WISECO FORGED PISTONS 4.165 BORE SIZE FOR SBC CHEVY 406 408 ENGINES, FLAT TOP FOR USE WITH 6.0 BUSHED OR PRESS FIT RODS. The correct size rings used with these pistons is listed below in the piston spec chart. We offer the correct rings for these pistons in our other listings. We strongly recommend our Total Seal ring pack. The part number is # CR0690 40 DROP IN.
We have used these exact series of rings in our engines for many years. Our custom made Wiseco pistons are rated very high in the street/strip performance industry.Wiseco normally offer several grades of pistons, starting with the lower grade Pro-Tru Street version made with 4032 forged alloy. The next level up would be the professional series that are much more expensive and made from 2618 aircraft alloy and have fully machined crowns rather than the as cast crowns that are on the Pro-Tru series.
Our Wiseco pistons are custom made for us, and have both of these premium features, 2618 Alloy, and fully machined crowns. We have built approximately 6000 engines using the Wiseco pistons over the past 10 years.
The engines have been for street rod and strip use. We have seen no problems, nor have there been any complaints. They are an excellent product in every respect. Many customers have asked us what size they should bore their block at to allow for a 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 then 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 approx. The needed clearance is built in. Should you be using these pistons in a marine app. Where the boat receives it's water from the lake, then an additional 1.5-2.0 thou. Would be added to your final bore size, and some forced induction apps may also require a slight increase in bore size.
These pistons are totally 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. The calculations below assume your pistons are at zero deck.
Let's say your compression calculates out to be 10.50 for example based on having the pistons at zero deck (flush with the deck), but your pistons were going to be. 005 in the hole, then the comp. Ratio would only drop to 10.36, and if left. 010 in the hole, then it would drop to approx. 10.22 We do recommend having your block decked to allow the piston to set anywhere from flush (zero) to.005 in the hole for optimal performance. We used a 4.125 head gasket diameter, and a. 040 head gasket thickness in our calculations to come up with our comp. We have highlighted in red the compression ratio for the bore size and piston volume using several popular combustion chamber sizes. Our Wiseco Forged pistons are custom designed with an increase in compression height.
Here are a few facts about compression height and deck height. 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 good feature about our pistons having a taller compression height is that the ring land above the top ring is much stronger by being. 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. These pistons are also suitable for use with nitrous systems up to approx.250hp and superchargers up to approx. For the slight increase in cost, this is the best value on the market. WISECO FULLY FORGED FLAT TOP PISTONS RATED AT 700+ HP. WISECO PISTONS ARE 100% MANUFACTURED IN THE USA. THEY ARE ONE OF THE HIGHEST RATED PISTONS IN THE COUNTRY. These pistons are for use with 6.0 full floating bushed rods, or press fit. The compression height is 1.140 -4.5cc Flat top with 2 valve reliefs.
Ring groove size 5/64 5/64 3/16. See full piston specs below. CHEVROLET - Small Block V8. TOTAL SEAL CR0690 40 DROP IN. We offer these pistons in flat or dish style as well as dome top, and most other bore sizes.
Feel free to ask any questions you may have about these pistons. Many of the questions asked are if we have pistons for certain 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 key words in the search bar. We update the technical information in our listings on a regular basis. We are not responsible for collateral damage caused by the use of this product. The RGA number must be included on the return label. Even though you may have explained the problem to us, and been granted permission to return the product, we must have a written explanation and a contact number included with the product. It is also recommended that you include the name of the person from our company that you have been in contact with. Following these guidelines will make the return process work as it should. UPS is our primary shipper. UPS delivers Monday - Friday, except for national holidays.