OK, I'm actually to the point where I'm starting to budget and plan for my engine build this coming winter. Hopefully. I'm gonna layout my very basic thoughts/plans, and then explain my question.

I'd like to build the engine myself, from the bare block from the machinist. I'd also like to keep my original L98, which although still running strong, has over 170k miles on the shortblock. Plan is to build a 275-300 rwhp TPI/HSR/MR/SR type motor. Nothing insane.

So I take the motor longblock to the machinist. He does what he does, and gives it back.

Now what? Is it likely I can reuse my crank? I see rotating assembly kits in summit and jegs, but they don't come with all the rebuild kit parts. Vice versa, the rebuild kits don't have cranks, and some don't have rods or pistons. The absolute LAST thing I want to do is piece it together, rod by bearing, by piston, by ring, etc. etc.

I've been reading book after book on the build, but the shopping is what I'm a little unsure about.

Thoughts???

Thanks,
Boob

 

#1 Estimate a budget then triple it.

#2 Take the block and the entire bottom end to the machine shop. Crank, rods, pistons etc and let them put it together. You don't have the tools or experience to make sure tolerances are correct. Bearing clearances are critical and if you screw something up, your engine will cost even more to fix a second time. A good machine shop won't even bore the block without having the pistons that will go back in.

When you get the short block back from the machine shop all assembled, you put in the cam, heads etc to finish the engine. Assembling the top end isn't as hard as making sure the bottom is done correctly.

#3 Buy any type of crate engine already built to the performance level you want. It can be anything from a factory replacement to a full race and anything in between. It will probably end up cheaper to buy an already assembled engine than what it costs to build one.

 

...yeah....sorta what I had been thinking. I'm actually glad you said what I had been thinking.

...Out of principle, I can't buy the crate engine. Gotta turn some wrenches, even if it's just on the top end.

Do you think a pre-assembled shortblock is a viable option? I'd like to use the original motor, but not the extent that I want to pay MORE to do so. I'd just keep the OE motor just in case of course. ....guess I could make some calls and find out.

 

Oops. My mistake. Get the short block back from the machine shop and assemble the rest.

If you have the option to pick up a short block, that can be a cheaper alternative. Typically, the shortblock will normally be a factory replacement style with nothing special in it. It will come with a camshaft. If you can pick up a mild performance version, it would be better. If not, you'll probably change the cam to something better. How much cam depends on so many other things. With a shortblock, you can put any head on the engine so the cam can't have more lift than the head can handle and the cam can't produce more lift than the valve clearance from the pistons will allow.

Since your bottom end isn't damaged, it can still be rebuilt but labor and machine shop costs to rebuild an engine can cost close to what a short block or complete replacement engine can cost. Start adding goodies into the engine and they'll all cost more.

Price out a set of replacement heads and price out a set of assembled aluminum heads. Then get a quote from the machine shop what it will cost to do a valve job on your old heads. Depending on your cam choice, you'll probably need new springs also. Replacement heads can be cheaper than all the machine shop work, depending how much work they need.

The only way to know which route to take is to get price quotes for new stuff and for machine shop work. You won't know exactly what your engine needs until it's stripped down and inspected. If the cylinder bores show little to no wear, it might be a simple clean up, new rings and bearings then reassemble. Install a better than stock camshaft. Probably get a valve job done to the heads. Expect to pay at least a thousand dollars just in machine shop work but that also depends on what work needs to be done. Don't be surprised to find out to completely rebuild the engine the way you want will cost $3000+

 

I don't know if this will help with any decisions. But I'm in the process of a H/C/I swap. I didn't touch the bottom end.

AFR Heads - $1,439.00
HSR & Fuel Rail - $844 (I got the polished version)
Cam - $265.95

Total: $2548


Now, with all the other things (Gaskets, rocker arms, timing chain, pushrods....etc)

Final total: $4129

 

Thanks for the input guys.

I had the heads cleaned up, valve job, and springs done when I swapped in the ZZ4 cam a few years back. I wouldn't mind a little more power, and I wouldn't piece of mind with that OE bottom end being so old. That the reason for the build, and I'm just trying to figure out the best way to do it.

Thanks.