Engine Rebuild / Recipe

[TurboManiacal]

Hey All,

Gonna try to help Bezerk (Rene) out with his engine woes. He'd really like an engine w/ warranty but location / price is prohibitive in this case.

I remember Myclone did an excellent write up several months ago on what his dream builds would be in

• Low Budget
• Medium Budget
• All out Build

I tried the search but it's down at the moment.

Here's what we're up against and have to work with:

• 1 Block that had no compression in one piston but maybe bored out to the max (.060 over already)
• 1 Block that spun the crank and may not be a viable rebuild candidate.
• My old block. This engine blew a head gasket and was driven 25 miles. Compression was 50psi in Cyl #1 and was knocking real good when it was parked for my Kosovo trip. When I pulled it out I checked the #1 spark plug and the tip was destroyed. Lots of metal shavings in the oil. I'm thinking this is our most viable rebuild candidate.

Screening criteria:

It's been expressed that we should keep the cost down under $1500 for parts.

The beauty of the situation is Rene owns his own Machine shop. We will need all the specs and machining instructions.

I'm hoping for a step by step comprehensive listing of things that need to be considered when building up an engine.

Maybe with the proper inputs...this could be a vault posting.

 

[Sy769]

Block selection:

#Check the bores for wear and size. I highly recommend a sonic check.
Core shift does occur and you could have inadequate wall thickness.
.040 overbore is about the max although .060 is possible but I would use water jacket filler to reinforce the lower part of the cylinders.

Non Syty blocks should have four bolt mains installed and then be align bored.
Head gasket surfaces should be machined if possible.

#Rods- L35 are better than stock although for a few $$ Eagles are much better. The next step up is probably Olivers.

#Crank In most cases a quality prepped stock crank will work. Consider nitriding or cryo for more strength.

#Pistons. JE/SRP and TRW are good choices for the money. Not really an area I would skimp on as our motors are so detonation prone.

#Oil pump- use a Z28 type Melling oil pump

# Timing Chain. Use a double roller Cloyes or similiar,

This will get this discussion good and started.

 

[bezerk]

First i have to say: thanks for everybody who is helping.

maybe if somebody knows something of the numbers that are stamped onto the pistons of my stock block? he could tell me if this already is an overbore?
ofcourse i should measure it up, but where did i leave that thing
It would be great if i can overbore my engine (not the one with the crankshaft damage).
So i could do a overbore before Ryan (Sigo) comes to bring his engine, So the next time he is coming to vistit we can do the job together.

My stamped number are: on the inside of the piston on the round wall (not the bottom) is crircel with a "7" inside and "GM" under it.
next to that "8269."square with an "E" in it.
next to that "1K"
next to that square with "1409" underneed "7270"
next to that circle with a "Z" in it
next to that a square with "-0" in it

about the cost of the parts.
would like to use Eagle H-beams, clevette bearings, JE-pistons.
please give me options on the camshaft, aswell as crankshaft
what rollerlifters should i use?
wich rockers??

tell me what is the best money/qualtity ratio?

Did i forgot annything?

Rene

 

[GM TURBO]

I was pondering this on the ride in this morning.

I have a feeling my rebuild will be coming shortly and am interested in the budget build ideas also. Of course, like every other American I want the best while spending as little as possible. I guess in some cases where the price difference is minimal - might as well get the better one Of course - that mentallity on all parts is gonna get expensive

 

[myclone]

The info I posted is/was on the Huryde(sp?) site. Im in the middle of remodelling one of the bathrooms at the house right now or Id go hunt for it. If you cant find it I'll be back and post some stuff later/in a day or two (I HATE carpentry work BTW :evil: ).

 

[GM TURBO]

I heard he bought the Carbon Fiber toilet.

http://www.syty.huryde.com/html/tech.htm

A lot of info is here on part numbers and other mods.

 

[bezerk]

So i found my gauge to measure up the bore.
it was 4.00, so next step is to bore it to 40.030 right?

about thge crankshaft, polished and nitrid, but at what size??
i wil use clevette bearings and probberbly Eagly 5.7 h-beam rods.
wich rings should i use with the JE-pistons
the thing is i life my live in holland, and i will order it out of US.

should i do something with the camshaft? nitrid, or order new aftermarket? along with the clevvete bearings.

etc. etc.

 

[bjzq8]

Boooring...

Boooring...

I think if you bore it to 40.030 you're definately going to hit water...

Sorry, couldn't resist.

There are .010 and .020 overbore pistons available in some applications, but I imagine you're going to have to take .030 if you want forgies...but I'm not really sure what the oversize availability is. One of my teachers in auto in college said that there were times that they'd get .010 pistons if somebody scored a cylinder or something...they'd bore that one cylinder while the engine was still in the car, replace the piston with a .010 over, and call it good.

Bill Jenkins
1992 Ty #1752

 

[bezerk]

Sorry my mistake,
isn''t weird that the forgies starts at .030?

annyway, can somebody please tell me what size i should drill?
going for the MM: 1inch = 25.4MM (bore it to 102.362MM)



Rene

 

[2cold]

bezerk, you own a machine shop?

 

[bezerk]

No it''s not really a machine shop, .
i own a workshop wich does in tractors/ farming machines, so we do alot in the agriculture-technic: Diesel engines, turbo's ,continiul variabel trasnmission, hydraulics, etc. etc. etc.

we rebuild engines, but the boring and most of the headwork is done to another shop, wich only does engines.
BTW Case has bushes wich is nicer to rebuild an engine, you never have to throw away engine away, unless there is an rotated mainbearing inside
We just tear out the old bushes and throw some new in it

So that''s the storie 2Cold.

 

[myclone]

Bezerk,

Just some FYI for ya on pistons..


.030 oversized pistons are the most commonly requested so thats what you see advertised most of the time. TRW, Aries, Weisco, J&E, etc all offer pistons in .010, .020, .040, and .060 oversized as well as the previously mentioned .030 over (you can also get other sizes iother than those Ive listed).

What size to buy depends on a lot of factors like bore wear, bore taper, wall thickness, and out of round bores. An .030 over bore will take care of all but the most worn or damaged bores and the pistons are readily available so thats what most ppl go for.

Another factor is that the blocks we use dont have a lot of material to reliably go bigger than .030 IMO on a boosted application without having several blocks sonic checked to find one that will keep its bore stability with a larger than .030 overbore. Some ppl have prolly done it successfully and even Ive did .060 on a 4.3 but.... it was normally aspirated and had relatively low cylinder pressure.

You also asked about piston rings. I personally like the Childs & Albert ZGS (zero gap second ring) myself and have used them in many different builds with great results. They arent the cheapest to buy but IMO they are well worth the money. Im sure Childs & Albert will have piston rings to fit just about any combonation you could come up with.

HTH a little and is not too awfully confusing.

 

[bezerk]

So the size i gave about the bore is correct in MM??
and anotherquestion.

please give me some information on the main-caps,
maybe i don''t understand this, but SyTy blocks have 2bolts maincaps right? and we prefer 4 bolt maincaps??
right? so i can just drill a few holes and make some screw........ in it??
with lining it with the 2 bolts we already have??

so somebody could give me the measurements, i can bring it to the workshop.

Rene

 

[myclone]

Sorry, I forgot that you guys are on the metric system.. All the measurements I posted are in inches but should be easy enough to convert to MM.

Im not absolutely sure what youre asking but I believe you are wanting to know what size to tell your machine shop to bore the cylinders then order pistons. That wont work for a couple of reasons.

1. The machine shop will need to measure the existing bore on the cylinders to see how much they need enlarged to bring them back to spec. In example: Lets say the existing bores measure out to 4.018 inches. Thats too large to accomodate a piston of .010 or .020 larger once the final honing was done. However, a .030 inch overbore would suffice so you now know you will need a minimum of a .030 oversized pistons.

2. Using the above example you cant just bore the cylinders .030 oversized then order pistons. Your machine shop will need to pistons in their possession so they can be measured and the EXACT final bore size calculated. The reason for this is manufacturing tolerances vary and one set of .030 pistons might actually measure .032 compaired to another set from the same manufacurer that might actually measure .029.

Also, different piston manufacturers may recommend different piston to cylinder wall clearance depending one how the piston was made and its final machining before leaving the factory.

To sum the above up you need to first measure the cylinders present bore diameter then decide which over sized piston you will need. Lastly, once the pistons are in the machinists possession they can measure them for their actual diameter and over bore the block to accomodate them.

Now on to main caps...

All production 4.3 V6 engines, including SyTys, have whats known as "two bolt mains" which translates into that the main caps are held in place by only two bolts on each one.

There are also two different types of the above mentioned two bolt main caps. Regular production normally aspirated (non turbo) main caps are of typical gray cast iron. SyTy main caps are made of a stronger nodular iron and are more desirable.

There are companies that produce 4 bolt main caps for our engines that can be easily installed by a competent machinist. These caps come in two different styles also. One usese straight outter bolts that are installed exactly like the stock inner bolts while the other type has whats known as "splayed" outter bolts. Splayed simply means the outter two retaining bolts are at a slight angle compared to the two inner bolts. The splayed type are said to be stronger since they dont thread into the main webbing of the block which in theory weakens it but instead they thread, at an angle, into the outter webbing of the block which has plenty of material to accomodate the extra bolt hole.

One last thing. I dont know if you are thinking of doing the 4 bolt main conversion at home or not, and Im sure some ppl here have successfully, but I would highly recommend that doing the 4 bolt conversion be left to a compentent machine shop. Not that I dont think you could do it successfully but just keep in mind that one mishap could ruine and otherwise good engine block. A competent machine shop has probably performed the conversion several times and is less likely to have problems given their experience.

I know thats alot of info and if you want to look at what Ive talked about you can view pic of splayed and non splayed main caps by doing a search on the net to help clarify. One company that I plan on using is program engineering as they make splayed main caps for our engines and have pics of them on their site for comparison.

HTH

 

[myclone]

I went back and read some more of this post and hopefully can provide you with some other helpful info on the questions other than pistons that you have.

You asked about what to do with the camshaft. If you are using a stock roller lifter cam then no other work is needed other than cleaning and applying a light coating of engine oil before installation. Nitriding is not need or recommended for a roller cam IMO.

You asked about the roller lifters.. That depends on what cam you are using. If you are using the stock cam or a mild cam then the stock roller lifters can be reused. If you are stepping up to a cam with more than .500 inches of lift then you may want to check into using an aftermarked hydrolic roller lifters from the likes of CompCams as Ive read on here about some ppl having issues with the stock lifters failing with high lift cams. John Waller is one person that comes to mind so maybe he can chime in with what he knows.

You asked about crank shafts.. If you are using a stock style even fire crank then there are several options depending on how much horspower you are planning on making and money you have to spend. A stock crank that has been cleaned, maganfluxed (this checks for cracks), and the journals polished will suffice for a stock or mild build IMO. If you have extra money to spend or are handy with a die grinder you can chamfer the oiling holes on the rod and main journals. Nitriding is another option of increasing the cranks strength but needs to be done before any machine work is done to the crank as Nitriding is basically a surface treatment. Cryogenic freezing is another option to Nitriding and can be done at any time as the freezing changes the properties of the crank completely through, not just on the surface. If its still there (I havent checked) then there should be quite a bit of info on the Huryde site concerning crank shaft preparation that I wont repeat here.

You asked about crank "sizes". Without getting into odd fire cranks or offset ground cranks there is only one "size". The only differences that will be encountered on a stock style crank shaft will be the main bearing and rod bearing journal size. If you are using a crankshaft that has been ground on either or both the main and rod journals you will need bearings that are oversized in the amount the journal was ground. Example: Lets say you have procured a used crank shaft that was damaged and to refinish the damaged journal(s) to spec required grinding .010 inches off the journals. This will designate that you now need a bearing insert that is .010 thicker to make up for the removed material from the journal to keep the bearing tolerances in spec. Bearings are most commonly available in .010, .020, and .030 inch over sized as well as many sizes in between the three Ive listed. The only way to know what size bearings for the crank shaft will be needed is to measure the journals with a micrometer to determine how much or if any machine work is needed and finally purchase bearings accordingly to bring the clearances into spec.

HTH somemore.

 

[bezerk]

Thanks for all the info.

About the rebuilding and the budget.
Since i life in the Netherlands, and aftermarket product are rare for US vehicles, I WOULD PROBBERBLY go with some HQ-parts.

So this is what i probberbly would do, please give comment if you don''t agree/agree:


Bring the block to the workshop, and let them find a Bore for Cil.walls

Bring crankshaft to workshop and let them polish it

make a phonecall to the shop that does my engine and ask for bore.

order 4bolt main caps, and the pistons for the bore, also H-beam Eagle rods

call with the workshop that did my crankshaft and ask them wat they did with the measurements, and order bearings depending on what they found out. also bearings for cam-shaft.

maybe order vortec head along with welded intake (have read an post about this one, but everybody has his own meaning about going with stock rockers/lifter/springs) So don''t know about that one yet.

:drinking: Wait for Sigo and his parts and drink beer with him.

drop ordered pistons and mainbearingcaps at the workshop.

pick up everything i left at the shops.

start building.

:roll: please tell me what you guys mean with balancing????

:angel: Happy bezerk

Don''t know how to make fancy dots

Rene

 

[myclone]

It looks as though you have a sound plan as long as the machine shop is well equipped and knows what they are doing.

You asked about balancing.. When a production engine is assembled it is done so with parts that were manufactured to work with one another to begin with. The pistons, rods, crank shaft, harmonic damper, and flywheel were all designed to work in harmony in a stock application.

When an engine is rebuilt with other that factory replacement parts and/or parts from different manufacturers (like Eagle rods and TRW pistons) these parts are not of the stock components weight that they replaced. If an engine is not balanced then the rotating assembly may exibit vibration that is at a minmum an annoyance or at maximum something that can destroy the engine. What having a machine shop "balance" an engine achieves is to weight match the piston and rod combo to the optimum and then match the piston/rod combonation to the corrosponding position on the crank that will yeild the closest reciprocating mass to counter the weight of the piston and rod. Most if not all the time no amount of swapping pistons, rods, and positions on the crank will yeild a good balance so the machine shop must either remove or add metal to the crank shaft counter weights to closely match the reciprocating mass of the piston(s) and rod(s).

To sum all that up... When you replace any of the rotating assembly components with other than stock the weight of those components now does not match what the crank shafts counter weights were made for so the engine must be rebalanced to accomodate the new parts.

There is actually more to the process like removing material from the pistons and rods to help with the balance but the above should give you an idea of what the machine shop does when you request the engine to be "balanced"'.

One last thing.. Be sure to provide the machine shop that does the balance with the harmonic damper and flex plate you will be using in the final assembly as those components make up part of the rotating assembly as well.

HTH...

ps Sigo and yourself need to down a few cold ones for me too if you please

 

[TurboManiacal]

Dang, this is a lot of information to digest. Now to put it all together into a coherent shopping list of parts to build what should be a budget / correct build.

I've got a set of intakes that have been welded for vortecs. I'm willing to trade him intakes and get him vortecs. Shopping list next post.

 

[bezerk]

So i have phoned to a company wich does alot of tuning, and they can balance the assambly, but as you know i want to nitred the crankshaft, and let them polish it.

But.... this will cost me abot $450. the problem is that they must polish it, and than order the bearings, is there a way i can buy a crankshaft wich is already balanced and nitred? so i can order everything in one time?
and should it be save if i just buy the JE-pistons for #30 oversize?
the company told me it would be save because it''s a large oversize


this will save me a few weeks of waiting.
and would save some work.
and alot of traveling

Rene

 

[TurboManiacal]

Rene,

Here's the post on the prep of the intakes for Vortec Heads:

http://syty.net/phpBB2/viewtopic.php?t=22799&start=0&postdays=0&postorder=asc&highlight=

Working on getting a parts list put together.