Help me build my first motor.

[Detective Coating]

Looking for some help on my first engine build. I am trading my 6 bolt turbo bare block for a NT block with a 20 overbore and need to put together a parts list for a reliable but fairly inexpensive build. This won't be being done till january or so but I wanted to do some research and find out pro's and con's on different piston/rod combos. I plan on using the stock 1g Rods but I will have to use forged pistons because the lack of oil squirters.

I eventually plan on jumping to a bigger turbo, possible a 60-1 or HX35. I'm trying to find a good build that will handle around 400hp reliably. I know my 7 bolt can handle it but I'm building this block as a learning experience and a just in case for when the 7 bolt decides to go. So does anybody have any recommendations for pistons, gasket sets, etc. I plan on using a new OEM crank and pretty much everything else will be OEM because from what I have been reading that is the best way to go.

I'm not looking to be spoon fed by any means. I just want some people's opinions on the way to go about this as this is my first build. I know where the search button is

 

[TOONAH]

I decided to use Eagle rods and Mahle pistons on a new Topline crank. I choose ACL Race bearings because they do not have the final sintered layer. The sintered layer is a very hard thin metal and is not supposed to wear off during the life time of the bearing. However, bits of it have been known to flake off, especially on the thrust bearing. These bits get in between the crank main journal and the bearing and chew it to shreds. I have photos of the damage if you are interested. I choose Mahle pistons because of their incredible capability of surviving 1.5 thousandths piston side wall to cylinder clearance.
I had my machinist set up the bores for that spec. That is .0015"!! This provides for superior compression anti-leak down and minimal piston slap. Now having said all this, what I need to impress on you is that the machine work that will need to be done to the block is of vital importance. The Mains must be align honed with a torque plate. The cylinder wall concentricity must not vary by more than .001". The final hone job is critical.
Hence you must find a reputable and skilled machinist to do the work. He will (or should) ask you for the crank, the bearings and at least one piston. If you build it yourself and you have never done an engine before, you can make some fatal mistakes. Like installing the upper main bearing into the bearing cap. This will prevent proper lubrication. The mains girdle on a 7 bolt is a bi*** to align. If you do not do it right you may get premature thrust bearing failure, AKA "The Dreaded Crankwalk". I could spend all night sharing what I know about engine building, but I am only an amateur too. I am a professional mechanic,
but I build Positron Emission Tomagraphy scanners for a living, not engines.
If you have any specific questions, myself or others will be pleased to help you.

 

[VETTE_50_TH]

Why did you trade the turbo block for a NT block btw? On my build, even though people say you dont need the oil squirters, i still put them in and i have forged pistons. There is nothing wrong with doing that. On a basic build, why do you do a 2g piston with a skirt coat and a 1g big rod shotpeened? That would suffice.

James

 

[turboking15]

if its not a motor that needs to go into a car right away i would just save up a little more and get some nice rods as well. the 1g rods are great, but if youre in there now build it once to handle anything you can throw at it so you wont have to build another block when you outgrow the 400 hp range.

 

[1992awdlaser]

What I would do for a budget build:

Mahle Piston and Eagle Rod Combo (2.0/2.3) - Modern Automotive Performance
Topline Complete Gasket Set DSM - Modern Automotive Performance
Topline Freeze Plug Set DSM - Modern Automotive Performance
Complete DSM Timing Belt Replacement Kit - Modern Automotive Performance
ACL Race Series Main and Rod Bearings (DSM / Evo) - Modern Automotive Performance
Topline Water Pump DSM - Modern Automotive Performance

-OR-

Your choice of piston
Topline Complete Gasket Set DSM - Modern Automotive Performance
Topline Freeze Plug Set DSM - Modern Automotive Performance
Complete DSM Timing Belt Replacement Kit - Modern Automotive Performance
ACL Race Series Main and Rod Bearings (DSM / Evo) - Modern Automotive Performance
Topline Water Pump DSM - Modern Automotive Performance
Eagle Forged Connecting Rods / DSM & Evo - Modern Automotive Performance



You could get away with the stock rods for a little while. But I would rather build it once, build it right.

 

[Detective Coating]

Wow, thanks for all the links. I planned on going with Mahle after talking to Jeff at Slowboy's. I will keep all of those in mind. I need to really start saving because I wrecked my car and that is more of my focus to get done now.

 

[BoredDSM]

The Mains must be align honed with a torque plate.

Do you mean the cylinders have to be honed and bored with a torque plate? The mains just need the caps torqued to spec.

Sorry to hear about your car hope the build goes well. Should look into a nice set of h-beams that would give you some more room to expand later on if need be.

 

[TOONAH]

When considering Mahle pistons as I did, one has to consider that they are the lightest
piston on the market for a reason. It is not just the weight of the alloy. The Mahle piston has less 'skirt' surface area than any piston out there. Like any good marriage, the form and fit of the piston and the cylinder has to be near perfect. If the mains bore is off even by a few thous in relationship to the stroke alignment in the cylinder bore, some part of the piston skirt will rub on the cylinder wall. Consider also that I had, by Mahle's recommendation, my machinist set up the final hone so that the piston side to cylinder wall
clearance was 0.0015". That's right! One and half thousandths. You can see why the mains bore has to be honed with the girdle (this is a 7 bolt) torqued to spec with Arp main studs
and a torque plate bolted down (in place of the head) to 80 ft lbs with Arp head studs. The 4G63 block like many others suffers from torsional stresses. I believe in pre-stretching Arp hardware. Some old timers claim you should torque heads down, loosen and retorque ten times!! As long as you do not over torque the Arp studs, there is no harm done. Course some may disagree. Mahle pistons are not for the faint hearted. Getting the piston pin locks in is a chore. No matter what you do, you end up scratching the piston. You must not use an expander tool on them. That part of the piston does not come into contact with the cylinder so who cares about a scratch there. Piston slap is a real problem even with 0.005" piston to wall clearance. I had to beg my machinist to do a 7 bolt. He said I was nuts considering the crankwalk issue. But I believe improper clutch use has a lot to do with crankwalk. I am not building a drag car. It is just going to be a slick show car that has all the bells and whistles. I am not interested in going faster. I want to go faster, faster!!!
Good luck with your Mahle pistons. Once again, I highly recommend that your machinist do a mains hone/alignment with torque plate in place. The final hone should be of the lightest grade.