So my car has been down a year now, it is no longer my daily driver (obviously), and I DO plan on rebuilding as a 427 Dart LT1 after they become available. However, I just bought a house, and I feel as though it may be a while before I get everything I need/want to do a proper engine build. SO, I was thinking in the mean time of getting a lower mileage used LT1 to put in to get it back on the road and enjoy the car again, allowing me to build up a 427 at my own pace and not feel the rush to get the car going again and cut corners on the build.

If I put in a used LT1, I figure I might as well put in a custom cam before putting the engine in the car, keeping revs under 6500 to keep the motor alive. I will NOT be doing a rebuild, as this will be a budget motor to get the car back on the road, and have some fun enjoying the car again. Other than a cam, rockers, springs, etc., I will also be installing my Canton RR pan and Melling 10% HV pump with GM 'white' HP oil spring for added bearing insurance, might also put in Impala head gasket, and mill stock heads to bump up compression some as well, since I will be running strictly E85, and have a wideband for tuning to optimal A/F ratio. My questions are as follows:

1) Should I replace the cam bearings (all or just front?) before putting it in, or should I just swap the cam out? b) If so, can this be done relatively inexpensively? Again, cost is a factor, and am not doing an engine rebuild.

2) What RPM's should I try to keep the car under to keep it living on the stock short block with a new cam, under 6500?

3) What tests should/can I do to the engine before putting it in the car? Leak down, compression, oil pressure, etc? If the engine is in need of a rebuild, I do not want to use it.

4) What would be a ballpark RWHP for a stock bottom end, cam-only, stock head, M6, peaking <6500 RPM, on gasoline? Is 350 rwhp possible? (I know I will be running higher CR and E85 which will add a few hp, but I just want to get a ballpark based on other's cam-only builds). On my old stock 170k mile engine, I dynoed 322/338 on stock cam with E85, boltons, maxxed out injectors, and mild ported heads (less than LE1 porting).

5) Any other suggestions?

I just want to get my car back on the road and enjoy it again, cruising, autox, local test/tune drag, instead of just letting it sit for another 2 years until I can build my "big" engine. It doesn't have to be "daily driver" reliable, but I also don't want the engine to go out or spin a bearing within a few months (or less) of me installing it either. Sorry for the long post, I just wanted to get some good advice on this. Thanks!

 

Hi kgkern01
I have a 96 Z28 SS with 17,000 miles. I am thinking of putting in a Golans 396and have thought about selling the stock motor complete. the only thing done is 52mm TB, TB bypass and chassis dyno tune, 276rwhp/300ftlbs. The under hood is like new as it has rarely seen rain.
Thanks
brad

 

2 more questions.
Can the cam bearings be replaced without tearing down the whole bottom end?

How far can the stock heads be milled down for max compression (running E85), and would anything be gained from going larger on the valves and valve job while the heads are off for milling? I would be happy with even 15rwhp from the higher CR and valves alone if possible.

Again this is a budget build stock bottom end build (w/cam)

 

1) I would replace all bearings.
2) keep it as low as you can. But the higher you go the more power you will make.
3) i would do all 3 tests, you may find that you dont want to do the swap.

I blew my stock shortblock with boltons and mild headwork. Spinin the motor to 6200rpms.

 

Is that easily and cheaply done, just replacing all (cam, rod, main) bearings?

 

Yeah I will definitely do a leakdown and compression and oil pressure tests first to make sure I have a good base to work with. How much would I be looking at to just have all the bearings replaced (cam, rod, main)?

 

Well I figured that I would be in for about a grand total, especially considering about $350 for a custom cam, but I do want to keep the costs as low as possible while still having a somewhat reliable engine. I know after a cam swap a lot of people spin bearings, and I was wanting mainly to prevent that from happening, so would the high pressure oil pump spring, in new 10%HV Melling pump and Canton RR pan (which I already have both) along with new cam bearings and RPM under 6500 be enough to prevent spinning bearings after a cam, or would I have to replace main and rod bearings too to prevent that?