Gen 6, 454 Rebuild(long)

Spareparts

Member
Dropped my Block off at the machine shop about two weeks ago. Called today to check up on it and was told they have not gotten to it yet.
Not a problem though. When i dropped it off they told me it would take about a month give or take.
 

Spareparts

Member
Yup it does. Have other things to do though. Last weekend i changed all my under hood AC stuff and ordered a AC service kit. Vacuum pump and gauges.
This weekend ill be getting that filled just in time for the summer to finally start around here.
 

Spareparts

Member
So i was thinking.
I had no real goal for this engine when i joined looking for advice except for buying parts that would work well together and come out better than stock
So with that in mind i think it will be easier to have a goal that is reasonable and attainable and work towards that.

Stock the 1998 Vortec 454 engine is listed to have,
290 HP @4000 rpm
410 LB-Ft torque @3200 rpm.
9.0:1 compression ratio i think.

I'm thinking 89 octane, 350/400 HP and 500 LB-Ft torque in the 1200-5500 rpm range, Smooth idle
Seems like it would be easy to get to with the proper parts?.
I do plane on dumping the FI and installing a Edelbrock Duel plane intake and rebuilt 750CFM quadrajet. I do know how to read plugs and tune carbs.
I can't find any long tube headers for my application so stock exhaust with dual exhaust will need to be good enough.

Do you think this is a realistic goal?
 

Grumpy

The Grumpy Grease Monkey mechanical engineer.
Staff member
the goals rather easy to reach, I don't know why you would dump the EFI if its working correctly,
as its usually going to provide lower emissions smoother running and better fuel economy,
but either induction will work fine
Id try to boost the compression marginally to about 9.6:1 and maybe upgrade the cam.
as previously discussed
long tube headers and a low restriction exhaust certainly won't hurt
are you installing the BBC in the suburban, Ill look for headers

verify these fit before you order
 

Spareparts

Member
Yup, going in the suburban.
The reason im dropping the EFI is i can not tune it my self and im not paying someone $300 and make an appointment to do it every time i upgrade something.
In the future i will be adding a sniper system but for now the main concern is getting it together and in the truck and a carb will do that just fine.
I have found that in the past that in a few weeks maybe a month i can get a good carb tuned in pretty dang good rivaling EFI. the only real place a carb is lacking is cold startup and drive ability for the first 5ish or so minutes and i was always taught to let a cold engine warm up a little before driving it anyway.

PS. They do not fit a 1998 K2500 suburban. Thanks for trying!
 

Grumpy

The Grumpy Grease Monkey mechanical engineer.
Staff member
if your more comfortable with a carb, then by all means go that route
 

Spareparts

Member
Yeah, i do love carbs but i also love remote start when it's 5am, 20 degrees out and i need to get to work.
Always liked a well tuned quadrajet. Decent mileage around town and that awesome sound when you're holding it to the floor:nodding:
 

Spareparts

Member
So im researching parts this morning and lifters came to mind and as usual there are several choices available. Ill stick to 3.
Choice 1
Choice 2
So then i find this Choice 3 from Milling.
Now we all know OEM is usually the way to go for a lot of things but sometimes aftermarket is as good or better and Milling is or was a good reputable company.
Saving a few hundred dollars on lifters would be sweet but what's your opinion on this lifter subject?
 

Grumpy

The Grumpy Grease Monkey mechanical engineer.
Staff member
ID talk to the ISKY or CROWER guys, about your build and the applications needs ,in their tech dept's
,all the lifters you linked to use a spider retainer,
and that's very well proven to be a weak point once the lift and rpms loads significantly increase over the stock cams design limits.
linked aftermarket lifters have a better proven durability under higher stress, better lubrication and in some case better materials and closer tolerances


Id ask about the version for your particular application


why use stock lifters when there are lots of much better quality hydraulic retro-fit lifters with significantly better potential rpm capability for not much more money? even if you were going to pay $200-$300 more for the linked hydraulic roller lifters, they have a significant advantage in that they don,t tend to have issues with the lifter retention spider or dog bones failing
bentspiderspring1a.jpg



bentspiderspring.jpg

the aftermarket linked lifters have advantages at times to handle valve lifts exceeding about .500 and rpm levels exceeding about 5800 rpm much better and with fewer issues than the G.M. stock design
 
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Spareparts

Member
Well it struck me i could just measure mine provided I'm measuring from the proper spot.
Center of piston pin to top of piston measures 1.625.
 

Grumpy

The Grumpy Grease Monkey mechanical engineer.
Staff member

might help
 

Spareparts

Member
So here is an update. Picked it up last Thursday before just before they closed and have spent the weekend checking it out.
I did not end up with what i wanted. Through miss communication both ways (machine shop & me) Parts being out of stock i pretty much have a stock short block that appears good. Bored .030, 10/10 crank, cast flat top pistons with 2 valve reliefs, moly rings.
I should probably check all bolt torque.
Pistons are .035 below deck @TDC

Refreshed heads that are assembled wrong that i can fix. 6valve springs are installed upside down. This is from a supposedly reputable machine shop. Heads were surfaced .005, I believe 100CC for Vortec heads from what i have read.
I'm looking at this cam.
Cam # 12552296 measured
@ 0.050
ID 206
ED 211
LSA 118
ICL 115.5

IVO -12.5 BTDC (- indicates ATDC)
IVC 38.5 ABDC
EVO 46 BBDC
EVC -15 ATDC (- indicates BTDC)
ECL 120.5
Overlap -27.5

From what i can tell using the DCR Calc i'll be close to
DCR of 8.06
SCR of 8.73
CP of 193.29psi
Does this look close to correct?
I do plan on cleaning up the oil return ports on the head's. Since i have to mess with them, i might as well improve them what i can.
Funny how a guy starts with big plans and ends up just happy to get something usable.
 

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Grumpy

The Grumpy Grease Monkey mechanical engineer.
Staff member
"
Funny how a guy starts with big plans and ends up just happy to get something usable."

unfortunately thats all to frequently the case!



and yeah its critical you get a knowledgeable and skilled machinist that has a decent attitude ,
who gives a crap about providing quality work.
if your dealing with any unskilled, or uncaring "machinist" who has a doesn't give a crap, attitude,
or some clown who is only concerned with making money, and pushing parts out quickly,
as fast as he can, your partly screwed going into any project.
a good machinist will point out your options, and suggest you use quality parts, and suggest potential upgrades,
he will ask what you intend to accomplish,
 
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Spareparts

Member
YES IT IS!
I suspect it was the shop lackey that put my heads together. Guy in his early 20's probably learning, so i guess i can kinda understand that, But.
The mentor should have checked his work and no excuse not to.
I checked the torque on the rods and mains. According to my torque wrench they are right on.
Thing is the shop has been there for a long time and does have good word of mouth reviews.
Anyway i will be talking to them tomorrow about the heads being assembled wrong. Don't know what to expect from them but atm i just happy to have it back.
 

Grumpy

The Grumpy Grease Monkey mechanical engineer.
Staff member
my BROTHER-IN-LAW got a short block back from a machine-shop, he paid to have rebuilt,
I used rarely in florida, as IM now in texas, it already had the oil pan installed on it so I had a short/mild argument asking him to remove the pan to verify the torque wrench loads on the rods and mains as it would require he buy and install a new gasket... we were very glad he did take the time and effort to check, with my prodding him relentlessly,
as one connecting rod cap had connecting rods nuts finger tight at best:facepalm:
 

Spareparts

Member
Here is a question for ya.
I was talking to a guy and he was saying that the gen vi 454 uses different size main bearings. I figured he was saying they are different from gen IV, V. Ok could be true i don't know for sure.
NO he was saying there is a difference in size between #1 and #5 on a gen VI. and the bearing manufactures do not use the proper size bearing's in a main bearing kit and the only ones that fit properly are GM performance bearing kit.
Sounds like BS to me but maybe not?
Also, through reading im wondering if it is a good idea to soften the combustion chamber sharp edges a little?
 

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