Suggested stall for converter

smokenjoep01 · #1 03-09-2011, 07:43 PM

I was wondering what the general referances are for a stall converter for my little 307ci build. Its 30 over with a small cam. The machinest and guy that ordered my parts said to use a Z28 converter. Best I recall he said 1600-2000. I will post the cam specs from the card.

Highway Star · #2 03-09-2011, 07:59 PM

That is a pretty big cam for a 307...a lot more than I expected to see when you said 307 and small cam. In a 350, you'd probably want a 3000 rpm stall for that cam. What kind of compression are you running? What is the gear ratio?

smokenjoep01 · #3 03-10-2011, 06:14 AM

Another gear head buddie of mine said the same thing. I told the motor guy that I just wanted a mild bump up from stock. The comp ratio is still same as stock. Not sure of the gear ratio. The car most likely still has the same gear that came with the PG and 307.

Rattler · #4 03-10-2011, 12:27 PM

That's just a nice step up from a stock cam. I'd look for a 1800-2000 converter for it just for some added performance, but I bet a stock converter will work fine. Who makes the cam? you can compare the specs on it to comp cams with their online cam suggestion guide to give you an idea of the converter you want to use.

smokenjoep01 · #5 03-10-2011, 01:03 PM

Rattler, Thanks thats a bit of a releif. I was thinking this was a huge cam with no vacuum for street driving. Just a bump up from stock was all I was looking for. The cam is a Erson #E110044

Rattler · #6 03-10-2011, 01:56 PM

Your vacuum will be lower then normal and it will have a noticeable idle, but should be nice in your setup. If you can go up a bit on the converter it would help out.

Highway Star · #7 03-10-2011, 07:59 PM

230/230 is the same thing as an old school comp 280H Magnum cam, but your cam looks like it is on a 108 LSA instead of the 280H's 106 LSA. Comp's website says

"Hydraulic-Great for Street Machines. Needs stall, headers & gears. Rough idle."

Now my thinking on this is that you're sticking it in a 307. Cams act bigger in smaller engines, right? That means it will be choppier and have less "manners" in a 307.

I'm saying that the cam isn't optimally matched to your setup. When most people talk sbc cams, they refer to them by the advertised duration numbers. Yours is a 292. When I thought of a small cam for a 307, I was thinking 252. There are about 10 cam sizes in between those two.

You can put together a small inch smallblock with a biggish cam, but you need enough static compression to make power with it. You may be around 8.5:1. The more duration, generally the more CR you need. It is a 292 cam, this is what Isky says about their 292 cam...in a 350

"292 Mega Hyd.
Compression Ratio: 10-11:1
Rough Idle
RPM range:3000-7000
recomended gear ratio: 4.11/4.56
Carburetor rating: 650-780
Combination Hi-Performance Use/Bracket"

A stock cam for a 307 probably has specs something like this:

Duration @ .050" = 190°/190°
Lift @ .050" = .390"/.400"
LSA: 114

Look at this page, it calls out the specs on your erson cam...

http://www.pbmperformance.com/store.php?catId=327

All the sbc cams above it are smaller. I'm not telling you not to put it in, I'm saying that it isn't small.

smokenjoep01 · #8 03-11-2011, 06:29 AM

Thinner head gasket?

Highway Star · #9 03-11-2011, 07:31 AM

That will help a little. Do you know the casting number on your heads?

smokenjoep01 · #10 03-11-2011, 08:24 AM

Not sure of the number. The machinest looked at them and told me they were stock for the 307= small. Im thinking I may just belly up for a comp cams 268 duration. Anyone interested in a Erson 290?