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bugedd
04-21-2011, 10:06 AM
I was thinking that while I have my motor out while I rebuild my trans, I may put a lumpy cam in the 1275. I had a guy tell me that even the stock cams can flatten out over time, reducing lift/duration, so now might be the time to cam it.

What I would like is something mild/moderate, streetable, but noticably lumpy and peppy. Any suggestions on what to get? The car is a driver, so low to mid range power band is what I am after. And do all 1275's use the same cams, or is there some variation? Carburation is a Weber DGV if that has any influence, header is on the car as well.
Thanks

drooartz
04-21-2011, 10:30 AM
Hap used an APT VP276 cam (similar to the Kent MD276) on my 1275 build. Here's a link to a bunch of notes from Hap's build of my motor.

https://www.drooartz.com/index.php?page=44.3

Gundy
04-21-2011, 10:46 AM
I have no idea what cam to use but if you are doing a cam
change I'd suggest a vernier adjustable timing chain
to get the most out of the cam.
Having a Pro port and polish the head is a good idea too.
I'd think the cam is just part of an overall concept of what you want. Ton-o-variables here.

Bob Claffie
04-21-2011, 11:01 AM
Most "lumpy" cams take away low and mid-range torque so you might be shooting yourself in the foot. Sounding good and running good are not the same. Do you want to enjoy driving your car or impressing everyone with your racing sounding motor ? Best cam for bopping around town is a "taxi" cam, designed for low speed grunt that sacrifices power over 3500 / 4000 rpm. Bob

bugedd
04-21-2011, 04:40 PM
Down the road, I intend to rebuild the motor and do some head work, but that is perhaps in a year or three :smile: I know what you mean about the lumpy cams being more of a high rev powerband cam. I just want to see how far I can go before I lose the low end. I was also hoping someone out there may have a good used for for a good price :smile:

porterthe
04-21-2011, 06:29 PM
There is a vociferous group that swear if you use modern oil for break in you will flatten the cams very quickly.

Spridget64SC
04-22-2011, 09:48 AM
Streetable cams stay under 245 degrees duration at 0.050" lift, 0.305" lift at the cam and lobe centers in the 106-109 range. Anything with more Duration and Lift and Tighter Lobe Centers than that and you won't like the drop in low end performance.

The reason I used the 0.050" figure in the above is that cam patterns can get up as high as 290+ on advertised duration and still be streetable.

The safest and most straight forward thing to do is to buy a cam kit. One with cam, lifters, springs and such, all matched for the application. Old stock valve springs that are still good are as rare to find. APT, Kent, Piper are all the usual suspects for cam kits. I can make one up too using a Comptune selected ISKY pattern. The "270-X" kits are about the limit before you begin to feel the loss of low end performance. The last Rover cam for the A-series engine was a pretty peppy cam and didn't sacrafice much if anything at the bottom. Performance quits at about 6300 rpm. And, that's higher than most people will ever turn a street engine. ISKY has a pattern that is very similar to the Metro cam and I've had a number of these cams ground to my lobe center specification.

The oil issue is a whole subject in itself. When you get ready to pour oil in the engine, then research that one.

2091351
04-22-2011, 04:20 PM
My Brother, LeeCreek on the Forum, runs one of Mikes CAMS in his 1293cc.

Nice!! :cheers:

Steve
:driving:

bugedd
04-22-2011, 09:39 PM
Mikes cams? Who is Mike?

2091351
04-23-2011, 08:49 AM
Spridget64SC

Hap Waldrop
04-24-2011, 06:47 AM
I build alot of MG 1275 performance street engines, and have built several for posters on this forum, I like APT VP276 grind, David use late model slot drive drive A+ cam cores regrinds them and then Ion nitrites them, and that is exactly what Drew has in his engine that I built.

I do use Mike (Comptune) cams as well, but in race engines.


FWIW, many of you may remember Ray McCaleb that post here alot, had a website, raysmg.com where he was building a Midget street racer, many of you may remember I built a pretty trick 1275 for Ray, lotsand lots of goodies, rumor has it Ray has abandoned the project, as well as the car hobby and wants to sell the engine, ans well as other things. Just so you all know. I probaby see one of buddys at the Mitty next week and get more info on this.

drooartz
04-24-2011, 09:39 AM
Someone should pick up Ray's engine if he is indeed selling it off. Quite similar to my build with a few more goodies. It'd be as good a street 1275 as you could get. I'm certainly quite happy with mine.

Sorry to hear Ray's getting out of the hobby, but things do change in one's life.

bugedd
04-24-2011, 10:07 AM
Buying the motor would be great, but probably out of my price range. But worth looking into. If you don't mind, keep me posted