SBF 347 Wiseco Forged 4.040" Bore
$579.00
Available
Variants:
Flat-Top (0cc) [KP490A5]Dish-Top (-10cc) [KP491A4]
Flat Top (-6cc) [KP490A4]
Wiseco Forged Pistons, 4.040" (.040" over) Bore Size
For SBF 347 - 5.4" Bushed or Press Fit Rods, H-Beam or I-Beam and a 3.4" Stroke Crank.
We have built approximately 15,000 engines using Wiseco pistons over the past 10 years. The engines have been for street rod and strip use, and we have seen no problems or complaints. They are an excellent product in every respect.
These pistons are for use with full floating bushed rods or press fit.
Our custom-made Wiseco pistons are highly regarded in the street/strip performance industry. Wiseco typically offers several grades of pistons, starting with the lower-grade Pro-Tru Street version made with 4032 forged alloy. The next level up is the professional series, which is more expensive and made from 2618 aircraft alloy with fully machined crowns rather than the as-cast crowns found on the Pro-Tru series. Our Wiseco pistons are custom-made for us and feature both premium elements: 2618 alloy and fully machined crowns. All premium-grade forged pistons on the market have these two unique features and usually cost around $800-$1100 per set.
Important Note
Many customers ask what size they should bore their block to allow for proper piston-to-wall clearance. The required clearance is built into the piston already. For example, if these pistons show a given size such as 4.030, that is exactly what you will bore the block to. The actual size of the pistons, when measured at the skirt, 1/2 inch above the tang, will show to be approximately 4.026. The needed clearance is built in. If you are using these pistons in a marine application where the boat receives its water from the lake, then an additional 1.5-2.0 thousandths would be added to your final bore size. Some forced induction applications may also require a slight increase in bore size.
These pistons are suitable for use with mid-level nitrous or blower setups. Extreme level builds that are making HP numbers in the 1000 HP range will require a set of custom-made extreme duty pistons.
Our custom made Wiseco pistons have a compression height that is .015 taller than nearly all catalog pistons on the market. We find this to be a very valuable feature. Since our pistons sit at a taller than normal compression height, you will only have to remove approx. .010 off the deck surface of a virgin block to achieve a zero deck. This also allows for future deck re-surfacing and still not ending too far below stock deck height.
Leaving the deck on your block thick makes for a stronger block that resists flexing and also runs cooler, as the deck thickness has a lot to do with the dissipation of heat. Blocks with decks cut down to any great amount are also prone to cracking. This is why our pistons are designed to sit flush, (zero deck) at .010 below stock deck height.
Since nearly all catalog pistons on the market sit .025 below the surface of a virgin block, the only way to achieve a zero deck using such pistons would be to cut .025 off the deck surface. This compromises the integrity of the block, in our opinion. Should you decide to leave the block deck higher up, using such pistons creates a new issue of having a very poor quench/squish zone. The only way you could really take advantage of a catalog piston is by having a block that needs to or has already been butchered down to 9.00 deck height. At that point, we don't think you should not use such a block. Having the piston sitting flush with the deck is very desirable, regardless of the fact that your overall compression ratio is slightly higher than if it were sitting below the deck.
We have found that 95% of our customers are using a virgin block or a block that is close to stock deck height. This is why we have designed our pistons to have a taller compression height. On very rare occasions, you may end up with a block that has the piston out of the hole by a few thousandths and this not a problem at all. Most head gaskets are approx. .040 thick, and should you end up with a quench zone of .035, then that is perfectly ok. If the quench zone ends up too far below .035, then there are plenty of .050 thick head gaskets on the market. One more benefit to this is that most machine shops charge much more to deck a block down from stock deck height to 9.00 than they would to do a light cleanup, and that's all that's needed when using our Wiseco pistons.
Another great feature about our pistons having a taller compression height is that the ring land above the top ring is much stronger by being .015 thicker. When pistons encounter the effects of detonation, it is not uncommon to see pistons with the ring land above the top ring broken off. The thicker ring land also makes a better heat sink.
You may have noticed that our Wiseco custom made forged pistons are referred to as Racing Pistons on the package. This does not mean that the pistons are for racing only. This is a generic term, referring to their ability to be used in high performance applications as well as for street rod use. These pistons are perfectly designed for use on the street, as well as for medium to upper level drag racing.
Our custom made Wiseco forged pistons are made from 2618 aircraft alloy. We find this alloy to be much more suitable for high performance engines than the common 4032 forged alloy. You will usually see the higher end pistons on the market using 2618 aircraft alloy.
Why go with 2618 forged pistons? If you encounter certain tuning issues, detonation is highly probable, and its effects can cause severe damage to your engine. The 2618 forged piston is able to withstand the damaging effects from detonation to a higher degree than the lower cost 4032 forged pistons, especially non-forged hypereutectic pistons such as Speed Pro or Keith Black, and many others.
Our Wiseco forged pistons will clear most any valve size on the market with ease even with the use of large lift cams.
You may have noticed that our Wiseco custom-made forged pistons are referred to as "Racing Pistons" on the package. This does not mean that the pistons are for racing only; this is a generic term referring to their ability to be used in high-performance applications as well as for street rod use. These pistons are perfectly designed for street use, as well as medium to upper-level drag racing.
Our custom-made Wiseco forged pistons are made from 2618 aircraft alloy. We find this alloy to be much more suitable for high-performance engines than the common 4032 forged alloy. You will usually see the higher-end pistons on the market using 2618 aircraft alloy.
Why go with 2618 forged pistons? If you encounter tuning issues, detonation is highly probable, and its effects can cause severe damage to your engine. The 2618 forged piston can withstand the damaging effects of detonation to a higher degree than the lower-cost 4032 forged pistons, especially non-forged hypereutectic pistons such as Speed Pro or Keith Black, and many others.
Our Wiseco forged pistons will clear most valve sizes on the market with ease, even with large lift cams.
Wiseco fully forged pistons rated at 700+ HP. This is a full set of pistons. Wiseco pistons are 100% manufactured in the USA 🇺🇸 and are one of the highest-rated pistons in the country.
Very Important Note!
Feel free to ask any questions you may have about these pistons. Many questions revolve around whether we have pistons for specific applications. Please check our wide variety of pistons to see if what you need is listed before asking if we have a particular size. Be absolutely sure that you select the correct bore size and piston volume before purchasing. It is also important that you know what rod length you have. The rod length required is clearly stated in the ads. When searching for various size pistons, you can simplify your search by using common keywords in the search bar. We update the technical information in our listings regularly.
Product Information
| Product Type | Piston |
|---|---|
| Price (excl. tax) | $579.00 |
| Price (incl. tax) | $579.00 |
| Tax | $0.00 |
| Availability | Available |
| Engine Block | SBF |
| Bottom Ring Land (in) | 0.09 |
| Brand | Wiseco |
| Pin Lock Type | Spiral |
| Piston Bore | 4.04 |
| Piston Compression Height | 1.102 |
| Piston Material | 2618 Forged Aluminum |
| Piston Oil Ring Groove | 3/16" |
| Piston Second Ring Groove | 5/64" |
| Piston Stroke | 3.4 |
| Piston Top Ring Groove | 5/64" |
| Piston Type | Forged |
| Piston Weight w/o Pin | 450 |
| Ring Set # | 2M139030 |
| Second Ring Land (in) | 0.17 |
| Top Ring Land (in) | 0.255 |
| Wrist Pin Diameter | 0.927 |
| Wrist Pin Weight | 122 |
| Shipping Cost | 24 |
| Number of reviews | 0 |
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