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Advice for fellow TR owners from Tom Shea Racing
Home phone until 9 pm 952-892-5669
Cell phone anytime (612)-209-9090.
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Tom's Stage II Engine Freshening
I recently had my engine freshened at a local shop. They specialize in small block Chevys for circle and dirt track racing. I have had them do several engines for me in the past, satisfactorily. I should state that the focus of a shop like this is providing a competitive Chevy V-8 for racing at a good price.
The problem with a “good price” is that there has to be compromises to achieve that. There is no free lunch. When going through an engine for freshening, all parts are considered and the range of tolerance tends to be a gray area biased towards budget in this case.
What might be OK for a budget race engine is not necessarily good enough for a high end build like we want for our turbo V-6 engines in our street & show cars.
As part of this freshening (2nd build), my heads were inspected and had a couple of guides replaced. There were new seals and a valve job using the existing valves.
I should state that I have had this engine in this car for years prior, with very little use due to various excuses. I did play with it from time to time but few and far between. I was never happy with how the thing ran. It was very high strung and hard to control on the street. It had a pretty big cam (276) and a fairly high compression ratio (9.5/1) for a street motor.
The engine was built years ago (previous build), using a solid roller cam but with hydraulic roller lifters. At the time roller cams were very expensive, and I thought I could make this (race) cam work on the street doing this. The higher compression ratio was to match the cam, and I thought I could make this work as well.
I resolved to try to tinker with this car a little more in recent years and resigned myself to the fact that changes had to be made. I wanted a more street friendly engine, and there were other problems that I would need to check upon disassembly and inspection. It was running poorly, especially at higher RPM, I thought possible valve springs, although I had not put much running time on it.
Upon inspection of the hydraulic lifters used with the (previous build) solid roller, I found all of the pushrod cups to be frozen in place, like a solid lifter. This is after years of sitting and only occasional running. Needless to say it was not running very well like that. When I first got this motor running years ago (first build), it was very soft at low RPM. It took to over 4K to come alive and then it would rev to around 7K almost instantly. Traction challenged! It wanted more, but the lifters weren’t up to the task. I’m sure my abuse is what caused the lifters to fail, along with using hydraulic lifters on the solid cam profile application.
I decided to change to a milder cam and lower compression ratio. After consulting with Red Armstrong and Rich Lasseter, I settled on the Comp Cams, hydraulic roller (269). That doesn’t sound much smaller but it is a hydraulic grind. I had previously determined that 8.5/1 would be my new compression ratio.
When I assembled the engine (2nd build) at my shop I noticed that the oil drain holes in the ends of the heads did not match very well with the holes in the gaskets. The passages in the block were not aligned well with the gaskets either. The gaskets were Fel-Pro 1007 Lock wire. I also noticed the floor of the oil passage in the block was shallow just under the gasket. I remember thinking that there was a possible concern there, but I didn’t address the issue since I have observed this before and not had subsequent problems.
After assembling and installing the engine, I noticed it would smoke a little at idle. I checked the turbo and intake gasket seal, both good. I addressed the possibility that it was partially fuel even though the smoke looked blue. The A/F ratio was OK. I checked the cylinder pressure with both cranking compression and leak-down tests, both showed no problem. The spark plugs were fouled.
The way the smoke would occur was not completely consistent with valve guide seals, since it would not always puff smoke at initial start. The smoking would start after a short time running. I assumed the oil level was building up to a higher level in the valve covers, covering the tops of the guides. These engines, like most, sit at a slight rear downward angle in the car. I assumed the oil was not draining fast enough at the rear drain hole and therefore was also using the front drain hole and or the pushrod holes as well.
I tried to run the engine with the driver side valve cover off and a fabbed up oil catch chute in place instead. The oil level rapidly rose to overflow the lower valve cover rail of the head. The oil drain holes are above the level of the lower valve cover rail. Since the chute was not sealed to the head, I had to shut it down and clean up a mess. I considered making an open top valve cover for this observation, but the M&A head valve covers are not overly abundant or inexpensive. I decided it didn’t matter since the engine was coming back out anyways.
Upon disassembly and inspection, the combustion chambers were oil fouled and one of the new Teflon seals was off of the newly installed guide top.
I was pretty sure the oil drain back was the problem, but couldn’t rule out the heads being less than perfect. I didn’t want to just address the oil drain without having the heads thoroughly gone through to make sure they were “as good as it gets”.
The gaskets for the heads and intake alone for this project are close to $150.00, not to mention the hassle of R&R of the engine. Additional consideration for me was the 4L80E transmission is a tight fit and needs to be dropped to get the bell housing bolts out of the top adaptor plate holes. I just removed it since it’s difficult enough to get the engines in with HR engine mounts, with a 2004R in place, let alone a 4L80E.
I brought the heads to Head Werks. A shop highly recommended to me by a trusted friend and fellow TR guy, John at Master Transmission. This was not cheap but I was not about to leave any stones unturned now, after having to pull the engine again after having just put it back in.
Steve at Head Werks warned me that it would be expensive, and asked me to consider replacing them. I wanted to keep those heads even though it turned out that they didn’t flow nearly as well as I thought they would. Steve pressure checked them and found a small coolant leak which he repaired, along with all new guides and valves. I would recommend this place if you want top shelf, but be prepared to pay for it.
I called Mike Laciura at Wildcat engines in Adel GA. I asked him about the oil drain issue. He stated that the procedure he uses for his engines includes removing .180 to .220 from the block internal corners area at the oil drain path. He also opens up the gasket to allow full flow. Wildcat can be contacted through the GSCA. I had a stage motor done by him and Abe our webmaster had his 109 engine done there. I did the R&R on that motor, so I have seen a couple of his engines first hand. I have nothing but good to say about Mike and Wildcat performance Engines. I have called Mike for tech from time to time and he is always polite, courteous and helpful.
I followed Mike Laciura’s advice on the oil drain relief prior to reassembling the engine and installing it. When I ran it, I did not see oil smoke at idle, but there was some condensation due to the cold weather that might have masked it a little. I’ll have a much better look after the weather warms to cooperate.
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