67 L36 Rebuild

[Lawrence S.]

Hi Guys,

I have searched the archives and found the camshaft I want to use for my build it is the Sealed Power CS 1093M from Napa. The direct replacement for the OEM camshaft. I also read to use Keith Black 360 pistons, but when I search for those I don't find a vendor that has them for GM cars. I looked at Summit and also at Jegs. Is there a sealed power piston you would recommend so I can get everything from Napa?

Thanks for the help.

Lawrence

[Bob H.]

Re: 67 L36 Rebuild

I'll be interested to hear the comments from those knowledgeable. I was told by my engine builder that many pistons were made off shore and not to use them. He used USA made Wiseco forged pistons during the rebuild of my 427/435 that is bored .030. I went along with his recommendation. I believe they were purchased through Summit

[Duke W.]

Re: 67 L36 Rebuild

Google Keith Black pistons and you will find the United Machining Web site. They manufacture the pistons and have a complete online catalog.

Jegs, Summit,... are just retailers.

When looking for parts it's always best to go to the manufacturer's Web site for the part number and techincal data, then shop by price from retailers.

Do the same with Sealed Power pistons and you should find the Federal Mogul online catalog.

Duke

[Joe R.]

Re: 67 L36 Rebuild

Lawrence,

My engine has been bored 30 over and has Speed Pro (Sealed Power / Federal Mogul) pistons. Is your engine standard bore or what?

Joe

[Joe L.]

Re: 67 L36 Rebuild

Hi Guys,

I have searched the archives and found the camshaft I want to use for my build it is the Sealed Power CS 1093M from Napa. The direct replacement for the OEM camshaft. I also read to use Keith Black 360 pistons, but when I search for those I don't find a vendor that has them for GM cars. I looked at Summit and also at Jegs. Is there a sealed power piston you would recommend so I can get everything from Napa?



Thanks for the help.

Lawrence

Lawrence------

For your application I would recommend a Keith Black KB 176 piston, assuming you want to maintain near original compression ratio. This is a hypereutectic cast piston and is much stronger than the original conventional cast pistons used for your application. This piston is available in +0.030" and +0.060" oversize. You should be able to get these from Summit, Jegs and maybe even NAPA.

I don't think that Federal-Mogul/Speed-Pro/Sealed Power makes a piston for your application which is hypereutectic cast and will produce near-original compression ratio. I could be wrong, though.

[Lawrence S.]

Re: 67 L36 Rebuild

Standard Bore

[Lawrence S.]

Re: 67 L36 Rebuild

Google Keith Black pistons and you will find the United Machining Web site. They manufacture the pistons and have a complete online catalog.

Jegs, Summit,... are just retailers.

When looking for parts it's always best to go to the manufacturer's Web site for the part number and techincal data, then shop by price from retailers.

Do the same with Sealed Power pistons and you should find the Federal Mogul online catalog.

Duke

Thanks Duke

[Lawrence S.]

Re: 67 L36 Rebuild

Joe,

I thought you like the Keith Black 360 pistons because of the CR and did not like the 176 because of the higher CR? I swore I read that last night in the archives? Could be wrong though.

[Joe L.]

Re: 67 L36 Rebuild

Joe,

I thought you like the Keith Black 360 pistons because of the CR and did not like the 176 because of the higher CR? I swore I read that last night in the archives? Could be wrong though.

Lawrence-----


You definitely did read that. Personally, I would not build a big block with 10.25:1 compression ratio. I only recommended the KB 176 because I assume that you want to maintain the original compression ratio. Lots of folks on this board think that lowering compression ratio is "sacrilegious" and causes the engine to "sound different". I disagree.

My recommendation to you would actually be to use the KB 360 pistons, providing that you are willing to lower the compression ratio. Depending on factors like deck height, final combustion chamber volume, and head gasket thickness, you should end up with a compression ratio of between 9.0 and 9.5:1. That's what I recommend for a street big block. Yes, I know that there are folks here that say that they have original 11.0:1 big blocks and they run fine on today's pump gas. I do not want to chance it, though. I remember well the days when I had a big block that had constant detonation problems and it was MISERABLE. I NEVER want to deal with that again. And, if you build the engine to original compression ratio and you do have detonation problems, what are you going to do? Tear the engine down and lower the compression? Reducing ignition advance will not always satisfactorily solve the problem.

Here's a clue: current GM crate big block engines with cast iron heads all have compression ratios of 8.75:1 AND recommend 92 octane fuel. Don't you suppose that if GM engineers felt that these engines could operate well on higher compression ratios that they would build them that way? It wouldn't cost another dime to raise compression ratio and they could probably achieve somewhat higher horsepower output.

[Lawrence S.]

Re: 67 L36 Rebuild

Thanks Joe I thought I read that right.

Right now I am guessing the engine is stock based on several factors. I am able to buy 93 octane 100% gas no ethanol from a station in my neighborhood. The car runs very well on this fuel with detonation at times...not sure why it is only on occasion but clearly not all the time. In any case, I don't want ANY detonation so building the engine around 9.5 CR seems like it makes sense to me.

Thanks for the help

Lawrence

[Joe L.]

Re: 67 L36 Rebuild

Thanks Joe I thought I read that right.

Right now I am guessing the engine is stock based on several factors. I am able to buy 93 octane 100% gas no ethanol from a station in my neighborhood. The car runs very well on this fuel with detonation at times...not sure why it is only on occasion but clearly not all the time. In any case, I don't want ANY detonation so building the engine around 9.5 CR seems like it makes sense to me.

Thanks for the help

Lawrence

Lawrence------


The other thing to keep in mind is that you may not always have the fuel you currently have available. For example, you could drive on a road trip to another area which does not have that fuel available. The best plan is to have an engine set-up for the least stringent fuel requirement. That way you can drive anywhere you wish and have no concerns about fuel. That's how I like it. Having to rely on octane boosters, racing gas, avgas, etc. is for the birds. I want to be FREE of all that nonsense.

[Lawrence S.]

Re: 67 L36 Rebuild

Lawrence,

My engine has been bored 30 over and has Speed Pro (Sealed Power / Federal Mogul) pistons. Is your engine standard bore or what?

Joe

What pistons did you use? Forged or Hypereutectic?

[Lawrence S.]

Re: 67 L36 Rebuild

If anyone has used the KB 176 pistons on a 67 L36 rebuild I would like to know what results you had regarding detonation, and what CR you ended up with using these pistons. Also if you know what head gasket thickness you ended up using that would be helpful too.

[Joe R.]

Re: 67 L36 Rebuild

What pistons did you use? Forged or Hypereutectic?

Lawrence,

The pistons that are installed in my block right now are part number L2268F. My machinist picked them, I don't know anything about them. I would recommend doing more research than I did. It appears that you are. I don't know if they are right for your application, my engine is a L72.

Joe

[Joe L.]

Re: 67 L36 Rebuild

Lawrence,

The pistons that are installed in my block right now are part number L2268F. My machinist picked them, I don't know anything about them. I would recommend doing more research than I did. It appears that you are. I don't know if they are right for your application, my engine is a L72.

Joe

Joe and Lawrence------

The L2268F are Federal-Mogul/Speed-Pro forged pistons for SHP 427's (L-72, L-71) and are 0.030" over. They will produce a compression ratio of ABOUT 11:1.

I do not recommend the above for an L-36 (in fact, I don't even recommend them for an L-72 or L-71 but that's another story). The L-36 originally used conventional cast pistons. Today's hypereutectic cast pistons replace the old style conventional cast. They're nearly as stong as forged but they retain all the other benefits of a cast piston (e.g. tighter piston-to-bore fit, lower wear, lower noise).