Drag Pak Engines

hemidup · 02-12-2010, 01:19 AM

As far as I know, out of the first 50 DP's built, we have 1 of 5 that were built with a 5.7 Hemi. I can't speak for the other 4, but besides our clearance issues, we have piston problems and currently I don't agree with the recomended solution. Hopefully those issue's were resolved with the later built 5.7's.

On a good note. The stock 5.7 and 6.1 engine and blocks are excellent in both casting and machine work. The quality is impresive and for those that have gone over their blocks with a fine tooth comb will definatly vouch for that. We've been building performance and race app Gen III Hemi's for going on 5 years now. We know them inside and out. Some, like Arlan Vanke and Judy Lilly, consider us pioneer's with the Gen III Hemi aftermarket and new engine designs. We're just 3 dead broke and beaten guy's in a shop, but helped companies like ARP, ATI Super Dampers and Manley develope their prototype Hemi products. In fact those first prototype units are on my personal engine and I still get a chuckle when ARP agreed to make their first run of 10 sets and were very concered about selling them at all. lol We ended up buying 7 and then 15 sets from their next run of 30. Manley did thank us by sending a complimentary set of Nextek series valve springs and titanium retainers for our efforts.

On a side note. For the DYI street/strip builders, these Hemi's can make lots of power on a budget. Complete 5.7 engines are now available cheap from most salvage yards. In fact I just seen one that had low oil pressure for $200. The 5.7 comes with a very stout cast iron crankshaft and if the person so wishes and is lucky, can find a new SRT8 forged 6.1 crankshaft for around $400. If not, Mopar Performance has a forged crank for around $600. Aftermarkert rods and pistons are optional. Stock compression is 9.6:1, but can be brought up by milling the heads. Stock 5.7 heads flow 268 cfm @ 600" lift, but with a good valve job and a simple pocket port will yeild 300 cfm @ 600" lift. Used billet 6.1 camshafts are a dime a dozen, but because of the wide lsa, most opt for an aftermarket stick which are all ground with the 6.1 base circle. That means they'll need 6.1 valve springs (must use 16, 6.1 exh valve springs on 5.7 heads) and pushrods which can be purchased through a dealer for under $100. I've seen many a stock 6.1 valve spring go to 6500 rpm without a failure yet as long as the the lift stayed below .580". BTW, Hopefully they don't loose any retainer locks cause they cost $5 a valve from the dealer and the retainers are .50 cents each. ??? Stock intake manifolds start laying down at 5600 rpm and I still haven't found a good aftermarket one yet. So what can you expect for a buget engine build? I've seen plenty of Hemi full size 4300 lb family sedans running in the 12's with just heads and cam. Now put that engine combo in a lightweight bracket car? Giddy yup!

02-12-2010, 01:19 AM	#16
hemidup Member Join Date: Jan 2010 Location: Minnesota Posts: 409 Likes: 0 Liked 0 Times in 0 Posts	Re: Drag Pak Engines As far as I know, out of the first 50 DP's built, we have 1 of 5 that were built with a 5.7 Hemi. I can't speak for the other 4, but besides our clearance issues, we have piston problems and currently I don't agree with the recomended solution. Hopefully those issue's were resolved with the later built 5.7's. On a good note. The stock 5.7 and 6.1 engine and blocks are excellent in both casting and machine work. The quality is impresive and for those that have gone over their blocks with a fine tooth comb will definatly vouch for that. We've been building performance and race app Gen III Hemi's for going on 5 years now. We know them inside and out. Some, like Arlan Vanke and Judy Lilly, consider us pioneer's with the Gen III Hemi aftermarket and new engine designs. We're just 3 dead broke and beaten guy's in a shop, but helped companies like ARP, ATI Super Dampers and Manley develope their prototype Hemi products. In fact those first prototype units are on my personal engine and I still get a chuckle when ARP agreed to make their first run of 10 sets and were very concered about selling them at all. lol We ended up buying 7 and then 15 sets from their next run of 30. Manley did thank us by sending a complimentary set of Nextek series valve springs and titanium retainers for our efforts. On a side note. For the DYI street/strip builders, these Hemi's can make lots of power on a budget. Complete 5.7 engines are now available cheap from most salvage yards. In fact I just seen one that had low oil pressure for $200. The 5.7 comes with a very stout cast iron crankshaft and if the person so wishes and is lucky, can find a new SRT8 forged 6.1 crankshaft for around $400. If not, Mopar Performance has a forged crank for around $600. Aftermarkert rods and pistons are optional. Stock compression is 9.6:1, but can be brought up by milling the heads. Stock 5.7 heads flow 268 cfm @ 600" lift, but with a good valve job and a simple pocket port will yeild 300 cfm @ 600" lift. Used billet 6.1 camshafts are a dime a dozen, but because of the wide lsa, most opt for an aftermarket stick which are all ground with the 6.1 base circle. That means they'll need 6.1 valve springs (must use 16, 6.1 exh valve springs on 5.7 heads) and pushrods which can be purchased through a dealer for under $100. I've seen many a stock 6.1 valve spring go to 6500 rpm without a failure yet as long as the the lift stayed below .580". BTW, Hopefully they don't loose any retainer locks cause they cost $5 a valve from the dealer and the retainers are .50 cents each. ??? Stock intake manifolds start laying down at 5600 rpm and I still haven't found a good aftermarket one yet. So what can you expect for a buget engine build? I've seen plenty of Hemi full size 4300 lb family sedans running in the 12's with just heads and cam. Now put that engine combo in a lightweight bracket car? Giddy yup!