April 2010 Performance Q&A

Tom Truty Jan 27, 2010 0 Comment(s)

After that, if you want to take your skills to the next level, check out its Racing Engine Building School online. Reher-Morrison brings you right into its engine building facility and teaches you the ins and outs of professional racing engine building, with small class sizes and one-on-one instruction. Let us know when you're going-maybe we can get a combo deal!

Source: rehermorrison.com

Synthetic Leak
Q: I have a 305 bored 0.060-inch over with an Edelbrock carb and manifold, large-valve heads, 9.5:1 pistons, and FlowTech headers. My problem is a persistent oil leak in the front of the engine. I used oil dye and UV light to find this leak. To date, I have twice replaced the oil pan gasket-once with a four-piece with sealant and once using a one-piece with sealant. Also, I have replaced the timing cover gasket, a new Chevy timing cover, and a crank seal.

Still the leak is there. I have also checked to ensure I haven't left any bolts out of the front of the engine for accessories. I recall an article you wrote in CHP concerning synthetic oil and leaking. Can you shed any light on this problem? Thanks for helping me in my slippery situation!

Bob Kay
Via email

A: Keeping synthetic oil in the pan has always been a challenge. If there is any chance of a leak, this slippery stuff will find a path.

We've been using a four-piece pan gasket forever. When Fel-Pro released the one-piece silicone pan gasket for the early small-blocks we tried one on the engine dyno. It had a few slight seeps that would creep up over time. When we built the engine for our Stock Wagon we used a one-piece gasket so when NHRA asked us to tear it down for tech inspection, the pan would be easy to drop and replace. It has had some type of leak on every rebuild. On the last rebuild, we decided we had used the gasket too many times and that's why it was leaking. Installing a brand-new one-piece gasket, and making sure everything was straight and true, it still has a very slight seep from the front of the pan. Next time we're going back to the trusty four-piece gasket.

As for your situation, you've replaced everything on the front of the engine. The only thing you haven't mentioned is whether the leak is coming from the pan seal or the front crankshaft seal. You should have been able to see the leak path with the UV lamp. You replaced the front cover seal, but you didn't mention the condition of the sealing surface of the damper. If the damper is worn from years of service, the front seal won't have a chance. You could replace the damper or go with an easy fix: Fel-Pro's Harmonic Balancer Repair Sleeve repair kit. This is a very thin steel sleeve that presses over the damper sealing area, which gives you a fresh sealing area. These kits are very inexpensive and have saved many a damper. Pick one up for a small-block under PN 16202 if you need to tune up your damper.

One last thought, you said you replaced your front cover. The groove in the front cover that the oil pan gasket seals into is welded to the front cover. If this weld isn't perfect, there could be a slight seep between this groove and the front cover. This would be asking the pan gasket to seal on the front face of the gasket, not in the proper plane in compression from the pan. This is a long shot, especially since you have replaced the front cover and had a leak with both.

Hope talking through your problem has given you a couple of ideas. There is nothing worse than pulling into your buddy's driveway with your car and leaving a calling card. Not to mention what it does to the underside of your Camaro. Good luck sealing up your small-block.

Source: federal-mogul.com


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