a quick fun run and my Z28 was a mid 11 second 1/4 daily driver and the impala put buss lengths on me and he had subs/box/tools/full interior... Since the car never ran at the track our best estimate is it was at least a mid 10 second car.
 
ls1adam84 said:
GTP rods are stronger than NA rods, gtp crank is better as well, we used gtp bottom end and put diamond racing dished pistons with a t66 up top on my buddies impala.

the gtp rods are stronger for sure, it was an NA block.

Also for reference we had done a quick fun run and my Z28 was a mid 11 second 1/4 daily driver and the impala put buss lengths on me and he had subs/box/tools/full interior... Since the car never ran at the track our best estimate is it was at least a mid 10 second car.
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GTP crank is the exact same crank as the NA crank. Rods are made of same materials.
 
ADecker said:
I have heads and and ST5 in my basement, along with a double roller. Head studs on the way then the 600+ wHP fun begins.
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Scottydoggs said:
JUST NO! like said earlier, dont touch the bottom end. or you'll just waste it. thats called a 200 mile engine.

your also gonna want a way to tune it when done. it should run on a gtp stock pcm, but a tune will help it out.
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Question: What the hell? Why do people have issues building a short block? I don't understand. I have built everything from Briggs and Stratton and other small engines, 2 cylinder 2 stroke Rotax, Lycoming I/O 360, LS1's, several Chevy 350/383'sQuad 4, Ford 3.8 SC, 3.1/3.4's and never had any issues with an engine coming apart. Not to say everything has gone perfectly, but come on a 3.8 Buick? What's the deal? Not trying to be a smart ass or anything just seems really odd that messing with a bottom end would be a 200 mile engine unless you do like my dad did on a VW engine and torqued the mains and rods without using a torque wrench and seized the engine after about 5 miles that was in the early 70's when he was becoming an aircraft mechanic in the Army and thought it's just a car engine it doesn't need to be held to the standards that aircraft do.

Jeff
 


J57ltr said:
Question: What the hell? Why do people have issues building a short block? I don't understand. I have built everything from Briggs and Stratton and other small engines, 2 cylinder 2 stroke Rotax, Lycoming I/O 360, LS1's, several Chevy 350/383'sQuad 4, Ford 3.8 SC, 3.1/3.4's and never had any issues with an engine coming apart. Not to say everything has gone perfectly, but come on a 3.8 Buick? What's the deal? Not trying to be a smart ass or anything just seems really odd that messing with a bottom end would be a 200 mile engine unless you do like my dad did on a VW engine and torqued the mains and rods without using a torque wrench and seized the engine after about 5 miles that was in the early 70's when he was becoming an aircraft mechanic in the Army and thought it's just a car engine it doesn't need to be held to the standards that aircraft do.

Jeff
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Because on these motors, once you take the main caps off and pull the crank the block twists. You need to line bore the block to be sure it is straight before you reassemble everything or it won't last. I'm sure there are some other things that need to be done but this one is for sure. Can't be done like your average smallblock chevy.
 
The way things wear and warp in these engines makes it really hard without the correct (expensive) tools and (expensive) machine work to make it worth it. Here is the real question:

If ZZP made an 8 sec pass on a stock bottom end, and no one on here is even remotely close to having a (single engine) turbo setup near capable of an 8 sec (800+HP) pass, why bother building the motor. You wont hit the limits, why raise them?
 
J57ltr said:
Question: What the hell? Why do people have issues building a short block? I don't understand. I have built everything from Briggs and Stratton and other small engines, 2 cylinder 2 stroke Rotax, Lycoming I/O 360, LS1's, several Chevy 350/383'sQuad 4, Ford 3.8 SC, 3.1/3.4's and never had any issues with an engine coming apart. Not to say everything has gone perfectly, but come on a 3.8 Buick? What's the deal? Not trying to be a smart ass or anything just seems really odd that messing with a bottom end would be a 200 mile engine unless you do like my dad did on a VW engine and torqued the mains and rods without using a torque wrench and seized the engine after about 5 miles that was in the early 70's when he was becoming an aircraft mechanic in the Army and thought it's just a car engine it doesn't need to be held to the standards that aircraft do.

Jeff
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give it a shot, let us all know how long it lasts. lol its the only block under the sun you've not re built too.

one guy popped in here, him and his dad were doing a rebuild, we told him not to. his dad said they dont know jack lol and they rebuilt it and we never heard back from him, ( thinking cause it blew up soon after) and we told ya so lol
 
I have built a lot of different engines, and they have been complete rebuilds, other than the Lycoming (aviation machine shop) most went to the machine shop and everything has a micrometer put on it afterwards. I also have more tools than the average guy would have. I mean if your rebuilding with nothing more than plasti-gages, a socket set and a torque wrench you don't have the proper tools for building the engine anyway. Sure a lot of people get by with less but I just chalk that up to EFS. Who in their right mind would rebuild an engine, especially a high performance engine without having everything properly checked and machined? I'm not in need of a new motor, mine is in good shape so far, and if I were I'd end up pulling a JY motor and take it down mark it up and take it to the shop have the work done get the parts back and check them. That's if I wanted something different from stock like changing compression ratio or something major, other than that I would probably just drop in a low mileage JY motor. This isn't the 60's anymore where a 60k engine was on its last legs.

Edit: now on the flip side of that coin if you were told you shouldn't rebuild an engine because it'll blow up and you rebuild it and it works fine and you don't have any problems would you come back to this forum?

I would like to know more about this 8 sec pass on a stock shortblock. While anything is possible, these guys ran a cast crank, hypereutectic piston engine and made 800+hp? For how long?

Jeff
 
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The most recent part out here was from a blown motor after a full rebuild.... He thought the same thing - took it in had it balanced and everything. Scary
 


What's a "blown motor" is that thr same as "it's broke, it don't work". Come on guys there is no technical discussion on these issues it sounds like a bunch of kids that hear something from one or two sources and take it as gospel. I'm interested in root cause analysis not conjecture. This is the technical discussion area correct?

if I remember my 3.8L history correctly the Ford 3.8L is a copy of the Buick 3.8 with a few changes. So you mean to tell me that Ford can make a better copy than GM can make original?

Jeff
 
There's a few guys that rebuilt them with success but way more that ended up with a 200 mile motor and a hole in their pocket. Casper rebuilt one not to long ago and last I heard still good to go. The main point I thick most of us share is after what's 2k in machine work at the end of the day one could easily pick up a motor for $300-500.. Replace a few gasket and have a motor that probably outlast the car.


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Thank you Redcompg, that's a much better answer. But I would still like to know what failure modes they have seen. So what makes this any different from the 3.8 Buick engine used in the grand national and regal T type?

regarding the Ford 3.8, yes the head gasket monster is alive and well on those engines, though my 95 Taurus has 175k and been a great engine. My Tbird was a PITA, but running 13psi bone stock with a restrictive exhaust isn't helping along with Aluminum heads and most people's lack of being able to properly bleed the cooling system. We used copper then Comitec (sp) head gaskets and they are much better than the originals. Currently there are several under 10 second cars on the forum and at least 14 that are 12 or under. It's not a bad engine if you know what you are doing. Aluminum headed, sequential fuel injected supercharged AND intercooled from the factory in 1989 no less.
 
The main reason these engines fail during rebuild is people neglect the fact that if you take out the crank, you have to have the block checked for proper straightness on the crank journals due to the design of the crank main caps. Over a period of heating and cooling cycles, the block wants to "warp" and the only thing keeping it from doing that is those caps. You can put rod bearings in all day long as long as you pay attention to the production date on the block (you can't put rod bearings in a 95 block...the thickness is wrong...I've measured this on multiple early block 3800.) If you have a block dated year 97 and up, you can put rod bearings in as long as you measure properly...and I'm not just talking plastigage...the rod journals and the big end of the rod must be measured as well. Good luck with your rebuild.
 


Sven,

That at makes more sense. Basically it boils down to improper attention to detail. I'm not new to engine building so I do understand proper procedures. I just think that in the technical forum should have higher standards. Discussion from knowledgeable people about the subject in question. You have a guy that wants to know manifold air temp which I think is a valid question and I would think that as long as these cars have been out you guys would have all kinds of data. There isn't, he basically gets laughed off the board. When you are trying to get the most out of any engine you need to know everything going on. Guessing is grenading is what I like to say.

I'm not planning a rebuild. If got to figure out why it's not running right first. (Suspected Knock sensor)

Jeff
 
Sven The Baldman said:
GTP crank is the exact same crank as the NA crank. Rods are made of same materials.
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Sorry I realized I did not specify, we used the crank and rods from a gen 3 gtp. Although I think there were some differences between 2004 to 2005. I apologize for that I guess that's what I get for sitting here at work with 4 tasks to do and trying to read stuff here, I am getting too old for this multi tasking crap.
 
ls1adam84 said:
Sorry I realized I did not specify, we used the crank and rods from a gen 3 gtp. Although I think there were some differences between 2004 to 2005. I apologize for that I guess that's what I get for sitting here at work with 4 tasks to do and trying to read stuff here, I am getting too old for this multi tasking crap.
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Yeah, that was the series 2/series 3 changeover. However the only thing different still was the rods...they went from cast to powdered metal. Cranks remained the same for gen 2 and 3 though.
 
ZZP and stattama made the 8 sec stock block car. Stattama.com has pictures and build info. intense s4 heads, stattama turbo cam, stock l67 bottom end.
 
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