What Head Gasket to use
Thread Starter
Melting Slicks
Joined: May 2007
Posts: 3,246
Likes: 4
From: Bay Area CA
What Head Gasket to use
I'm soon (hopefully) going to be doing a full top end rebuild. I have gotten some conflicting advice on what head gaskets to use, there isn't a tight budget for them, so please give your educated opinion:
Heads: Brodix IK-180s
http://store.summitracing.com/partde...5&autoview=sku
Rockers: Full Roller
http://store.summitracing.com/partde...t=LUN-85300LUN
Manifold: Edel perf
http://store.summitracing.com/partde...?part=EDL-2101
Cam: Lunati 256
http://store.summitracing.com/partde...rt=LUN-60101LK
All going onto a 100% stock L48 bottom end.
Some have recommended a head gasket with a .041 compressed height:
http://store.summitracing.com/partde...?part=FPP-1003
But other have said that it is too high, and recommend a gasket with a height of between .028 and .015. I will be running the car on pump 91ron gas,, what should i use?
I want a good head gasket that's Not going to blow out. Also, any suggestions on how to treat the old and new matting surfaces to get a good hold- techniques for cleaning the block side? Thanks,, C.
Heads: Brodix IK-180s
http://store.summitracing.com/partde...5&autoview=sku
Rockers: Full Roller
http://store.summitracing.com/partde...t=LUN-85300LUN
Manifold: Edel perf
http://store.summitracing.com/partde...?part=EDL-2101
Cam: Lunati 256
http://store.summitracing.com/partde...rt=LUN-60101LK
All going onto a 100% stock L48 bottom end.
Some have recommended a head gasket with a .041 compressed height:
http://store.summitracing.com/partde...?part=FPP-1003
But other have said that it is too high, and recommend a gasket with a height of between .028 and .015. I will be running the car on pump 91ron gas,, what should i use?
I want a good head gasket that's Not going to blow out. Also, any suggestions on how to treat the old and new matting surfaces to get a good hold- techniques for cleaning the block side? Thanks,, C.
Race Director
Joined: May 2005
Posts: 10,674
Likes: 122
From: Millington Illinois
St. Jude Donor '08-'09
Felpro 1094. ,015 compressed thickness for perfect .040 quench in your build and recommended for aluminum heads.
And your cam is too small.
And your cam is too small.
Last edited by 63mako; May 14, 2009 at 11:25 AM.
Le Mans Master
Joined: Apr 2005
Posts: 6,360
Likes: 429
From: Seattle Area WA
GM ZZ4 comes with the .028" gasket with stainless faces. The FelPro 1094 is a steel shim that is Hypalon coated to prevent galvanic corrosion and brinneling and is recommended by Fel Pro for use with Al heads, and as we have already discussed in the last thread, provides you with the best quench of all the gaskets that have been tossed around so far.
I would also use a slightly bigger cam with your combo as well. I've already recommended the Engle 1018H which flat out kicks a** with this combo.
I would also use a slightly bigger cam with your combo as well. I've already recommended the Engle 1018H which flat out kicks a** with this combo.
Pro
Joined: Jun 2005
Posts: 725
Likes: 1
From: FL.
Your Brodix IK's is a great choice. Low rise edel Manifold is good choice.
But
The gasket choice is crucial since you are Buiding on a L48 Low end.
Before you choose a gasket Measure How deep your pistons set in the hole at TDC. The fel 1094(.015) is very skinny, and Must have a near perfect flat Deck to set on. Plus it will raise the CR alot.
For example My engine's pistons sit .020 in the hole and with Bodix 64cc heads and the Fel-1094 I get a little over 10 to 1 Compression Ratio. Which is fine for 400 HP on pump gas. But may not be fine For your stock 180hp engine.
Your cam choice is too small like Mako said. You could run reliably If you plan your top end to give you 300HP. the comp. 264h cams are about Ideal with Holley 670 SA . And a gasket that would Keep the CR to 9 to 1, or maybe a little lower. To much CR could knock your old Bottom end out quickly if you wanted to burn some rubber ect.
Hope this helps..
But
The gasket choice is crucial since you are Buiding on a L48 Low end.
Before you choose a gasket Measure How deep your pistons set in the hole at TDC. The fel 1094(.015) is very skinny, and Must have a near perfect flat Deck to set on. Plus it will raise the CR alot.
For example My engine's pistons sit .020 in the hole and with Bodix 64cc heads and the Fel-1094 I get a little over 10 to 1 Compression Ratio. Which is fine for 400 HP on pump gas. But may not be fine For your stock 180hp engine.
Your cam choice is too small like Mako said. You could run reliably If you plan your top end to give you 300HP. the comp. 264h cams are about Ideal with Holley 670 SA . And a gasket that would Keep the CR to 9 to 1, or maybe a little lower. To much CR could knock your old Bottom end out quickly if you wanted to burn some rubber ect.
Hope this helps..
Le Mans Master
Joined: Apr 2005
Posts: 6,360
Likes: 429
From: Seattle Area WA
If you use 64cc heads on a typical L-48 with 13cc dished pistons that sit the standard .025" down in the hole, a GM .028" thick head gasket with a 4.00" bore your resultant compression ratio is ONLY 9.15:1 and using the Engle cam for example with 216/226 108 ICL/ 112 LSA your DCR is only 7.69:1 I would Not run a longer duration cam at this low compression.
That cam's power band is 1500-5500, perfect for a L48 bottom end.
If you use the 1094 at .015" with a 4.1" bore, your compression ratio will increase to 9.39:1. It does not increase the compression very much, optimizes the quench, and squeezes a bit more out of the installation. Same cam, the DCR is 7.88:1.
Both combos will be fine with pump gas and you probably wouldn't notice much difference between the two. Hands down the GM gasket is a better part and will offer decent quench for this application.
That cam's power band is 1500-5500, perfect for a L48 bottom end.
If you use the 1094 at .015" with a 4.1" bore, your compression ratio will increase to 9.39:1. It does not increase the compression very much, optimizes the quench, and squeezes a bit more out of the installation. Same cam, the DCR is 7.88:1.
Both combos will be fine with pump gas and you probably wouldn't notice much difference between the two. Hands down the GM gasket is a better part and will offer decent quench for this application.
Le Mans Master
Joined: Sep 2001
Posts: 7,739
Likes: 630
From: Unreconstructed, South Carolina
A pr of aluminum GM L98 aka ZZ4 heads are 163cc w/ 58cc chambers & are also a good mate to L48 lower & intake ... in an OE L48 app 58cc will raise scr approx 0.6 above 64cc chambers ... I see about 9.6:1 w/ 0.028".
-edit- IMO, roller rockers, roller tip and/or roller trunnion in above motor is a big waste of $ ... Plain stamped will do just fine in above. I understand you've got the dough ... but why waste it ... heck, get new stamped & donate to charity.
Last edited by jackson; May 14, 2009 at 05:05 PM.
Thread Starter
Melting Slicks
Joined: May 2007
Posts: 3,246
Likes: 4
From: Bay Area CA
Thanks to all for the replies. I'm going to run the GM .028. I know the cam is a bit smaller, I am after more low end torque and a smoother running engine. my other choice was the Lunati 262h, but settled on the 256 for reasons above. For the Engle cam, i can't find it anywhere, google won't pull any ref to it up either. Thanks,, C.
Le Mans Master
Joined: Apr 2005
Posts: 6,360
Likes: 429
From: Seattle Area WA
They are in Santa Monica, if you call and talk to Doug or Mark Engle, the sons of Jack Engle, you are calling the guys who are going to grind you a cam, not some guy in front of a screen.
http://www.englecams.com/index.php
http://www.englecams.com/index.php
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