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Can you ID a cam?

Either way I needed to pull the motor to fix other things like my oil pan and the front seal on the transmission. Now I'm really trying to start over and make sure that everything is done right and matches my exact application and needs. I'm done trusting that local shops really know what I'm looking for and how to get it :)
 
Step one:

put a timing tape on your balancer while engine is out!
 
Ok I finally got the specs on the camshaft that was in my 454. The shop oopsed and initially gave me the wrong info.
Intake : 204 .268 .455 Exhaust 208 .270 .459. So I guess that's pretty small. I'm still trying to figure out the best camshaft for a 1,400 to 5,400 range to maximize torque and low to midrange power. Thoughts and opinions would be great :)
 
Ok I finally got the specs on the camshaft that was in my 454. The shop oopsed and initially gave me the wrong info.
Intake : 204 .268 .455 Exhaust 208 .270 .459. With a lobe spacing of 116. So I guess that's pretty small. I'm still trying to figure out the best camshaft for a 1,400 to 5,400 range to maximize torque and low to midrange power. Thoughts and opinions would be great :)
 
781 heads are very good OEM castings. no issues there. call comp and get them to spec one out for you. degree the cam in when you install it. then have it tuned correctly after start up. I'm willing to bet something was off in the carb set up or distributor set up. cause it sounds very stock, for cam and pistons. I would guess you are in the 9.0:1 compression ratio range. if all else is stock.
 
DEMON44 said:
781 heads are very good OEM castings. no issues there. call comp and get them to spec one out for you. degree the cam in when you install it. then have it tuned correctly after start up. I'm willing to bet something was off in the carb set up or distributor set up. cause it sounds very stock, for cam and pistons. I would guess you are in the 9.0:1 compression ratio range. if all else is stock.
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Yeah I have heard good things about these heads. I will call Comp next week and get there input. I know I can research this but I'm curious I have been told to degree the cam multiple times I'm not sure how or what exactly I need to do
 
I had to have my 406 sbc reworked in June. I went from a comp 270 magnum 224/224 at 50 and 470 lift hydraulic flat tapped with roller tipped rockers to a comp 264hr which is around 212/218 at 50 and 495 lift. The compression ratio is close to what it was. Now it's at 10.2:1 and the aluminum heads were ported when the 270 cam was used, so they are the same. The rockers are now full roller.

The duration dropped and lift increased. The heads had too much porting for the 270 cam as well. The engine builder wanted more velocity on the air/fuel charge. The engine now has more low end torque and still halls balls on the top end. The roller setup seems to rev up much faster too.

The roller cam gives more performance with less duration. It seems to work well for an engine built for low end torque. The most important thing is to match all the parts. This time around I had the engine blue printed to help with performance and longevity and the builder carefully considered all the parts we had to use. He did talk to comp camps about the proper cam for my build. Mine has to pass smog, so they had to stay small on the cam. The builder likes a bigger cam and can make a ton of torque with it, but he said it would never pass smog, so it was not an option for me.

I have found that many people may be recommended for a build and may seem to do great work, but I have been disappointed a number of times. Everyone has their own way of doing things, but they don't all work that well. My head guy was used to full blow race motors and worked on NASCAR parts as well, but went a bit overboard for the street. Same thing happened with a carb I had done.

Changing a part here or there, willy nilly, won't get you the most bang for the buck. I was happy to have a pro build my engine. Hopefully the third time is a charm (first one went well over 100k, but lost a head gasket).
 
Yeah that's why I am doing a ton of research and why I tore everything apart. I want everything to match as close as they can. It's funny but I have actually visited 3 of what I have been told to be the best machine shops in my area and talked with there BBC "experts" and had countless calls and emails with summit and been pulling opinions from the experienced people on here over the last few weeks. I'm trying to gather all the information I can before putting any parts in my motor. The last thing I want to do is replicate the mediocre setup I currently have or make something worse. Don't get me wrong I love projects but don't feel like pulling my engine over and over .
 
Ok guys I bit the bullet and did the full on disassemble. Turns out I had flat topped pistons and they are 40 over. I gave in and purchased some domed top pistons a way nicer cam and springs. (And of course all the other goodies you replace while in there.) All said and done everything will match and this whale should have the power I'm looking for. This spring when I have the money I still plan on changing the gearing then this k5 should be really fun to drive :)
 
Did you ever figure out what compression ratio you had, or what your new ratio will be? I am surprised to see that you need domed pistons, but I am also used to reading about small blocks. The cam looks like it should do well, if the listed power band is correct. I don't know if small block and big block cam specs can be compared. Based on cubic inches and the fact that is is a flat tappet cam, the duration should give nice low end torque but still be able to get up there a bit in RPM, without falling on it's face.

Make sure that you run a good additive to your oil, such as ZDDPlus. That flat tappet cam will need the zinc. Or, run a race oil with the zinc in it. Even with my full roller engine, I still use half a bottle for good insurance. For the non roller cam, I used a full bottle to 5 quarts of oil.
 
CGT80 said:
Did you ever figure out what compression ratio you had, or what your new ratio will be? I am surprised to see that you need domed pistons, but I am also used to reading about small blocks. The cam looks like it should do well, if the listed power band is correct. I don't know if small block and big block cam specs can be compared. Based on cubic inches and the fact that is is a flat tappet cam, the duration should give nice low end torque but still be able to get up there a bit in RPM, without falling on it's face.

Make sure that you run a good additive to your oil, such as ZDDPlus. That flat tappet cam will need the zinc. Or, run a race oil with the zinc in it. Even with my full roller engine, I still use half a bottle for good insurance. For the non roller cam, I used a full bottle to 5 quarts of oil.
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I never did run the numbers on this motor. I do however know that my gen 454 is a lower compression motor. And once I pulled the heads off and saw the odd choice of pistons I decided to upgrade and match my pistons, cam and intake to ensure this all works well together.

Attached is a picture of the flat topped pistons it had in it. Honestly I'm clueless when it comes to figuring out specs to determine ratio.

uploadfromtaptalk1388888954449.jpg
 
I have heard that compression ratio plays a decent part in choosing a cam. I seem to recall that the bigger cams need more compression. Your cam isn't huge, and you are increasing compression with the new pistons, so it will probably do OK. I would be most worried about getting the compression too high and having detonation issues.

Is it possible to find a friend who can double check your setup, or maybe even a shop to verify what CR you will have? I don't recall if you are doing all the work yourself or having an engine builder work on it. Do you have to do any machine work to the block? Are you reusing the crank and main bearings?

You have the right intent with matching parts, just don't rush things and do something you may regret.
 
It's still worth checking but I'm pretty sure the comp will be around 9.5.
 
CGT80 said:
I have heard that compression ratio plays a decent part in choosing a cam. I seem to recall that the bigger cams need more compression. Your cam isn't huge, and you are increasing compression with the new pistons, so it will probably do OK. I would be most worried about getting the compression too high and having detonation issues.

Is it possible to find a friend who can double check your setup, or maybe even a shop to verify what CR you will have? I don't recall if you are doing all the work yourself or having an engine builder work on it. Do you have to do any machine work to the block? Are you reusing the crank and main bearings?

You have the right intent with matching parts, just don't rush things and do something you may


I'm doing the work myself but a machine shop helped me figure out the parts and ordered everything for me. he said it will be a 9.5 to 1 he said it could be a little tiny bit higher but 9.5 is what he's expecting
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It sounds like you will be safe. I wouldn't expect the same amount of load on an engine in a K5 that an engine in a 3/4 ton pickup would see when the pickup is loaded or pulling heavy........well unless you use the K5 like a 3/4 ton pickup.

I got away with running a lot of advance on my last 406, while it was not fully loaded and the weather was cool. Hot weather and/or a load really let me know that it was too high for that CR. I ended up having a bad distributor shaft and my actual centrifugal advance was way faster than what the charts showed. After I fixed that, the truck ran better and could handle the harder conditions.

I think the torque of the big block and the lower weight or load of a K5 will make it less likely to even want to detonate.

Oh, how I would love to have been able to have big blocks in my pickup and K5. If you're going to have a gas guzzling v8, it might as well be a big V8. I am stuck with smog, so an engine can only be built so much before you make it unable to pass. I am already getting up there in power level for a naturally aspirated small block as it is. The big block has even more potential.
 
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