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Discussion Starter #1 (Edited)
Hi,

I'm still in the process of planning a 351W build. I found an ad for a 408W shortblock for $1,000. Here is the description:

Rotating assembly is eagle 5140 cast crank, I-beam rods with 3/8 arp cap screws, Keith black -27.5cc dished full floating pistons. 74 Block with arp main studs new cam bearings and freeze plugs. Rotating assembly is brand new. Block is fresh.The engine was apart when i got it. I assembled it and have all the specs. Rings are gapped for up to 150 shot of nitrous. Compression ratio would be roughly 9.3:1 with a 60cc head.. Balanced to 28oz. I'm looking to get 1,000
I have not contacted the seller to see if he will negotiate, but with the block, rotating assembly and pistons, there is at least $1500 worth of parts in the shortblock.



What type of heads could I run with these pistons? What does it mean when the rings are gapped for nitrous? Does that just mean that they can withstand a nitrous shot if one were to run a nitrous setup?

I have a 351W engine from an '86 Ford truck. The heads are useless as far as I am concerned, especially since there are a lot of rusty bolts stuck in there. I feel like I could get ahead with buying a fresh, assembled shortblock, and just sell the stock engine I have now.

Any help is really appreciated because I am an engine newbie!

Thanks,

Justin
 

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The stroker kit alone is $1100. However, I always wonder how much faith you should put on someone who you don't know built the engine. I am about to start building my 408 and I have been looking around as well. Proper machine work on a block around my part of town is $600 plus the stroker kit $1100 plus the block $200 = a lot of cash! Good luck!
 

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Buying used motor parts, and used speed parts, is always a crapshoot. You might score, and you might get stung.
 

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If it's done right, that is a steal! My machine work was $1K alone on a 5.0
As far as ring gapping for nitrous, if they are running Hyperutectic pistons, the top ring has to have a larger than normal gap. I am running the Keith Black Hyperutectics and it states to run about .028-.032 gap. Stock is something like half that. Went online and did some reading and some builders are saying go as much as .035 and you will still not lose any compression. So I set mine at .035 just to be safe.
The hyperutectics actually collect heat at the top ring grove area and will make the top ring run at a higher temp. not enough gap, and you lose the top of the piston! Go check out Keith Blacks website on their tech pages.
With the pistons you have in that shortblock, I would say any stock type head, but not Twisted Wedge heads. A good set of AFR 180's or better is needed for that many cubes. Anything smaller (CFM flow numbers) will choke down the potential of having a 408. Your going to need a good breathing intake too. Edelbrock Air Gap Performer RPM would be a good choice, along with some good port matching. That 408 is going to want to breath freely. Oh, good set of headers is a must too!
EDIT: Ask seller if he had the rods resized after installing the rod bolts. If not, run from it. Rod MUST be resized after rod bolts are swapped out.
 

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If it's done right, that is a steal! My machine work was $1K alone on a 5.0
As far as ring gapping for nitrous, if they are running Hyperutectic pistons, the top ring has to have a larger than normal gap. I am running the Keith Black Hyperutectics and it states to run about .028-.032 gap. Stock is something like half that. Went online and did some reading and some builders are saying go as much as .035 and you will still not lose any compression. So I set mine at .035 just to be safe.
The hyperutectics actually collect heat at the top ring grove area and will make the top ring run at a higher temp. not enough gap, and you lose the top of the piston! Go check out Keith Blacks website on their tech pages.
With the pistons you have in that shortblock, I would say any stock type head, but not Twisted Wedge heads. A good set of AFR 180's or better is needed for that many cubes. Anything smaller (CFM flow numbers) will choke down the potential of having a 408. Your going to need a good breathing intake too. Edelbrock Air Gap Performer RPM would be a good choice, along with some good port matching. That 408 is going to want to breath freely. Oh, good set of headers is a must too!
EDIT: Ask seller if he had the rods resized after installing the rod bolts. If not, run from it. Rod MUST be resized after rod bolts are swapped out.
Why not twisted wedges? It would cost No more then $50 to have the pistons notched, and depending on the cam, that may not even need to be done.
 

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Justin, I saw that same ad. IIRC the person selling it owns a machine shop (or builds motors), as the motor was a payment for work he'd done previously. Sounds like a good deal assuming this does come from a shop. I'd have jumped on it if it weren't so far away from me. He said he'd ship but that'd be a bit much.
 

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The question again would be if the work that has been done, has been done right.....My machine work alone was 1200.00. That included turning the crank .10, boring the cyls, cleaning up the crank journal bores, assembling pistons to rods, re-size rods, check block for cracks and complete rotating assembly balance...
 

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"Why not twisted wedges? It would cost No more then $50 to have the pistons notched, and depending on the cam, that may not even need to be done. "

I guess it could be done after the fact. I bought TW specific pistions for my build though.
 

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"Quote:
Rotating assembly is eagle 5140 cast crank, I-beam rods with 3/8 arp cap screws, Keith black -24cc full floating pistons. 74 Block with arp main studs new cam bearings and freeze plugs. Rotating assembly is brand new. Block is fresh.The engine was apart when i got it. I assembled it and have all the specs. Rings are gapped for up to 150 shot of nitrous. Compression ratio would be roughly 9.3:1 with a 60cc head.. Balanced to 28oz. I'm looking to get 1,000"



That is a good deal for an assembled short block with CAST internals. I would not go with cast internals though. And I would not use a 150hp shot on KB Hyper pistons. Save some money and buy all forged or better internals. You will be happier years down the road.
 

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Discussion Starter #11
"Quote:
Rotating assembly is eagle 5140 cast crank, I-beam rods with 3/8 arp cap screws, Keith black -24cc full floating pistons. 74 Block with arp main studs new cam bearings and freeze plugs. Rotating assembly is brand new. Block is fresh.The engine was apart when i got it. I assembled it and have all the specs. Rings are gapped for up to 150 shot of nitrous. Compression ratio would be roughly 9.3:1 with a 60cc head.. Balanced to 28oz. I'm looking to get 1,000"



That is a good deal for an assembled short block with CAST internals. I would not go with cast internals though. And I would not use a 150hp shot on KB Hyper pistons. Save some money and buy all forged or better internals. You will be happier years down the road.
How important are forged internals for a street engine? I don't plan on any drag racing or any days at the track.
 

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Discussion Starter #13
Ask seller if he had the rods resized after installing the rod bolts. If not, run from it. Rod MUST be resized after rod bolts are swapped out.
The seller said:

They are eagle/arp bolts they came with the rods from eagle so they would have handled the resizing there if they needed it.
I am going to give him a call tomorrow night.
 

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there are alot of nice pieces of advice here - if it were me and it was within a reasonable drive (as it is with you) - I would buy it. Once you have it home do a full disassembly and check all tolerances. Also make sure nothing was nicked during the original assembly. Balance the assembly - a static blancing atleast and plastigauge everything during assembly. By the way why is the guy selling it?
 

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You will be fine, especially in a street car. People get way too caught up on everything having to be forged now days.

X2 You will be fine in a street car. And people get caught up with having everything forged for a very good reason, 2 words "bullet proof".
 

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there are alot of nice pieces of advice here - if it were me and it was within a reasonable drive (as it is with you) - I would buy it.Once you have it home do a full disassembly and check all tolerances. Also make sure nothing was nicked during the original assembly. Balance the assembly - a static blancing atleast and plastigauge everything during assembly. By the way why is the guy selling it?
Great advice there. In addition, during disassembly...I would cycle each rod (loosen, knock free of the interference fit, then retorque) a half dozen times, then take them out and check them for round.

Additionally...when deciding on a cylinder head...keep in mind you have half an inch more stroke than stock. You need a cylinder head with a substantially larger intake cross section (FORGET PORT VOLUME!). A TW 170 is equivalent in size to an AFR 185, and will out perform it. If you were my customer (I'm not in business anymore lol), I'd suggest something even larger...perhaps a Fast as Cast 195. Since you're not racing, look at 'rv' type cam events designed for a big block, then look for something similar in a Windsor architecture (I personally would suggest a bit larger...but that's up to you). I would call a single plane and a 700cfm+ carb a must (if using the FAC 195's.. a 700cfm carb would work well). Also necessary are 1 3/4" or larger headers.

Don't get caught up in the 'small block' classification of your motor. You have a motor with more stroke than most big blocks out there...and in order to keep a usable, stock type powerband, you need to feed it as if its a big block. Unfortunately small block dual planes, 1 5/8" headers, and 650cfm carb just don't cut it. If you follow the above recipe, you'll have stump pulling torque off idle, and pull hard all the way to a 5500-6000rpm shift point...all the while keeping a silly stupid grin plastered across your face :).

Cris
 

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Solid advice Cris. A stroker motor loves to BREATHE and too many people choke it by sticking with the small block assumptions. I may even go up to a TW 205 or find a set of Rs or Highports, although you get into issues finding headers within reasonable price.

I'd also recommend going with a custom TLSR cam from Jay Allen
 

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Solid advice Cris. A stroker motor loves to BREATHE and too many people choke it by sticking with the small block assumptions. I may even go up to a TW 205 or find a set of Rs or Highports, although you get into issues finding headers within reasonable price.

I'd also recommend going with a custom TLSR cam from Jay Allen
Normally, I'd recommend Jay as well, he supplied our cams for Pete Anderson Racing. I don't believe he is taking orders however...due to health issues.

I just sold a set of 225cc Highports that were on my daily driver 347. I went to something substantially...larger :).

Cris
 
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