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1G Build/Maintenance recommendations for my 1G GSX

I21chardh

Probationary Member
20
11
Oct 10, 2022
Denver, Colorado
Recently bought my first DSM and I am fairly new to the platform and have been learning a lot as I go, from friends with DSMs, and from browsing through forums like this. I have some time off from work this month and now at the point where I can start working on this car.

I have a stage 3 built trans, t case, 4 bolt rear ready to swap, and all that is left is the engine. My plan is to pull motor for a full disassembly and inspection, rebuild. I will be replacing main and rod bearings, lifters, seals, springs/retainers, oil and water pump, belts, valves cleaned. What else should I consider doing while engine is apart as far as maintenance goes?

I was considering replacing stock crank for 4g64 crank as I have access to one in great condition for free. Regardless of crank choice, I want to upgrade stock rods to Eagle H beams and HKS pistons. Would also like to upgrade to 272 cams. I'm thinking I will need to upgrade to 1600 or 2150cc injectors along with any necessary supporting fuel mods.

The car currently runs well and is currently making 450+whp on E85/DSMlink at 23lbs on a gt35r with 1200cc injectors, GM MAF. I would like the car to be around 600. Does this plan seem to be on track to meet these goals? Thanks for the help! Excited to dive into this and learn a bunch in the process!
 
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wparks

10+ Year Contributor
85
46
Mar 19, 2012
Fort Collins, Colorado
Hey I21chardh - Must be a slow week with the holiday - surprised no one has chimed in. Welcome to the DSM club, I'm up in Fort Collins myself. NICE GSX man. Wish my paint looked that nice.

I'm a pretty much a noob but solid on the basics, just stayed closer to the stock track so I don't have much to contribute as to the road from 450 to 600. Thought I would start the ball rolling since I did have a couple of questions and comments. I'm glad to see you are doing your homework first.

Do you have a factory service manual? I see so much neglected or poorly done maintenance. I also see many upgrades that really don't make sense, are in the wrong order, or just done badly, and these are such beautiful and amazing machines that are disappearing quickly, so they are worth every bit of love we can give them.

You said it has a stock bottom end. Does it still have the balance shafts? That would be near the top of my list. I hate the smaller balance shaft belt both as ticking time bomb and as a matter of principle. I have never missed mine for sure, and a relatively easy mod while on the 'stand.

What about ARP main studs? Seems prudent for that power level. I like where your head is at on the Eagle rods and aftermarket pistons, though I have no up-to-date expertise as to brands/flavors. I LOVE mine.

Since you will have the crank out, sounds like you will have it checked/turned/polished for those new bearings. The rod journals on my crankshaft had been turned down slightly looser by the previous owner, and I was told that was a common racing trick but I don't know I would have chosen that path. Sounds like you will also have the block machined for those new pistons, are you going to over bore?

How long since the head was serviced? If it's been quite a while or wasn't done right by the last owner maybe consider decking the head, having the guides replaced, valves and seats reconditioned and vacuum fit tested? Not too expensive.

I love the Gates blue timing belt, and can't say enough about an OEM tensioner. I loved doing the timing belt on the engine stand, SO much easier! I got lucky and found a manual steering rack out of a lower trim model at the junk yard, and loved eliminating the gooey power steering pump, hoses, belt, and idler.

Anyway, prattled on long enough, and probably all obvious, but again, welcome to the club!
 
Last edited by a moderator:

I21chardh

Probationary Member
20
11
Oct 10, 2022
Denver, Colorado
Hey I21chardh - Must be a slow week with the holiday - surprised no one has chimed in. Welcome to the DSM club, I'm up in Fort Collins myself. NICE GSX man. Wish my paint looked that nice.
-Thanks for the response. Appreciate the help Ive received in very short time Ive been on here. Looking forward to diving into this and learning a bunch in the process.
I'm a pretty much a noob but solid on the basics, just stayed closer to the stock track so I don't have much to contribute as to the road from 450 to 600. Thought I would start the ball rolling since I did have a couple of questions and comments. I'm glad to see you are doing your homework first.
-Trying to my best to get as educated as possible on these cars! I have not been this excited about a project since I restored a Yamaha banshee a few years ago.
Do you have a factory service manual? I see so much neglected or poorly done maintenance. I also see many upgrades that really don't make sense, are in the wrong order, or just done badly, and these are such beautiful and amazing machines that are disappearing quickly, so they are worth every bit of love we can give them.
-I do have a downloaded PDF of the 1990 Technical Information Manual. I absolutely agree with all of this ^
You said it has a stock bottom end. Does it still have the balance shafts? That would be near the top of my list. I hate the smaller balance shaft belt both as ticking time bomb and as a matter of principle. I have never missed mine for sure, and a relatively easy mod while on the 'stand.
-It does have balance shafts still and I do plan on deleting.
What about ARP main studs? Seems prudent for that power level. I like where your head is at on the Eagle rods and aftermarket pistons, though I have no up-to-date expertise as to brands/flavors. I LOVE mine.
-Car already has ARP main studs. Im not set on which pistons yet but looking for around 9.5-10.1 ratio
Since you will have the crank out, sounds like you will have it checked/turned/polished for those new bearings. The rod journals on my crankshaft had been turned down slightly looser by the previous owner, and I was told that was a common racing trick but I don't know I would have chosen that path. Sounds like you will also have the block machined for those new pistons, are you going to over bore?
-The new crank I would put in is already ready to go. I would stay standard bore at 85.00 unless i need to go up then will need to get block machined.
How long since the head was serviced? If it's been quite a while or wasn't done right by the last owner maybe consider decking the head, having the guides replaced, valves and seats reconditioned and vacuum fit tested? Not too expensive.
-I have only been in contact with the original owner and not the owner who had the car before me, so Im going to just inspect and service everything for peace of mind including guides and seals. I have access to some evo springs and retainers I may use when rebuilding.
I love the Gates blue timing belt, and can't say enough about an OEM tensioner. I loved doing the timing belt on the engine stand, SO much easier! I got lucky and found a manual steering rack out of a lower trim model at the junk yard, and loved eliminating the gooey power steering pump, hoses, belt, and idler.
Timing Belt looks like it was replaced at some point and is still in good condition but again I will probably just do a full timing job and have peace of mind
Anyway, prattled on long enough, and probably all obvious, but again, welcome to the club! :thumb:
 

wparks

10+ Year Contributor
85
46
Mar 19, 2012
Fort Collins, Colorado
Sounds like you are in great shape, know what you are doing, having a lot of fun and on a great path. It's hard to provide feedback to someone who knows what they are doing as I'll probably just repeat what you already know, and I apologize if that's the case, but in an effort to be helpful it's worth saying anyway.


Were you going to have the block inspected by the machinist? If you are going to do it yourself, I wanted to mention I picked up a set of telescoping bore gauges from Harbor Freight and used them with a micrometer to check the roundness and wear in the cylinders. I have found there is little reason for re-boring unless they are badly out of round. I make it a point to at least cross-hatch hone the cylinders to help the new rings seat, and you will want to check the gap on the new rings in the cylinder and adjust fit if/as needed. If that's done it's hard to see what more benefit boring provides. However, in the rarefied air of 600HP class maybe I'm smoking crack and the gurus would have a different opinion?


I have been told that unless it has been done once somewhere mid-life it's always a good idea to have the head decked on these large aluminum heads as they tend to warp over time. Maybe with APR head studs and MLS it does not matter so much. If it has been done you will see the thickness of metal taken off by the machinist stamped somewhere on the edge of the surface. I picked up a billet bolt-on valve spring compressor tool- made life SO easy.


You mentioned you have the "1990 Technical Information Manual"- like this one?:

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If so, that is a great manual with lots of detailed "how it works" information, but it's not the factory service manual- it does not have all of the debug, service and repair procedures. You will want volume 1 (engine, chassis and body) and volume 2 (electrical), and the actual silver/blue Mitsubishi version is by far the best. Since you seem to have the funds, I would suggest this excellent set on ebay for $136:


Or there are sometimes cheaper ones in bad condition. Personally I love having a paper book- You can have it right on the engine with you as you are debugging, especially electrical. Nothing beats the factory service manual for everything you need to know.


Yes, good- a full timing belt job is a must. I have seen the main belt replaced and the inner balance shaft belt be completely neglected, waiting to break and trip up the main belt. It felt so good being able to remove that belt and tensioner. The hardest part was removing the cam-style bearing for the balance shaft and re-installing it turned to block the oil port. They make a special tool to do that, but I just used a long punch, small hammer and a lot of patience. I'm sure you have heard to pick up an aluminum or plastic cam gear lock (makes it so easy), a timing belt tension relief tool (I made one out of all-thread), a 2-pin tensioner pulley insert adapter, and a bolt-on locking bar to hold the crankshaft gear while you remove and re-torque the center bolt. (I made one from a 3/16" flat bar) As you can probably tell I enjoy staying under budget :D
 

enriquez2000

Proven Member
1,793
263
Oct 5, 2014
fort collins, Colorado
]




The hardest part was removing the cam-style bearing for the balance shaft and re-installing it turned to block the oil port. They make a special tool to do that, but I just used a long punch, small hammer and a lot of patience.
To remove balance shaft bearings i used...well... the balance shafts.. LOL

Youre in FOCO @wparks ? Me too! What part? I could use a local dsm buddy!
 
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