Hemi (2nd Gen) Questions

[TetanusShot]

I'm just going to ask three for starters.

1. What cam are you guys running in your street driven Hemis?

The cam will be for: factory street hemi heads, alum dual plane, and manual disc brakes. Target cr is 9:1-9.5:1, and 471ci.

2. What style of oiling are you using: stock style, through the pushrods, spray bar, or a combination?

Currently budgeting for Indy's roller rocker setup.

3. Are there issues with cooling the siamese blocks?

For reference, I put 8500 miles on the car last summer, and I hit the drag strip every now and then. I intend to do the same with this engine too.

Thanks everybody

 

[Bigal75]

I can answer a few...I'm using the stock style oiling with a regular oil pump factory style rockers.

I'm running a 572 and was having cooling issues but nothing that has anything to do with the engine - my clutch fan was deffective and my rad was all crusted up. Car idles at 170 and now doesn't go over 200.

 

[Hemirunner]

I'm just going to ask three for starters.

1. What cam are you guys running in your street driven Hemis?

Al has an RBRE flat tappet with 280/280 @ .050. You won't have enough compression to run that big of a cam.

The cam will be for: factory street hemi heads, alum dual plane, and manual disc brakes. Target cr is 9:1-9.5:1, and 471ci.

9:1 in a hemi is for power adder combos. A 9:1 hemi is a slug on the street. I'd run 10:1 with that combo and cam accordingly.

2. What style of oiling are you using: stock style, through the pushrods, spray bar, or a combination?

Currently budgeting for Indy's roller rocker setup.

I currently run oil through pushrod with Indy heads and rockers. If you have the budget, I'd have the edelbrock heads on it, more compression in it, and put a good rocker, like a RBRE on it. The indy setup is ok, but not even in the same ball park as the RBRE. It'll eliminate all the oil piling up on the top end like the stock setups tend to do. If you run Indy heads, you can restrict it.

3. Are there issues with cooling the siamese blocks?

None.

For reference, I put 8500 miles on the car last summer, and I hit the drag strip every now and then. I intend to do the same with this engine too.

Thanks everybody

You can do that with any of them if built right.

- - - Updated - - -

Also, if you put better heads on it, get rid of the dual plane intake and go with the StageV single plane. At 471 inches, you'll have enough torque that you won't need a dual plane. Tuning will be much easier also without that power robbing stock intake.

 

[TetanusShot]

280 @ .050??? Holy mackerel. I'm building a street motor. Did you mean 280 advertised duration?

I went with the dual plane for good streetability and to fit under a stock hood (70rr), plus they're cheap because nobody wants them.

I did actually plan the build around edelbrock heads initially, but their installation instructions say a minimum bore of 4.380 and the valve reliefs in the pistons need clearance for the bigger intake and tipped exhaust angle.

Ordered the non-adjustable indy setup yesterday. Think i'll take your advice and bump up the target compression. Nothing is set in stone yet other than the parts I already have.

A big thank you for your input

 

[Bigal75]

283 @0.50 - LOL sounds wicked! revs ultra quick and pulls big time!

 

[Hemirunner]

That thing revs like a small block!

 

[TetanusShot]

Received my Indy rocker system in the mail yesterday, the oil feed holes in the shaft don't line up with the holes in the exhaust rockers. Even if they did line up, the weep hole points toward the pushrod side. How on earth are the exhaust rollers supposed to get oil? Splash only?

Pretty discouraged

For Indy's sake I will say that the rest of the kit looked great and they shipped it fast.

 

[Hemirunner]

Yes, the indy rockers are splash only to the roller and they'll get enough oil.

 

[TetanusShot]

Okay, after completely mocking up one assembly on a head, not a single oil feed is aligned with any of the rocker's weep holes.

Should I try drilling/grinding new holes in the right places in the hardened shafts, take the problem up with Indy, or go with oil through pushrods?

I can't believe they don't use fixtures to machine these holes so nobody can screw them up.

 

[Meep-Meep]

I recently picked up a hemi built by XRE Performance Engines and it came with a very detailed spec sheet. Cam is a Comp roller XR286HR10 and compression is 9.55:1. Dyno results are 493 HP @ 5400 RPM and 502 ft lbs at 4700 RPM with (one) 800 CFM Eddy carb on the repo NASCAR dual plane intake. Currently it's running the stock 2 4BBL setup that I still need to dial in. I have no idea who XRE Engines is so if someone could enlighten me it would be appreciated. I googled the name and closest I got was XTreme Racing Engines on FB. The name on the card is Tom Ghent. But for what it's worth it seems to run well but is no powerhouse. Again, I'm sure it's because the carbs are not fully dialed in or I have some other issue that needs sorting out.