Nick's 308 to 4.0 conversion

I have responded to this post back in December to explain the depths of my personal neurosis regarding the 308 and to provide a forum for people to say “what if we try this”.

Some of the feed back has been very encouraging. Some of have try to seduce me into a pissing contest about stupid stuff. Perhaps it would be helpful if I just stipulate that I am jerk and maybe not to smart so that we can move on and discuss some really interesting issues. By the way, I am not inclined to make any reference to penis size.

The following are some the things that might be of interest right now to those that are either rebuilding or contemplating an engine overhaul:

1. How much distortion is occurring in the sleeves and where is it coming from? I personal was interested to learn that simply bolting on the bellhousing distorts the outside cylinders. This would tend to confirm that these blocks move all over the place and explain some of the oil control problem. The advantages of boring and honing the sleeve in the block would seem to be an interesting topic for discussion. This may seem a little self-serving because Steve is the only one that is doing a block in this manner, to my knowledge. This is a legitimate question. Is there a better way of putting a 308 together?

2. What happens to the metallurgy of the sleeves wearing surface after it has been cryogenically treated. It would appear that there is less austenite and more martensite in the metal. My question is how much would this reduce cylinder wear and increase the long term sealing capacity of the cylinder. What is the value of reducing cylinder wear by about half?
I would also like to know if cryogenic treatment alters the frequency in which the sleeves rings. With every combustion pulse the sleeve will ring like a bell. The ringing can cause cavitations of the coolant which actually erodes the exterior of the sleeve. The extra viscosity reduces cavitation. This one of the un-discussed benefits of Evans coolant.
3. We have determined that steel rings would be the best solution for this project, but we have debated which coating would provide the lowest coefficient of friction and the longest useful life. New Japanese car’s have titanium nitrite coated rings that are very narrow. This is done to increase mileage. We have looked at various alloys of chrome, and even DLC products and other stuff. Some of these coatings have properties like extremely low coefficients of friction and high Rockwell numbers. This interests me because so much energy is wasted as moving metal parts rub against one another. Some of these coatings provide lubrication that is superior to motor oil. Some of these coatings are so new that that have only been used in high-end race engines. We have also debated how narrow the rings should be. Nick’s car was setup rather conservatively, but the 4-liter may not be. There have been discussions about the various options for coating piston shirts and tops. Nothing is absolute, but the goal remains to do the best that we are able.

4. One of the most interesting things to come out of all of this is the discovery that most of these V8 family members can share the same head gasket. When I was told this I nearly wet my pants I was so excited. Nobody else out there picked this up or seemed to care. This revelation came from the manufacture of the MSL gaskets. They had been sent various cylinder heads and blocks. The conclusion was that one head gasket could be used interchangeable for the 2V, 4V, 348, and 355 heads. Is anybody wetting there pants yet? Let me give you a hint, the studs are in the same place. The oil return passages aren’t, but the studs are. Maybe with a little welding and machining and if we scratch our balls long enough someday there might be a 4-liter engine with 355 solid lifter heads setting on top.

In the past there are those that have been quick to state that most of our new ideas are impossible or just flat wrong. Who knows, they may be right, but it sure is fun to ask what if and dream of the possibilities.

Mark Lewis

 

Krowbar, the bore is the same in the 3.5 as the 4.1 SO GET OVER IT! All development that I am working on as of now will most likely apply to Marks 4.1. that he is doing. The water pump is $695.00 has been since they were available, not everything is priced on my website NEVER HAS BEEN. Keep in mind that I am not running a race to get this car finished for F chat. My project started in May of this year the car was at the Concorso Italiano in August with the engine in it, that is not a long time. Any engine builder & installer on this thread including Kermit can attest to that. Everybody busted their balls to get this project ready for the show, now we need to complete the car as a package. This engine will have to be broken in before I can even take it to the dyno. Once it gets to the dyno there will be still development work after that & will have to go back probably quite a few times.


Newman for some Clarification, It was Kermit who built motorcycle engines not I.

Kermit there are KV’s on the car as they work for eliminating the pressures in the engine & a pair the generic ones are only $110.00 from ET Performance, I pulled those ones pictured off Isabella’s original engine as we were in rush to get the car ready for the show. I do not believe they actually make any more noticeable power. I do thank you for your complements with respect to the engine. Regards.

 

There has been a constant drum beat that this thing is way too expense. Heck, it very well may not be for every wallet or every 308 engine bay. The reason that I mention it here is because of the inference that I am trying to screw someone. First of all, the only people that have been screwed so far are Nick and myself. At the very worst, I am only proposing doing unto you what we have done unto ourselves.

I have provided a series of links for other crate engines and their respective costs. The point is that performance engines are not cheap. I am not trying to make a direct comparison of costs or value. The Ford and the Chevy engines are mass produced domestic engines. The LS7 probably bears the greatest similarity to out 4-liter engine, titanium rods and stuff. It retails for over $19,000. Remember it is still a push rod power plant that is made in some volume.


LS7 engine link:

http://www.crateenginedepot.com/store/LS7-Crate-Engine-Small-Block-17802397-Coming-Fall-of-2005-P930C0.aspx

5.0 liter Ford performance crate motor link:

http://www.seanhylandmotorsport.com/frppcrate/modularcobra.shtml

300 ZX engine – Stage 4 link;

http://www.z1motorsports.com/product_info.php?cPath=1_6_342&products_id=58


Thanks

Mark Lewis

 

Now this opens up a whole new can of worms..... This could get VERY interesting. I am not talking about scratching balls either....

 

Mark Pdx, I thought it was porshce owners that had the small penis'.

Nick, no offense intended, I am intrigued with the project, just cant see the market. Had some questions to ask.

Paul S, up yours.

 

Let me see if I get this right, the consensus is that I am a jerk, with limited functioning gray matter who is boring and stroking a Ferrari which is a projection of my own physical limitations…Strange, my wife has come to the same conclusion.

Mark Lewis

 

brilliant - i think my wife feels the same - that's what her lawyer tells me.

 

......now why did you have to go and tell me that? I knew the 348 heads would fit but I didn't know the 355s would too......hmmm, I sure could use another 100 hp or so

 

On the topic of oil consumption on 308's vs cylinder wall distortion I disagree- surprised?
When I rebuilt my own 308 engine I tossed the 4 ring piston in favour of a 3 ring design with low tension rings made to my specifications. So technically I should have even worse oil control and increased blow-by. I dont, in fact between oil changes of around 3000-4000kms I have no change in oil level as indicated by the dip stick. The modern vavle guide seals I installed are to thank for that, not measuing my cylinder walls with lasers and using every technique known to man to make sure they are dead straight. I understand the importance of a straight cylinder wall but the distortion "all" 308's have is being overstated and isnt the cause of oil consumption. Its the top end.

 

Its also interesting that so many (Not just Nick, but many around the country) go against the 308 service manual, which states " It is adviseable to replace the liners. Only in the case of imperative reasons is it adviseable to grind. When effecting this operation, cylinder liner should be removed from engine block."

 

Your point is taken.

In this vain, the oil return passages in the head and block can be enlarged during a rebuild. We have debated whether or not to tune the volume of oil flowing top of the head by restricting the oil passages. Standing oil can work its way down the valve guides into the combustion chambers…not a good thing. Anybody who as disassembled a 308 knows the engine is an awful black mess.

Valve seals also play a critical role. The increased oil control maybe largely attributed to using a positive valve seals such as Viton. Here is a link to a discussion regarding the various types of valve seals on the market.

http://www.automotiverebuilder.com/ar/ar79842.htm

It is strange that Ferrari has any problems with valve guides because the valves are direct acting. There should be little or no lateral load on the guide…there is no rocker arm. Nick tells me that he has even seen worn guides on 355’s and other Ferrari V8’s. The 3.5 and 4.1 liter engines have had their valve guide replaced with premium quality pieces.

Block distortion:

We have observed that the factory method of rebuilding a short block will result in sleeve deflection. Every time a nut is tightened on a stud the block deflects. As previously mentioned even bolting up the bell housing will distort cylinders number 4 and 5 about .001 of an inch. Because the top of the sleeves protrude above the deck there is a point load around each sleeve that is greater than that of the deck. We believe that we have remedied this problem.

Ferrari’s solution is use three compression rings which was not the norm even 25 years ago. This allowed them to simplify the manufacturing process. The decks did not have to be flat with the sleeves installed. Sleeves could be prepped for installation without the expense and time required to bore and hone with a torque plate. This option was further complicated because the deck and the sleeves were not flush.

Our solution is to install the sleeves and mill the deck flat. We use MSL head gaskets which demand a perfectly flat surface to mate with. Then a torque plate is used to simulate the deflection that the sleeve will see when the engine is completely assembled. Either the bell housing needs to be installed or an addition torque plate need to be installed to duplicate the loads associated with bolting the transmission up. Then sleeves can be bored. Some machine shops don’t use a cutting oil when the sleeves are bored. The result is excessive heat which causes the sleeves to distort. The cutting oil helps to maintain a constant temperature. The sleeves are then honed and plateau honed. The only step that is not employed to get a concentric sleeve is to heat the build during machining operations. This is typically reserved from ultra high end racing motors.

Notice the picture on Nick’s website. http://www.nicksforzaferrari.com/forzaferrariwebsite1_065.htm. All of the flange area at the top of the block is used to support the sleeves. This requires two different sleeve designs for each block, one for the inner sleeves and another design for the outside sleeves. This results in a deck that is perfectly true with no voids. Ferrari uses only one flange design and has voids at the ends of the block. The outside sleeves are supported by less flange area. The sleeves are then basically glued in place with a special compound, around the flange and where block received the sleeves at the bottom of the sleeves. This is proven technology. Steve uses method on Vipers, LS1’s, and various other performance engines. The end result is a concentric bore that is very stable. We think that this provides for a better sealing surface. We are hopeful to limit blow by and enhance oil control.

A low tension oil ring was mentioned in a recent post. One of the primary benefits of a low tension oil ring is the reduction of friction. We have taken that one step further. We have gone from 3 compression rings to 2. The top compression ring is reduced to about .8 mm in width. The ring material is now steel which is far more durable. The rings are coated to reduce friction and to decrease wear. The typical compression rings has a coefficient of friction of about .7 to .8; our rings have a coefficient of between .1 and .2. This results in a measurable increase in horsepower of 1.5 percent in other applications. Just as important is that the coated steel rings should seal better for a longer period of time.

The piston shirts are also coated to reduce both friction and scuffing. We identified areas that generate unwanted friction and have sought ways to reduce it. The two biggest culprits are the rings and the valve train. Both of these have been addressed.

We use custom pistons. There are many reasons. Our piston package is lighter than stock. It gives us an opportunity to spec the clearance between the head and the piston at TDC to maximize combustion efficiency. The gasket thickness is also taken into consideration. The stock piston sets down in its bore at TDC as previously documented by others at this website. This lowers compression and results in a less complete combustion burn. We have also relocated the top ring closer to the top of the piston.

We are also using forged pistons with expansion characteristics that provide for reasonably tight clearances. They are not a full on racing piston. It is not as tight as stock but it should not be too noisy when cold. Heck, with Nick’s exhaust, I would be surprised if you will be able to hear himself think much less hear piston slap.

We have spec’d ring land and ring finishes that are extremely flat to aid in ring seal. Check out this link: http://www.totalseal.com/. Cleaning and reusing stock pistons can result in a less than optimum ring land finish.

The bottom line is that our methodology is directly applicable to any rebuild not just the 4-liter.

Mark Lewis

 

Mark, I would like to see you guys hot hone one of these blocks just to find out how much they move in addition to the torque plates. I'm sure you've seen this link: http://circletrack.com/techarticles/82438/

As for the valve guides on the 355s, I remember a poster saying that he saw at the factory a station where valve guides were pounded in by a worker wielding a hammer. Does not sound like precision manufacturing to me. No wonder the concentricity sucked. I'm sure a precision machine shop using a Serdi type machine could do much better than the factory specs.

 

I had assumed the block distorts when the flywheel and clutch housing bolt up, as when the heads are torqued, or when anything on the motor is tightened, as our service manual wants the heads torqued up to measure alignment of the main journals. That being the case, what about heat? If the block is distorting so much when its cold, whats it going to do when its heated? In discussing this block distortion, have you actually observed liner distortion, or just the block? It has been my understanding that the liner, being of a fairly heavy mass of hard ductile iron, would resist distortion within the block via torque or thermal stress, by "floating". That the liner would remain a fairly rigid tube, while the lighter softer block distorted around it. I would make the argument, that no matter how the liners were bored, that the motor is going to continuously move around. That even if you could measure the liner straightness with the engine fully assembled, expansion and contraction would continue altering it.

Its been questioned, that the metal thats been removed in the liner bores of the block could weaken the overall structure. I recall some discussions with Norwood, being that many 308 blocks had been seen with looseness between the main bearing cap and the block, in the web area of the block that is cut down for the main cap to settle into. If that has been happening on stock engines with downgraded power, has this been taken into consideration with higher power output combined with this critical metal removal? I am not sure, but understood the F-40 had a four bolt main cap? Is that something that could be applied?

Not only Ferrari, but Alfa, Maserati, Renault, Peugeot, Citroen, Volvo, every engine I have ever found with wet iron liners in an alloy block, has a specification for liner protrusion above the block deck by several thou., which I have been aware was to compensate for the expansion of the two dissimular metals at differing rates, so that at full temp the deck height would be approximately flat. That the aluminum walls of the block would expand with heat, higher than the height of the installed liner. Are you saying Ferrari miscalculated this, or that the new gasket takes that into consideration in some way?

 

The workshop manual specifically shows that the liners should protrude above the block head. Page B45 and B46
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I too would be interested to see what running temps would do to a block like this. If I am reading that site correctly, are they saying as high as a .052" increase in bore size over cold in some areas? It is interesting how variable it was from one area of a cylinder to another. Seems it would be difficult to get a decent cold running clearance, and equally amazing that iron block engines, which I assume would all be simular to this hot measurement result, can run anywhere near the mileages they achieve. My guess would be that the wet liner would be more evenly expanded, keeping the cylinder a truer tube.

I admit being shocked seeing a machinest drive a guide into an aircraft cylinder head with a drift and a hammer, seems crazy to do on a $5k engine part. But those old guys explained that by using your hands, you can "feel" the guide fit in its bore and know if it will hold or not. Nothing worse than to have a guide slip at 10,000 feet over the Pacific Ocean, or in the 14th hour at Daytona. As long as it was reamed for size and the seat ground on an arbor guide rod installed in the now reamed guide, it should work quite well.

 

This is a great discussion. Thanks.

In conversations with Steve, he dismissed the idea that the sleeve protrusion was necessary so that the deck would end up flat at operating temperatures. Yes, an alloy block and a ductile iron sleeve do expand at different rates. However it is also true that sleeves are exposed to substantially more heat than the Block. In short the protrusion of the sleeves does not expand flat at operating temperatures.

It is my opinion that the justification for a sleeve protrusion is based on the stock head gaskets that are used and the manufacturing efficiency. Our method is more labor intensive and requires more machining processes.

If the sleeve did not protrude and actual were allowed to recede below the deck at any time during engine operation, then gasket failure would result. The fact that Steve’s system is working on bunch of different types of alloy blocks would tend to support his contention that two metals stay flat at operating temperatures despite different rates of expansion. One of his blocks is a 1,000 hp Viper motor.

It needs to be remembered that MSL gasket have not been around for a long time and are only now available for the 308. MSL gaskets don’t work if the deck is not perfectly flat. Given the widespread use of MSL gaskets on alloy engines, I believe that this issue has been resolved.

The sleeve is physically trapped between the flange of the deck and cylinder head. It can move, but it isn’t floating. Steve uses an anaerobic sealant to adhere the sleeve to the flange. The sealant is also used on the lower portion of the sleeve as well.

The block is machined to establish very accurate centerlines for each cylinder. The sleeve is not an interference fit. Initially, the lower portion of the sleeve was a few thousands larger than its bore, it was chilled and pressed into place. This resulted in a number of cracked blocks of various types. That should demonstrate some characteristics of expansion between the two metals and how the sleeve actually expands more because it get hotter.

Steve and I have discussed heating the block during honing. It requires a heated reservoir of machining fluid and a torque plate with coolant passages to circulate the fluid in and out of the block. It is more dangerous and uncomfortable because the block gets up to around 200 degrees. It is more expensive. It is used on racing engines. The question is if it is cost effective on a street engine. Steve didn’t think so at the time.

Mark Lewis

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There is another thing that I failed to mention in the last post. Our blocks and sleeves have been cryogenically treated. I know there are some you that think that this is snake oil, but the process has a positive impact on thermal expansion. The metal matrix of a part is altered by cryogenics. After a metal object has been cryo’d it expands and contracts more uniformly.

An example of this is the new cryogenically treated rotors. They are guaranteed for the life of the car. Yes, most of the attention on these rotors is focused on the wear resistance of the rotor, but more important to this discuss is the fact that these rotors don’t warp. I suppose I could find a link or two, if there is interest.

Also, Steve stress relieves green castings to provide a more stable foundation for his machine work.

On the topic of valve seals, the outside diameter of the valve guide where it receives a valve seal must be concentric to a couple of thousandths. If it out of round then the seal will deform and leak. Proper installation is important. I wish now that I had measured this area during disassembly to determine what the factory tolerances were.


Mark Lewis

 

What are these "MSL" gaskets you refer to?

I know Multi-layered Steel (MLS) gaskets have been around for at least 25 years in production engines so they can't be this "new" wonder technology that you refer to, can they?

 

The following links may prove helpful in understanding MSL head gaskets.

http://www.federal-mogul.com/vgn/images/portal/cit_776/12950726MLS%20Brochure.pdf

http://www.aa1car.com/library/2004/eb80440.htm

http://www.4secondsflat.com/Cometic-MLS_Gaskets.html

http://www.4secondsflat.com/Cometic-MLS_Gaskets.html

http://www.4secondsflat.com/Cometic-MLS_Gaskets.html


Mark Lewis

 

Sean,

Thanks for posting the block cross-section.

The cross section reveals that the rigid portion of the aluminum block is at the lower seal of the liner, about midway between the top and bottom of the liner. The upper section of the block is relatively flexible, in an axial direction, due to its geometry. When the head is torqued down, the sleeve and the aluminum will be compressed, as will the head gasket.. The portion of the head gasket in contact with the sleeve will be compressed more so that the portion in contact with the surface of the aluminum block. This is appropriate as the combustion pressure will be larger than oil pressure passing between the block and the head. What is not shown in the drawing is where the studs thread into the block.

At temperature, the liner, studs, block, and head will all expand at a ratio of about 13 to 8 (ratio of α’s), aluminum verses steel, depending on the specific alloys. This means the aluminum block and head will expand more than the steel liners and retaining studs. So, as the engine gets hotter, the clamping force on the head and sleeves will increase. This is a fortunate and desirable outcome.

The next important assumption is that the studs will maintain tension on the sleeves as the engines heats up, assuming the sleeve length, from the lower seal to the surface of the head, is the same as the stud length, from its upper thread in contact with the block, to the contact area at the top of the head washer. The ratio of these two lengths will determine how much clamping force remains on the sleeve top surface as the engine heats up. The aluminum, to a large degree, given its geometry, will go along for the ride. The temperature of the sleeve and the block will not be too different. This is because the cylinder and block are both cooled by coolant circulation. There will be a bit of a temperature gradient between the inner wall of the sleeve and the outer wall, resulting in the average sleeve temperature being somewhat higher than the aluminum block. Also, the block will reject some heat to the surrounding air, but this is likely small, compared to heat rejected to the coolant. If the studs are longer than the sleeve portion in compression, that from the lower seal to the head surface, some head clamping tension will be lost at temperature. If the studs are shorter than the sleeve, unlikely, then the clamping force on the sleeves will be somewhat more at temperature.

I am unsure what cryogenic treatment means. In my metalogy class, we were taught that material characteristics depended on holding elevated temperatures for a defined period of time and then cooling the specimen at a particular rate or quench method. If this condition is not met, then it’s likely there is no benefit from cryogenic treatment. Steel, cooled from temperature at a high rate, will produce marthensite. But this requires holding a specific temperature for a period of time before rapid cooling. Martensite yields hardness and increases yield strength if the alloy is hardenable not all alloys of steel are hardenable. So, I guess that if sleeves that are subjected to cryogenic cooling after they have achieved room temperature, then there is likely no change in the metallic matrix due to the cryogenic treatiment. On the other hand, if the sleeves are subjected to cryogenic cooling from a pre specified hot condition, then a large percentage of martensite, relative to austenite, will be created, resulting in a very hard and strong material.

 

As long as heads studs have been mentioned, we have replaced all of the stock head studs with 190,000 psi custom pieces that Steve has spec’d. We ordered ten sets of studs. A picture of the studs was previously posted.

As far as the temperature difference between the block and the sleeves, it is Steve’s contention that the sleeves get much hotter. This is the result of his testing and experience. Intuitively, it makes sense that things are hotter the closer that get to the heat source.

The cost to cryogenically treat an engine is between $500 to $1,000 depending on the number and size of the parts. I have seen brake rotor treatments quoted from about $25.00 on up. Here is some interesting reading about cryogenics.


http://www.bso.uiuc.edu/~chillar/CryogenicTreatmentofMetals.pdf

http://www.metal-wear.com/racing.htm

http://lennon.pub.csufresno.edu/~rlk16/cryo.html

http://www.nwcryo.com/motorsports.html

http://www.motorcycledaily.com/04july01cryogenics.html



Mark Lewis

 

So any power numbers yet?

 

Of course the liner is hotter. It's in the middle of the combustion process. What is the temperature of combustion in a typical IC engine?

 

Usually, water temps are measured at the head and/or radiator.

Where in the motor are you asking for temps? Depends on materials (rate of disapation), compression ratio, masses of components involved, octane exhaust valve size/lift/duration.... tons of variables.

 

Sure, but the short answer is about 2000F