This past month I've received many letters regarding E85 (ethanol). Ethanol is similar to the grain alcohol you may have spiked the punch with back in college. In its E85 form, it's a 15-percent-gasoline/85-percent-ethanol blend that can be made from many renewable resources, such as corn, sugar cane, wood chips, corn husks, and other agricultural waste. Unlike gasoline, it reduces carbon emissions by more than 80 percent, while eliminating sulfur dioxide emissions, which lead to acid rain. Currently GM, Ford, and Chrysler have over 5 million flex-fuel vehicles on the road, and the Department of Energy predicts that ethanol could put a 30-percent dent in America's gasoline consumption by 2030!
If you haven't already noticed, GM has a big push on right now, "Go Yellow." If your vehicle has a yellow gas cap, it's a flex-fuel vehicle that can run on both gasoline and E85. Remarkably, the ECU can sense the ethanol content in the fuel being used and change the calibration to accommodate it. Unfortunately, ethanol (or alcohol) has a much lower BTU content than gasoline, so you'll consume more, getting less mileage, than running on petrol. However, for us hot-rodders; ethanol has an octane rating of 105! Wow! At 105 octane you could raise the static compression to squeeze that ethanol to extrapolate greater heat out of the fuel. You could build a smaller engine to consume less volume of fuel. Between the smaller engine and squeezing it harder to get more power, maybe we could have our cake and eat it too. Will these engines be flex-fuel? No, but they claim that the infrastructure is going into place to make E85 readily available across the country, and the price is coming down. Just think, we won't be considered those pesky hot-rodders who don't care about the environment with our clean-burning, powerful engines. What a concept!
To find out if your vehicle can run E85, or to locate E85 stations near you, go to e85fuel.com.
Weenie RoastQI recently had an engine built for my street-driven '63 Chevy Impala SS. My problem is that I'm getting spit-back through the carbs during initial take-off, usually around 1,000 to 1,500 rpm. Eighty percent of the time the spit-back is black smoke, the other 20 percent there are flames. I have rejetted the carbs until my spark plugs burn a light chocolate-tan, reset the intake manifold twice with new gaskets (I don't think it is a vacuum leak with 5 inches of vacuum at idle at 750 rpm), compression-tested each cylinder (showing 132-136 psi across all eight cylinders), and have the timing set at 10 degrees initial with a total of 34 degrees at 3,000 rpm.
Here are my engine specs: '79 350 four-bolt 0.030 over, 10.1:1 Lunati pistons, standard crank, Lunati 00013 solid cam with 256/270 degrees duration at 0.050-inch lift, and max lift of 0.500/0.515 inch. I have Lunati 1.5 roller rockers lashed to 0.028 inch at operating temper-ature. The heads are stock steel with 2.02/1.60-inch valves. I'm also running a Weiand Tunnel Ram mani-fold, Hedman headers, and two Holley four-barrels (0-9776 450 cfm with mechanical secondaries, 0.062-inch jets, and 6.5 power valves). I'm also using an ACCEL electronic distributor with a matching coil.
All of the above parts are new, the carbs are rebuilds from JEG's, and I'm utilizing a B&M 3,000-stall torque converter. The trans is a TH350 with 3.73:1 gears in the rear, running on 93-octane Exxon pump fuel. Any thoughts?George MunasWheeling, WV
A Let's see if we can get you past that early lean backfire. First of all, that is quite a camshaft you're trying to run on the street! Also, your Weiand Tunnel Ram is a race-only drag piece. Years ago a few manu-facturers produced what they called street tunnel rams. They had reduced the runner sizes to better suit street rpm ranges. You're going to have a real tough time transitioning from idle to full power with your package. What the engine is looking for is a nice shot of fuel to wet the walls of that tunnel ram and get enough fuel to the cylinders before the air gets there. That is where your lean backfire is coming from. Also, your very low 5 inches of idle vacuum is getting a weak signal back to the carburetors. The idle circuit works OK because you have two carbs, and the idle feeds are below the throttle blades. When you open the throttle, the signal must activate the main circuit. This delay between the idle circuit, the accelerator pumps, and the main circuit is the lean bog. You may be able to tune around some of the lean transition by reducing the main circuit air bleeds. These air-bleed restrictors are located in the venturi area above the booster. The idle air bleed is located toward the outboard side of the carb, and the main air bleed is toward the inboard side of the carb. If you have some fine stainless steel wire, you can insert it into these air bleeds and see if it improves your drivability. With the reduced air bleed, the main circuit will come in sooner.
Also, you may want to look at the accelerator pump cams. You may be able to tune the squirters to get the fuel in on the early part of the throttle opening. Your 4160-model carbs are somewhat unique in that they are mechanical secondaries, but are only a single-pump accelerator system. Your carbs should have 0.031-inch accelerator squirters. That is quite a large squirter, but you can swap out the accelerator pump cam for a more aggressive one; this will help get you past the transition. Holley offers the Accelerator Pump Cam Assortment Kit (PN 10-12) with eight different ramp profiles to help tailor when you want to squirt the fuel. The only downside is that you'll need two kits. Next you need to swap out your power valves to a lower vacuum level. With only 5 inches of idle vacuum, you will want to go to a 3.5-inch valve. The rule of thumb is that you want your power valves tuned to 2 inches below the idle vacuum of the engine. The power valves are sold under PN 125-35.
To help your idle vacuum, you can increase the idle spark advance. We would recurve your ACCEL distributor to limit the mechanical advance. We like your 34 degrees total, but we'd like to see around 16 to 18 degrees at idle.
If all else fails you could swap out your very aggressive camshaft to a tamer one. But with the tuning advice listed above-and a little patience-you'll get there.
May Pops!QI recently installed a 410ci small-block in my '97 two-wheel-drive truck. It was built with decent parts and I ran it on a rear-wheel dyno, making 367 hp. What does that translate to on an engine dyno? One other thing, the rear-wheel diameter is 29 inches with a 3.70:1 gearset. The dyno techs ran the engine up to 6,800 rpm in High gear (it's built for that or more), which translates to over 150 mph wheel speed. The tires are rated for a max of 112 mph. I asked about this deal before they ran it, but they said they know about it and had never had a wheel blow on the dyno! Of course you know the weight of the truck is actually increased by the tie-downs. Why didn't they blow?Bowtie LaVigneVia e-mail
A Boy, you guys are lucky. Yes, your tires are speed-rated for a reason, but I wouldn't be too worried about the tires. For short bursts at relatively low temperatures, and at full-inflated pressures, the tires can withstand quite a bit. What I would have been worried about is the driveshaft coming out from under your truck! Trucks are especially bad because of the length of the driveshaft. Driveshafts reach what is called the critical speed, based on length, diameter, and material. Once the driveshaft reaches this point it begins to flex and whip out of round, and you're at the point of no return. The driveshaft pulls out of the transmission and whips around the bottom of your truck-and everyone's legs standing around the truck! You guys were lucky.
Drivetrain losses will vary from vehicle to vehicle. Automatic transmissions and torque converters eat more power than manual transmissions. Hypoid-geared rearends eat more power than their front-wheel-drive counterparts. Anytime you change direction you eat power. I've seen losses as low as 14 percent on a SF-840 Superflow chassis dyno. I've also seen it as high as 25 percent! For most testing I use a standard 18-percent loss. I'm going to assume that you have a 11/42-ton truck with an 8.5-inch corporate 10-bolt rearend, based on your 29-inch-tall tires and 3.70:1 gears. I would say you're in the 18-20 percent range. If you add 20 percent to your chassis dyno numbers you come up with 440 hp. That isn't a bad number for an engine installed in the truck with full exhaust and accessories. Most engine dynos don't have true street exhaust or engine accessories on them. Many shops will even run electric water pumps to get the highest engine dyno numbers. The only time you will find an electric water pump on my engine dyno is on a drag race engine. Just food for thought.
Vortec BoogieQI just picked up a '98 454 Vortec truck engine. Please break down how to get maximum 91-octane power in a carbureted, mostly bracket-racing, 3,400-pound non-smog application. To save money, can I use a non-roller cam? How much horsepower is the block and crank good for? What are the flow numbers for the heads? If I decide to go to a blow-through supercharger system, are these heads good for low detonation? Are the fasteners reuseable? ThanksJim FrascheVia e-mail
A The Vortec 454 came out in '96 and is a great building block for any street-performance buildup. The cylinder heads on that engine family feature the large oval port that is very similar to the late-'60s oval. The exhaust port is much better than its earlier counterpart, and the combustion chamber is a 105cc refined kidney-shaped design. The chamber promotes good mixture motion and reduced spark require-ment. As long as you keep the engine fed with the proper amount of fuel, keep it cool, and don't overspark-advance the thing, you should have no problem with detonation control. The stock castings have an intake valve size of 2.07 inches and an exhaust valve of 1.72 inches. The intake port has a volume of 235 cc. The heads flow 230 cfm at 0.400 inch. Peak flow at 0.600-inch lift on the inlet is 268 cfm, with 186 cfm on the exhaust. These numbers were generated on my SF600 Superflow bench, without an exhaust tube.
To use a standard flat-tappet camshaft, you will need to pick up a Gen V cam gear, PN 10106429. This cam gear has the larger flat-tappet bolt circle. You will also need to leave out the factory roller camshaft thrust plate. Any Mark IV cam-shaft will work in this engine. Do note that you'll need to replace the pushrods to match the shorter flat-tappet lifters. With all these valvetrain mods, be sure to machine the cylinder heads for 71/416-inch screw-in studs for the rockers. The factory Gen VI design is a net-lash system, where the lifter preload is preset by the factory stack-up. The cylinder heads have the proper rocker pedestal height, but they are only tapped out to 31/48 NC thread. While we're talking about fasteners, all the fasteners in the Gen VI engine are reusable, which is very nice compared to some of the late-model engines.
How much power can the factory '98 short-block handle? If you can keep the engine out of knock, and don't spin it over 6,500 rpm, you should easily build 500 to 550 hp. The pistons, on the other hand, may be the first thing that I would think to replace. With most of the late castings thinner than their earlier brothers, I also wouldn't bore the engine beyond 0.030-inch over. However, you should be able to have many years of fun if you keep your head about you.
Hard StarterQI recently bought an '86 Chevy 4x4 with a 350 and TPI induction off of an '86 Firebird. The installation looks bad, with the harness spliced in from the donor and the mechanical fuel pump still hanging there. My problem is that it doesn't start right up. It takes about four to five seconds to fire. I have done a complete tune-up and was told that this type of start time was normal. Also, it idles rough from time to time. My mpg is currently at 12 and I think it should be around 15. I have the TPI swappers book and it states that if you have a weak alternator it can wreak havoc on a fuel-injected engine. What else should I check? I was told it has an RV cam, but also that it should be OK with the MAF setup.Dennis MartinMemphis, TN
A A crank time of four to five seconds isn't normal. Yes, system voltage is critical. A standard operating voltage of 13.8 to 14.2 is a nice range for the system to work with. While the computer has voltage compensation built into the software to adjust for lower or higher numbers, the EFI will run fine. Still, you should shoot for these numbers.
We would look to your fuel pressure for your hard-starting problem. You need to check if you have residual fuel pressure with the engine off. There is a check valve built into EFI fuel pumps to hold residual pressure for the next engine start-up. Also, the fuel pump should cycle when you turn the key to the run position for around three seconds to prime the fuel system. Install a fuel-pressure test gauge to the fuel rail of the EFI. If the system doesn't retain a pressure in the high-30-psi range, the fuel pump is the problem. With your TPI system being a swap, it's tough to say which pump they used. All the in-tank pumps used for your model of truck were TBI pumps that put out a max pressure of 18 psi. For a good universal inline EFI pump, check out ACCEL universal fuel pump, PN 74701, which produces 200 lb/hr fuel flow at 45 psi, supporting up to 400 hp. This is a perfect size pump for your application.
As you said, a small RV camshaft will work fine with an MAF sensor-controlled EFI system. As with any heavy 4x4 truck, it takes quite a bit to getter rolling. I would agree that you should be able to knock down 15 mpg out on the highway, although I doubt you will see that type of mileage around town. Work out your fuel pressure issue and clean up your connections from that badly spliced harness and you will have better reliability. Good luck with your truck and enjoy.
Stat SelectionQI recently put a new aluminum radiator in my '70 SS 454 Chevelle and was wondering if the choice of thermostat temperatures would make a difference in the car's performance. The choices are, of course, 160, 180, and 195 degrees. I put a 195-degree stat in the car and want to know if this will help or hurt the overall performance, or does it not really matter? Thanks.Bart PinsonVia e-mail
A The thermostat selection in some engines doesn't really matter because the engine operates above that temper-ature all the time. The only time the stat comes into play is during start-up and the period before the cooling system controls the engine temperature. Many big-block Chevelles couldn't run at 160 degrees if their lives depended on it. When you're running down the freeway at 70 mph and it's 50 degrees outside, maybe the cooling system could pull the temp down that low. But that would be rare.
Your Chevelle came with a 180-degree stat from the factory. We didn't see the 195-degree stats until years later with the advent of smog controls. Yes, the engine will have less wear running at a higher temperature, and the engine oil will run cleaner because you burn out the condensation better, but unless the whole package is designed to run at a higher temp, you will see lower performance at a higher operating temperature. With a cast-iron-headed big-block, the higher temperature will lower your knock sensi-tivity. The engine will heat the incoming charge of fuel and air more, decreasing performance. The hotter the charge temp, it's easier to pre-ignite, which isn't a pretty place to be. You will have one cylinder that likes to knock first, creating much higher combustion temperatures, setting off a vicious cycle.
We would drop in a 180 stat and enjoy the days when the temps are lower. Drag racers will bring their engines to the line in the 100-140 temp range to extract the last amount of performance out of those engines. For every 10 degrees of inlet air temp increase, you lose around 1 percent of horsepower. Combine that with the fact that the hotter the engine runs, the less spark advance the engine will tolerate; they run them cool. If they came to the line at, let's say, 190 degrees, I would doubt they would make it a quarter-mile before the engine expired!
TPI BoogieQI have a question on the TPI system on an '87 Camaro with the L98 350. I was thinking of putting in a ZZ383 425hp crate engine from GM; however, I read that the runners choke off the air to the engine around 4,000 rpm. So what can I do to make this work? For example, putting larger runners or larger injectors, or is this TPI system not the right way to go? I really want this car to be a 5-second performer from 0 to 60. Thank you.Kent TatarinVia e-mail
A The original TPI system used from '84 through '92 did exactly what GM wanted it to do, give you gobs of torque and plant you in the seat! And it did, while knocking down some very impressive fuel economy numbers for its day. The horse-power wars had not fully set in back then, and based on the theory that torque moves the car, they had a killer system. As the horsepower wars set in, the engine speeds needed to go up. To support the power bogies the marketing department required, along came the LT1 engine design with its short-runner manifold. Is the TPI a good design for performance? It certainly can be with the correct match of components, and running the engine speed where it gives you the most benefit. There is one company that probably has more time in developing the TPI systems for performance use than anyone else. Myron Cottrell at TPI Specialties married himself to the TPI systems back in 1984 when the Corvette came out with the system. He raced them, won with them, and developed a full line of components to support their performance use.
Yes, in stock form on a 350-cid engine, the TPI intake system will fall off in power over 4,000 rpm. Add 33 more cubic inches to the engine with high-flowing cylinder heads and a performance cam-shaft and that airflow wall comes into play earlier in the rpm range. You can either upgrade your TPI with large-tube runners (PN 500-503), a big mouth base (PN 500-509), a 52mm throttle-body (stock is 48mm), and a modified mass airflow sensor to move the air required for your 383, or step into one of TPI Specialties' Mini Ram manifolds (PN 500-530). The Mini Ram looks very much like a GM LT1 inlet manifold, and some say it's a copy of an LT1; however, Cottrell released the Mini Ram a full year before the LT1 engine was released. The bottom line is that TPI Specialties can support you with all the components and calibration necessary to drop the ZZ383/425 into your '87 Camaro.Source: tpis.com
Clutch PlayQI'm having a hard time finding a budget-minded adapter/bellhousing to fit an LT1 ('96 Camaro SS) T-56 transmission to my push-style clutch setup in my '79 Monte Carlo. I'm aware that these transmissions will only handle 450 lb-ft of torque and are not as good as a D&D or Keisler retrofit. I'm married to a limited budget so that's not an option. I've found kits that cost $500-$600 and was wondering if you guys had any resources that incorporated the adapter plate and bearing retainer (if that is all I need) to bolt the T-56 to the engine? The rest of the swap I've got handled (crossmember, clutch linkage, driveshaft, speedo). This poor gearhead would welcome any ideas of directions for further research.Thanks.Tadd BainumVia e-mail
A It's a shame with all the T-56s out in fourth-gen Camaros that it's such a pain to get them into our earlier cars. Yes, there are some pricey kits out there to accomplish what you are trying to do.
If we were like you, on a budget, we would leave the trans and bellhousing complete and use the '96 LT1 clutch setup with the hydraulic clutch. We know you have linkage-style clutch actuation, but you could change it over to hydraulic without a lot of pain (cash). Check with Keisler Engineering for its hydraulic clutch conversion for the G-body cars. You really don't need the complete kit if you go with the factory bellhousing slave cylinder. Keisler's system comes complete with a nickel-plated steel master cylinder designed for high-heat performance car use. The bracket to mount the master to the firewall, the linkage to the pedal, and a remote reservoir come in the kit.Source: keislerauto.com
Camshaft RetentionQI bought a Gen I short-block and just installed a cam (from Comp Cams). Is something supposed to hold the cam in place? What holds it in there? Did I miss something? I installed the cam and lubed it with the supplied lube. However, my build did not go as scheduled and it's been sitting on a stand for months. Do I have to relube it? I can see that the red cam lube has run down the sides of my block. If so, what should I use? Also, I'm going to use a one-piece Milodon rubber oil pan gasket with metal sleeves to prevent over-tightening. Does it need gasket sealer? Thanks in advance.Derrick SakaiSan Leandro, CA
A Camshaft retention on Chevrolet flat-tappet camshafts is achieved by grinding a slight amount of taper (angle) into the camshaft lobes. The spring pressure of the valvetrain, combined with this angle, forces the camshaft rearward into the block. Also, the load of the engine oil pump helps pull back on the camshaft. No, you didn't miss anything on your installation.
Yes, you will need to relube the engine, but we would do it by priming the engine well. If you don't have an engine oil primer you will need to get one. This primer allows you to spin the oil pump with an electric drill motor. GM sells a very nice primer under PN 12368084 that will work with all V-6s, small-, and big-block engines. Next, pick up a can of GM Engine Oil Supplement. New environmentally friendly engine oils out there mean a reduced amount of additives for sliding contact (like lifters). With all engines running roller tappets, they have reduced the amount of zinc they put in the oil. A pint of EOS can be purchased under PN 992869. A trick that we've heard of lately from the camshaft manu-facturers is to run diesel-spec engine oil for break-in. They have a much greater additive package, but you wouldn't want to run it full-time. Chevron Delo 400 Multigrade is readily available from many auto parts stores or your local Chevron dealer. Whichever way you decide to go, prime the engine with an electric drill for several minutes, and then turn the crank 90 degrees. Continue priming the engine and turning the crank 90 degrees until you have made one full revolution. This will ensure that you have lubed all rod bearings and filled each of the hydraulic lifters. When you fire the engine, follow Comp Cams' recommendation for their camshaft break-in.
Finally, the one-piece oil pan gaskets that GM designed and used on the one-piece rear main seal blocks work great. The aftermarket has tooled up and produced the same design to fit the earlier two-piece seal blocks. The Milodon gasket is made from silicone rubber and, as you state, has sleeves to prevent overtightening. We would recommend using a high-quality silicone sealer at the corners only. This is what GM does on the later engines, with great success.
Bottom-Of-Page CamQI am currently building an '81 Malibu. I've put together a 355 with flat-tops, a full Eagle forged rotating assembly, and a Comp Cams Xtreme Energy cam XE294H. It also has a set of Brodix 2.02/1.60-inch-valve aluminum heads that are angle-milled to bump the compression to 11.2:1. On the induction side I have a 650-cfm Holley double pumper, an Edelbrock Air Gap intake, and an ACCEL Billitech distributor. What kind of horsepower and tourque is this combination going to make? Also, what stall speed would you recommend? Comp calls for a 2,800- to 3,200-stall converter. I currently have a 10-bolt posi with 3.73:1 gears and plan on running 275/60R15 M/T ET Street drag radials. The rear lower control larms are getting boxed, along with a rear sway bar, air-bags, and a 10-point cage. Is a trans-brake overkill or a good idea? This car is intended for the street but will spend most of its time at the track. Sorry for all the questions, but I had a lot on my mind!Justin EssmanGrantville, KS
A couple of years ago we joked around about building a "bottom of the page" engine, looking up our application in a manufactuer's catalog and choosing the part off the bottom of the page. In other words, the biggest, baddest, most outrageous parts they had for our specific engine. Well, you've hit the bottom of the page with your Xtreme Energy camshaft. That, along with a dual-plane intake and a 650-cfm carb, isn't going to cut it.
The Xtreme Energy XE294H is a great camshaft, its specs coming in at 250/256 degrees duration at 0.050-inch lift, 0.519/0.523 inch max lift, and ground on 110 centers. This with a single-plane racing inlet manifold and a good-flowing set of heads will make around 450 hp with your compression. You said you're going to run a set of Brodix aluminum cylinder heads-a great line of products, but you didn't state which head you have. In the 23-degree stock valve-angle head they have more than 10 to choose from, from the smallest inlet port of 180cc, going all the way up to 227cc. All their current cylinder heads start at a 2.08-inch inlet valve. Your heads have 2.02-inch inlet vales. Brodix offered a street head years ago with a 2.02-inch valve and a smaller inlet port. I'm concerned that you have these heads.
If you wish to stick with your short-block combination I would recommend going with a 195-210cc Brodix HV1000. As for a carburetor, you will need at least a 750-cfm carb. It will make slightly more power with an 850, but you will give up some street manners. This package should produce around 450 hp at 6,500-plus rpm, and around 430 lb-ft of torque in the high-4,000 rpm range.
Now, converters, gears, and trans-missions. You will need a fairly loose 10-inch converter. This engine will need around a 3,800-4,200 stall speed to get into its torque curve. As for a transbrake, it matters how much money you have to spend on a converter. With transbrakes, you abuse the converter holding it at full power with the transmission locked. The converter would need to be upgraded with anti-ballooning plates, fully furnace-brazed fins, and an upgraded sprag. Standard 10-inch converters aren't that expensive; however, expect to pony up $500 more for a transbrake model. All the transbrake-equipped transmissions I'm familiar with require a manual-shift valvebody. This can be quite an inconve-nience for street driving, although you did say the car will be a mostly track car.
One last thing: The factory 7.5-inch-ring gear 10-bolt that came in your Malibu will not stand up to a transbrake and will probably die behind the aforementioned small-block. You'll need to upgrade to an 8.5-inch rearend from GM or Buick, or a Hurst Olds Cutlass. Or swap in the old standby 12-bolt Chevy rearend. Have fun with your bracket Malibu. This package should break ino the high 11s with some tuning and a good chassis. It's the perfect engine to run on pump gas and save you a few bucks. Start conservative on your tuning and you'll be surprised at how well it may run.
Water BabyQI have had an incident of hydraulic locking in my small-block engine. After the initial failure to rotate, I took out the plugs and expelled the water. The engine now runs, but unevenly and with a pronounced tick rather than a knock. I am reluctant to take the engine out as this is not an easy job. I am hoping this could be a valve gear-related problem, since the compression is OK on all cylinders. Not having had the engine out before, how can I tell if the lifters are hydraulic or mechanical? Any suggestions would be most welcome.Dick McCallVia e-mail
A Isn't it amazing how fast an engine will stop when it ingests water? Hopefully, the engine wasn't running and your poor Chevy wasn't caught in a flood of some type and filled up with water.
You say the engine runs unevenly but you have even compression in all eight cylinders. A hydraulic lock can do a great deal of damage before you know it. You can crack pistons, bend rods, crack cylinder walls or heads, blow head gaskets, or bend valves or pushrods. Maybe you got lucky and a valve was trying to open at the same time the piston was trying to compress the water in the cylinder. This would be unbelievable timing.
To check for hydraulic tappets I would remove the valve covers and see if all the cylinders have valve lash. Any mechanical camshaft requires valve lash to work properly. This lash could range from 0.012 inch all the way up to the 0.030-inch range. If you pull the covers and the valves have no lash, it is pretty safe to say it is a hydraulic camshaft. Another way to make sure is to bleed down a lifter. First, make sure you have the cylinder you're testing at top dead center. Then slowly turn the adjusting nut on one valve a quarter-turn at a time, letting the tappet rest for about a minute between each quarter-turn. After you have turned the adjusting nut around two turns down, back off the nut the two turns you have preloaded the lifter. You should pick up a good deal of lash from bleeding the oil out of the lifter. You must take your time to allow the oil to escape from the tappet. Good luck, and I hope you find a simple solution. CHP