1980 Cutlass w/455 Race project

rocketattack

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Oct 1, 2020
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I am looking at assembling a 455 for drag race only. I have had a few 455s built for me over the years. My last endeavor though was not a happy one for me. The short story is it blew up after the 4th pass! not gonna go into details about that has its been over 10 years now. I think my temper has cooled down and I no longer speak to or about that builder. I digress though, sorry back to my current dilemma.
I am trying to attempt to get 12:1 compression. Why you may ask? My answer is why not? If 11.5:1 is acheivable why not a bit more at 12:1? This will not be a pump gas engine, HIGH octane only. I have done a lot of calculation and have come up with the following. My block is bored at 4.156 basically .030 over. An Olds Eagle crankshaft at 4.5" stroke (this crankshaft uses a 2.2 journal requiring the use of BBC rods) using BCC Eagle rods at 6.660" connected to Icon pistons w/ 1.75 compression height and +14.4cc volume. This will put the top of the piston 0.035" out of the bore. The head gasket will be 4.200 dia. and 0.040 thick. The heads are stock Edelbrocks. Have never been cut down and are still 77cc chambers. The parts list is long and expensive as it is Oldsmobile. I am sure I will need a girdle for this. I know where to get it and the cost of it. I just do not want to write it down. (the wife is looking..lol) I am looking at getting the following parts. I also recognize the pin size differences between the rod and piston. To solve this the rod will be re-bushed to fit the pin. My biggest concern is what rod bearing to use? I like the time tested Clevites and have always used the "H" series but I have been to Clevites site and see they have a better series, the "V". Their catalog states it is close to the Vandervell bearing design. I am sure it will be for a BCC but can not find anything for the rod I am using. I may be confused on the dimensions that I need to know and use to select the correct bearing. Thoughts or concerns?

Head gasket -- Cometic/CGT-C5809-027
Crankshaft---- Eagle/ESP-104554500
Rod------------Eagle/ESP-66603D2000
Piston----------Icon/UEM-IC886KTD-030
 

Olds 307 and 403

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Oct 4, 2018
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Melville, Saskatchewan
Wow, .005" clearance between the piston and head, that is living on the edge. Sucks that you had a bad experience with a builder and it blew up.
 

rocketattack

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Oct 1, 2020
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LOL.... I guess a clearance of 0.005" is not good? I'm not sure where I should be on piston to head clearance. This is one of my issues. I'm not sure where to find information for this spec. I haven't bought parts yet. Still doing my research. as the saying goes measure twice cut once. Research, research and research some more then get a list of the parts and research some more then order parts.
 

Olds 307 and 403

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Oct 4, 2018
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Melville, Saskatchewan
I would bet money, something on the bottom end went south. The factory had .045" to .050". I believe most builders suggest .035" minimum due to expansion.
 

rocketattack

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Oct 1, 2020
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well let me see. Piston rods 3&4 with 5&6 decided to separate or bend in the middle. The pistons were flat tops but now they have imprints of the valves in them with a lot of holes and cracks. 1 piston is missing. There are very large chunks of aluminum in whats left of the oil pan. I would guess there wasn't enough clearance.
0.035" Min? I'm going to go 0.040" min then to be safe.
 
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