2.1 long rod cam choices

Engine, Transmission and related drivetrain.
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dan_the_man2
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2.1 long rod cam choices

Post by dan_the_man2 »

I'm looking to get feed back from those of you running this combo. I am interested in a street engine, but the reading i've done shows cams with a lift around 530 or in that range. I did not see any cam suggestions Jason Grey write up. So your suggestions would be great. Also I am interested in compression ratios. Sounds like 9.5 to 1 seams to be as high as is advised. Is this due to the pistons being used? Z22e and vg30 piston tops look to be dished or cut for 4 valve. Is this making the chamber more prone to detonation? Sorry if this is routine and old covered data. I've looked with out great results.
datzenmike
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Re: 2.1 long rod cam choices

Post by datzenmike »

The VG piston dish is only 1cc and as it has to be trimmed, so it will be a flattop.

All you need is a lobe lift of 0.35" to get 0.525 valve lift and this can be done by regrinding an L20B cam. That's about a tenth on an inch above stock. The spring will stack well before that and likely you'll want stiffer spring anyway. Seems like a lot for a 'street engine' and quite the load on the valve train. What about something more relaxed and with over size valves?
"Nissan 'shit the bed' when they made these, plain and simple." McShagger510 on flattop SUs
dan_the_man2
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Re: 2.1 long rod cam choices

Post by dan_the_man2 »

Thanks Mike, I too thought it sounded a little aggresive. This why I ask. Trying to get a better understanding of what is required for a reasonable combo. In answer to the valves, they are z valves in a closed chamber a87 with little port work done (1 1/2" intake runners).
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defdes
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Re: 2.1 long rod cam choices

Post by defdes »

I had pop up pistons on mine for about a 10.2 compression ratio and from what I remember a 280/510 cam. It was a very nice set up.
The guy at Top End Performance in North Hollywood did the work.
dan_the_man2
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Re: 2.1 long rod cam choices

Post by dan_the_man2 »

Thanks defdes, I get up that way fairly offen. I'll be sure to call them.
Three B's Racing
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Re: 2.1 long rod cam choices

Post by Three B's Racing »

I once ran a Z22 with 10:1 compression, DAMB cam setup, SSS head, Z car ZTherapy SU carbs, properly re-curved EI distributor and all that. Thing ran great no issues, drove it to Summit Point West Virginia from New Hampshire a dozen times and all around these parts no issues. I don't know if Kelvin Dietz still sells the DAMB Cam kit but I can tell you it will be the last cam set up you'll need. That setup works great and best part is properly set up cam geometry with that cam lends a pretty quiet valve train. If memory serves me well the DAMB cam was .520/280 if memory serves me DOH!!
"Lastnight the wife said oh boy when your dead you can't take nothing with you but your soul oh "Think"
- John Lennon
dan_the_man2
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Re: 2.1 long rod cam choices

Post by dan_the_man2 »

Thanks Three B's, as a street car with opperating power in the higher rpm range, did you find it difficult driving in slow traffic?. I was thinking of a 5speed with a rear gear change. Is this necessary or be of much help in that area?
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funwithmonkeys
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Re: 2.1 long rod cam choices

Post by funwithmonkeys »

My car makes all its power above 4000rpm and is easy as pie to drive in slow traffic. I have a 580 lift cam. That being said I am still making over 100 BHP at 3000rpm. It just takes a bit of getting used to. I can roll off the line at my 1200rpm idle every time.
If no one from the future comes back to stop you from doing it then how bad of a decision can it really be?
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defdes
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Re: 2.1 long rod cam choices

Post by defdes »

dan_the_man2 wrote:Thanks Three B's, as a street car with opperating power in the higher rpm range, did you find it difficult driving in slow traffic?. I was thinking of a 5speed with a rear gear change. Is this necessary or be of much help in that area?
5 speed is always nice, I changed from the 3.7 to a 3.9 when I got that motor in and was super happy, i am now looking to go 4.11 with my current FJ20 set up.
This is the 2.2 bored over, long rod I had: https://www.youtube.com/watch?v=QzqBaLhxqUc
dan_the_man2
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Re: 2.1 long rod cam choices

Post by dan_the_man2 »

Thanks guys, that's just what I was hoping to hear. I feared cam and compression at those levels would be a problem.I guess....Game on. I'm looking forward to hunting down all the parts.
Three B's Racing
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Re: 2.1 long rod cam choices

Post by Three B's Racing »

dan_the_man2 wrote:Thanks Three B's, as a street car with opperating power in the higher rpm range, did you find it difficult driving in slow traffic?. I was thinking of a 5speed with a rear gear change. Is this necessary or be of much help in that area?
Not at all in slower traffic other than use of clutch in traffic. In reality it was pretty smooth in traffic at low rpm and I was running 3:90 rear ratio. I was able to run 10:1 compression because we get 91,92,93 and 94 octane fuel here in NH. You being in Cali is a different issue so maybe a bit lesser ratio is in order unless you know a good distributor recurve man.
"Lastnight the wife said oh boy when your dead you can't take nothing with you but your soul oh "Think"
- John Lennon
dan_the_man2
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Joined: 01 Jan 2016 08:48
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Re: 2.1 long rod cam choices

Post by dan_the_man2 »

Three B's, what head chamber and piston where used giving you 10:1? I a lso heard the duration on cam will help high compression motors with detonation. Am I correct in that information?
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