Dwigley Posted January 21, 2012 Share Posted January 21, 2012 I had been planning on running an F54/N42 head build but after extensive reading on this forum I have decided to stick to a low compression build. I have a bone stock flat top F54 and an uncut P90 head that I'm going to run with SU's. I have a Schneider 274F cam that I was going to put in the N42 head. My question is should I, or can I, run that cam with a 8.7:1 motor? What is the largest cam that you can reasonably run with a low compression motor? Quote Link to comment Share on other sites More sharing options...
BluDestiny Posted January 21, 2012 Share Posted January 21, 2012 That's the stage 2 the am from MSA correct? I've seen it run in a pretty much stock 280zx. He said it livened it up. He was using stock efi though not carbs. You can run it, but what are your desired goals? You might put it in and find out it just isn't cutting it and then you'll have wasted your money. Quote Link to comment Share on other sites More sharing options...
madkaw Posted January 21, 2012 Share Posted January 21, 2012 I run that cam with my p30-e88 combo running 9.55 compression. I run 38 degrees advance. Not sure if that helps answer your question. I would do the math to have a combo that gets atleast 9+ CR. Not sure of your concern of using the 42 head That cam is a bit wimpy, you might consider bigger Quote Link to comment Share on other sites More sharing options...
Dwigley Posted January 21, 2012 Author Share Posted January 21, 2012 I'm looking to build a spirited N/A motor that will be a weekend warrior and run some Solo II. If we can clean the N42 up without cutting it and run a Nissan head gasket it should be somewhere around 9.8:1. We have 93 super unleaded with 10% Ethanol but from what I'm reading that will not be enough to run a full 36 degrees. Especially in the summer here in Texas. I was just curious as to what results people have had running a 270 or 280 degree cam on 8.5:1 compression. Quote Link to comment Share on other sites More sharing options...
BluDestiny Posted January 21, 2012 Share Posted January 21, 2012 Go with a tad higher comp and a bigger cam. I would trim the P90 down since it has a better quench zone and run a bigger cam. I was running the stage 4 msa cam with an f54 flattop with an e88. And that car was most definitely fun. Did have to turn the timing back Quote Link to comment Share on other sites More sharing options...
Gollum Posted January 24, 2012 Share Posted January 24, 2012 If you're trying to keep a low budget on it, then it sounds like you know what to do. Run what you have, the cam + P90 + carbs. It wouldn't cost much to do the typical .080 P90 shave and install the shorter valves, but it can be very time consuming, or pricey for the gain if you're having a shop do 100% of the work. But will it run fine with what you have? Yes. How much power will it make? Depends way more on a million things other than compression. Yes compression matters a great deal, but chamber prep, port work, intake arrangement, carb tune, etc all matter just as much in the grand scheme of things. If you need a number though, I'd say 175whp is totally achievable by most people with that head, cam, and compression combo if everything else is done well. Some might get more, but many others get less, simply because they overlook details and just throw money into their project instead of research and patience. Quote Link to comment Share on other sites More sharing options...
Lazeum Posted January 24, 2012 Share Posted January 24, 2012 For what is worth, I was running F54, flat top, N42 and the cam you have, it was pinging & I had to retard timing by many degrees to make it work. It was not optimized but it was fun to drive anyhow. Quote Link to comment Share on other sites More sharing options...
Dwigley Posted January 26, 2012 Author Share Posted January 26, 2012 Lazeum, Thanks for your reply. I think the smart thing to do is stick with the low compression build for now and see how that cam runs. The N42/N42 combo that I pulled out would not pull RPM worth a flip. When I started to pull the motor apart I found the head to be one of the JDM non-efi heads that TonyD often talks about and the ports on that thing are UGLY! The P90 may not build any more power but with the 274F cam, it should pull more RPM. I'll save the uncut N42 block and start gathering parts for a 3.1L and then send the P90 to Braap to have him do his magic hopefully like he did on yours. That thing is a piece of ART! Quote Link to comment Share on other sites More sharing options...
Lazeum Posted January 26, 2012 Share Posted January 26, 2012 Notice that Braap did not only did my head, he was also in contact with Rebello who did a cam that matches my setup. This is the important part of the process. My combo is a matching assembly so port work, valve sizes, valve lift, spring, cam profile, etc. everything goes together for a purpose. Quote Link to comment Share on other sites More sharing options...
Gollum Posted January 26, 2012 Share Posted January 26, 2012 Notice that Braap did not only did my head, he was also in contact with Rebello who did a cam that matches my setup. This is the important part of the process. My combo is a matching assembly so port work, valve sizes, valve lift, spring, cam profile, etc. everything goes together for a purpose. We need comments like that in a sticky all by itself somewhere.... Quote Link to comment Share on other sites More sharing options...
Lazeum Posted January 26, 2012 Share Posted January 26, 2012 (edited) I agree but if you spend enough time reading posts on the board, the idea pops out here and there everytime! I forgot to add also the comp ratio in my list of matching parameters, which is not crazy at all (head milled by 1mm) Edited January 26, 2012 by Lazeum Quote Link to comment Share on other sites More sharing options...
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