HEMI ENGINE BUILDER QUESTION - Moparts Forums

Register Log In Moparts Forums Unlawfl's Race & Engine Tech HEMI ENGINE BUILDER QUESTION

Print Thread

HEMI ENGINE BUILDER QUESTION #1206446 03/30/12 02:03 PM 03/30/12 02:03 PM
Joined: Apr 2005 Posts: 1,505 TN S SCATPACK 1 OP pro stock
SCATPACK 1 OP pro stock S Joined: Apr 2005 Posts: 1,505 TN	This is directed to the experienced Engine Builders. Regarding the thickness of the piston dome or surface. We are working with a 572 Hemi and Indy's newest designed Hemihead, their HIPO head that has 2.40 intake valves flowing 450 with a roller cam 278/282* @50 with 800 lift. Shooting for just under 14-1 compression. My brother just received a second set of Weisco Pistons and they do not have the valve to piston clearance he requested again. He was very specific with the person he spoke with on what we were using for the head and cam combo. Here is my question, IF I machine the intake valve side of these pistons to clear the intake valves, what is my minimum piston thickness on the dome/valve relief? Can we go down to 100 thousands or should we try to maintan at least 200 thousands for piston dome/deck thickness. I want at least 90 thousands piston to valve clearance on the intake valves but to get this, we will have to cut the reliefs about 200 thousands. Both sets of pistons the mfg has sent to us, there is zero clearance on the intake valves even without the cam opening the valves. PLENTY of clearance on the exhaust, but they can't seem to get the intake valve area right. The intake valve on these HIPO heads appear to sit further out of the combustion chamber, but I don't have another set of heads to compare them to. The person on the phone at Weisco said they had a piston designed just for this head but it does not seem they fit very well. I have not miked the thickness of the piston dome yet, so I don't even know if I can cut them this much. What say the experts on these pistons, How thin can you safely run the piston surface/dome area before you experience breakage. Old Geezer Racing

Re: HEMI ENGINE BUILDER QUESTION [Re: SCATPACK 1] #1206447 03/30/12 02:14 PM 03/30/12 02:14 PM
Joined: Jan 2003 Posts: 6,392 nielsville, minn. Q quickd100 master
quickd100 master Q Joined: Jan 2003 Posts: 6,392 nielsville, minn.	I'd call Wiseco and talk to their tech guy to find out how much you can mill the valve reliefs. I'd also ask if they could set you up with the correct pistons first. Dave

Re: HEMI ENGINE BUILDER QUESTION [Re: quickd100] #1206448 03/30/12 02:19 PM 03/30/12 02:19 PM
Joined: Jan 2003 Posts: 13,362 Marion, South Carolina [><] an8sec70cuda I Live Here
an8sec70cuda I Live Here Joined: Jan 2003 Posts: 13,362 Marion, South Carolina [><]	I think I'd send them back to Wiseco and get my money back. Then go to a piston manufacturer who knows what they're doing. Or just call Dan (DRAM) at Performance Only and he'll hook you up w/ a good set of Diamond pistons. CHIP '70 hemicuda, 575" Hemi, 727, Dana 60 '69 road runner, 440-6, 18 spline 4 speed, Dana 60 '71 Demon, 340, low gear 904, 8.75 '73 Chrysler New Yorker, 440, 727, 8.75 '90 Chevy 454SS Silverado, 476" BBC, TH400, 14 bolt '06 GMC 2500HD LBZ Duramax

Re: HEMI ENGINE BUILDER QUESTION [Re: an8sec70cuda] #1206449 03/30/12 06:28 PM 03/30/12 06:28 PM
Joined: Jul 2010 Posts: 2,091 Delray beach, Florida P Performance Only top fuel
Performance Only top fuel P Joined: Jul 2010 Posts: 2,091 Delray beach, Florida	Quote: I think I'd send them back to Wiseco and get my money back. Then go to a piston manufacturer who knows what they're doing. Or just call Dan (DRAM) at Performance Only and he'll hook you up w/ a good set of Diamond pistons. Chip, thanks for recommending me. i'm pretty sure we've done over 100 sets of custom pistons just for guys here on Moparts over the years. SCATPACK1, what are the pocket depths right now on your pistons? also, did anyone ask you to measure the valve drop on those heads before making the pistons? let me know if i can help. Last edited by Performance Only; 03/30/12 06:31 PM. machine shop owner and engine builder

Re: HEMI ENGINE BUILDER QUESTION [Re: Performance Only] #1206450 03/31/12 01:19 AM 03/31/12 01:19 AM
Joined: Jan 2003 Posts: 2,431 USA S SSAAHemiFan top fuel
SSAAHemiFan top fuel S Joined: Jan 2003 Posts: 2,431 USA	Not a engine pro pro but NO way would I run a dome that thin (.100) - friend had a set cut down years ago in a street hemi that left him .150 on average but of course it was evern thinner in some of the reliefs. Was always nervous running it and spent alot of time making sure the tuneup was spot on. 200 thou (.200) is the break point for me personally, more if it has a power adder.

Re: HEMI ENGINE BUILDER QUESTION [Re: SSAAHemiFan] #1206451 03/31/12 02:11 AM 03/31/12 02:11 AM
Joined: Sep 2004 Posts: 1,828 houston texas G gremlinsteve top fuel
gremlinsteve top fuel G Joined: Sep 2004 Posts: 1,828 houston texas	id call and talk to vic at wiseco. if You Like Gremlinsteve. Gremlinsteve Likes You.

Re: HEMI ENGINE BUILDER QUESTION [Re: gremlinsteve] #1206452 03/31/12 01:28 PM 03/31/12 01:28 PM
Joined: Mar 2003 Posts: 1,629 pa 572charger top fuel
572charger top fuel Joined: Mar 2003 Posts: 1,629 pa	i had c-p pistons i had 2 cut the intake pockets about 50 thou still had about 300 thou thick dome , my diamonds are spot on !!!!! call diamond 606 hemi pump gas best 9.60 at 142mph on motor 05 hemi daytona 1500 go-mango 4wd quadcab 2007 hotrod mag pump gas drags runner up, roadkill nights dodge big tire winner 2018 2019 back to back

Re: HEMI ENGINE BUILDER QUESTION [Re: 572charger] #1206453 04/01/12 07:28 AM 04/01/12 07:28 AM
Joined: Mar 2006 Posts: 9,910 Eighty Four, PA B G Racing master
B G Racing master Joined: Mar 2006 Posts: 9,910 Eighty Four, PA	Depending on cam lift,deck height,head CCs as well as head gasket thickness this is a must to check and varify.If buying custom pistons always ask for extra valve clearence and still check. [IMG]http://i430.photobucket.com/albums/qq21/ajcasini/max_zpsdppwd9km.jpg[/IMG]

Re: HEMI ENGINE BUILDER QUESTION [Re: B G Racing] #1206454 04/01/12 01:14 PM 04/01/12 01:14 PM
Joined: Jan 2003 Posts: 3,504 DFW M mr_340 master
mr_340 master M Joined: Jan 2003 Posts: 3,504 DFW	I bought some Diamond 52550 Hemi pistons and my machinist measured the dome thickness at the valve notches. It was around .18" thick, so if I run into any valve-to-piston clearance issues I'll probably have to change to a cam with a wider LSA. I don't think I want to go any thinner on my first Hemi build. Floyd Lippencott IV

Re: HEMI ENGINE BUILDER QUESTION [Re: SCATPACK 1] #1206455 04/01/12 01:56 PM 04/01/12 01:56 PM
Joined: Aug 2003 Posts: 43,157 Bend,OR USA C Cab_Burge I Win
Cab_Burge I Win C Joined: Aug 2003 Posts: 43,157 Bend,OR USA	Years ago I heard of a SS Racer(Dave Wren) having to weld up the top of a piston that was .120 thick, he had bougt a car that had those pistons in them and the previuos owner had mill and finshed the tops of the pistons. Dave had not done them that way intentionally, he siad they look like baseballs, with valve reliefs not like pistons he had run before they had passed tech in the tear down for the class win at that years Winternational Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)

Re: HEMI ENGINE BUILDER QUESTION [Re: SCATPACK 1] #1206456 04/02/12 11:33 PM 04/02/12 11:33 PM
Joined: Nov 2010 Posts: 914 tn R robnbird super stock
robnbird super stock R Joined: Nov 2010 Posts: 914 tn	Quote: This is directed to the experienced Engine Builders. Regarding the thickness of the piston dome or surface. We are working with a 572 Hemi and Indy's newest designed Hemihead, their HIPO head that has 2.40 intake valves flowing 450 with a roller cam 278/282* @50 with 800 lift. Shooting for just under 14-1 compression. My brother just received a second set of Weisco Pistons and they do not have the valve to piston clearance he requested again. He was very specific with the person he spoke with on what we were using for the head and cam combo. Here is my question, IF I machine the intake valve side of these pistons to clear the intake valves, what is my minimum piston thickness on the dome/valve relief? Can we go down to 100 thousands or should we try to maintan at least 200 thousands for piston dome/deck thickness. I want at least 90 thousands piston to valve clearance on the intake valves but to get this, we will have to cut the reliefs about 200 thousands. Both sets of pistons the mfg has sent to us, there is zero clearance on the intake valves even without the cam opening the valves. PLENTY of clearance on the exhaust, but they can't seem to get the intake valve area right. The intake valve on these HIPO heads appear to sit further out of the combustion chamber, but I don't have another set of heads to compare them to. The person on the phone at Weisco said they had a piston designed just for this head but it does not seem they fit very well. I have not miked the thickness of the piston dome yet, so I don't even know if I can cut them this much. What say the experts on these pistons, How thin can you safely run the piston surface/dome area before you experience breakage. WHAT DO YOU THINK ABOUT MAKING A MOLD OF THE C/ CHAMBER AND SEND IT TO SAY J&E TO MAKE A SET. HUM THAT WILL WORK. I JUST WANT TO ASK A QUESTION? ARE YOU ONE OF THE ORIGINAL SCAT PACK GUYS HERE IN TN FROM BACK AROUND 1970. 7148923-mocar.jpg (53 downloads)

Re: HEMI ENGINE BUILDER QUESTION [Re: SCATPACK 1] #1206457 04/04/12 06:22 PM 04/04/12 06:22 PM
Joined: Nov 2010 Posts: 914 tn R robnbird super stock
robnbird super stock R Joined: Nov 2010 Posts: 914 tn	ARE YOU ONE OF THE 1970 SCAT PACK GUYS ? 7151489-OldDragPicture.jpg (85 downloads)

Re: HEMI ENGINE BUILDER QUESTION [Re: robnbird] #1206458 04/04/12 06:54 PM 04/04/12 06:54 PM
Joined: Apr 2005 Posts: 1,505 TN S SCATPACK 1 OP pro stock
SCATPACK 1 OP pro stock S Joined: Apr 2005 Posts: 1,505 TN	Yes I was. Boy does that picture bring back memories. Where did you come up with that old Drag Review photo. That pic is from an IHRA Points meet. We had won several IHRA Superstock races in a row and Jimmy Johnson, the IHRA publicity director guy did an article on my car with the best 4 speed driver in the south. Feared by many including Roy Johnson, John Wayne and Clint Eastwood (but don't tell him I said so) LOL Old Geezer Racing

Re: HEMI ENGINE BUILDER QUESTION [Re: SCATPACK 1] #1206459 04/04/12 07:05 PM 04/04/12 07:05 PM
Joined: Nov 2010 Posts: 914 tn R robnbird super stock
robnbird super stock R Joined: Nov 2010 Posts: 914 tn	Quote: Yes I was. Boy does that picture bring back memories. Where did you come up with that old Drag Review photo. That pic is from an IHRA Points meet. We had won several IHRA Superstock races in a row and Jimmy Johnson, the IHRA publicity director guy did an article on my car with the best 4 speed driver in the south. Feared by many including Roy Johnson, John Wayne and Clint Eastwood (but don't tell him I said so) LOL I thought you were one of those guys.and yes that guy could flat drive, I never saw anyone any better 7151540-OldDragPicture.jpg (43 downloads)

Re: HEMI ENGINE BUILDER QUESTION [Re: Performance Only] #1206460 04/06/12 07:20 PM 04/06/12 07:20 PM
Joined: Oct 2009 Posts: 276 Temecula, Ca. Z zzyzxpat enthusiast
zzyzxpat enthusiast Z Joined: Oct 2009 Posts: 276 Temecula, Ca.	You did mine Dan for a stroked 361. You were a gentleman to deal with, gave me alot of info, and was very pleased with the price, service, and quality. Pat " The last official act of any goverment, is to loot the treasury" George Washington

Moderated by Al_Alguire, Hotwheelsjr, moparts, not_a_charger, RangerDan440, tboomer

Hop To

Powered by UBB.threads™ PHP Forum Software 7.7.1