PaulP117 Posted December 9, 2022 Share Posted December 9, 2022 Hey all! The head gaskets on my '91 Reatta have finally kicked the bucket and so I've got the plan to pull the heads off and install some new steel head gaskets. However, before I tear down the engine that far I want to make sure I have the proper torque specs and torque pattern for the heads. I was able to find documentation on most of the engine's various bolt torque specs but I can't find the head torque bolt sequence to know which order to tighten the bolts in. If anyone knows where i can find that head bolt torque sequence I'd appreciate it the help! Link to comment Share on other sites More sharing options...
padgett Posted December 9, 2022 Share Posted December 9, 2022 Bishko has a CD of the 1991 Reatta service manual. Best price is usually on eBay. Link to comment Share on other sites More sharing options...
2seater Posted December 9, 2022 Share Posted December 9, 2022 The engine is actually a true L27 Series I 3800, not the LN3 pre-series I in the other three years. Very minor quibble, but the engine is functionally identical inside, aside from the camshaft drive, rear oil seal and holes in the intake manifold rails of the heads to mate up to the internal PCV system. The intake manifold is quite different. The head gaskets are the same as the LN3, a graphite coated steel core. The head bolts are torque to yield and must be replaced if removed. The head gaskets should come with instructions for the proper sequence, initial torque and final torque angle. My personal suggestion is to use the O.E.M. style head gaskets, Victor Reinz or equivalent in the original style. Do not use Fel Pro as the cylinder hole is too large which will lower compression ratio. If the fire ring in the gasket is completely round, it is the wrong style. 1 1 Link to comment Share on other sites More sharing options...
PaulP117 Posted December 9, 2022 Author Share Posted December 9, 2022 @2seater I've got new head bolts luckily already and it was a pain finding correct looking gaskets until you mentioned the Victor Reinz brand, would you think these would suffice well for the L27 in the 91 Reatta? https://www.autozone.com/gaskets/head-gasket/p/victor-reinz-head-gasket-61-10590-00/1132483_0_0 Link to comment Share on other sites More sharing options...
2seater Posted December 10, 2022 Share Posted December 10, 2022 The photo in that ad is of a FelPro gasket, despite the name. The way things are being consolidated in the auto parts, who knows? This is a photo of the correct gasket. Note that the fire ring is not a perfect circle but is slightly bulged outwards where the intake valve is. To my knowledge, the maximum overbore on a 3800 is .040”, for a 3.84” maximum diameter. The FelPro is round because it is 4.0” diameter. Way too big. It will work, but will cost a couple tenths in compression ratio, which works fine on a boosted engine. Link to comment Share on other sites More sharing options...
PaulP117 Posted December 11, 2022 Author Share Posted December 11, 2022 Ahhhh i see exactly what you mean now by the non-perfect round cylinder design in the gaskets, in my mind i was looking for an egg shape rather then the slight bulge it should have. I definitely will order some of these Victor Reinz gaskets despite the picture being incorrect (hopefully). Ill have to just check and make sure they're shaped correctly once i got them in my hands, thanks for the help by the way i really appreciate it. My Reatta compared to any other cars i've been working on are defintely not as well documented. Thanks to padgett as well for the service manual suggestion, i honestly just assumed all service books for them would've long since been gone Link to comment Share on other sites More sharing options...
dship Posted December 11, 2022 Share Posted December 11, 2022 If you prefer a printed '91 Reatta/Riviera Service Manual, you can also find them on eBay for short money. Link to comment Share on other sites More sharing options...
padgett Posted December 11, 2022 Share Posted December 11, 2022 Nice thing about the Bishko .pdfs is they are the whole thing, searchable, and can put on your phone or a tablet. Link to comment Share on other sites More sharing options...
2seater Posted December 12, 2022 Share Posted December 12, 2022 Here is a more graphic representation of the difference between the gaskets. Hard to get good contrast but there is a Victor gasket under the FelPro. It may help to magnify but essentially the entire fire ring of the Victor is inside the diameter of the FelPro. I noticed I was incorrect and the torque specs and pattern are not with the gaskets but should be with the new bolts🤔 1 Link to comment Share on other sites More sharing options...
dship Posted December 12, 2022 Share Posted December 12, 2022 Many thanks for the info. I just bought 2 sets of Victor head gaskets on eBay that are appropriate for my '91 Reatta. Will put them in inventory. Link to comment Share on other sites More sharing options...
2seater Posted December 12, 2022 Share Posted December 12, 2022 1 hour ago, dship said: Many thanks for the info. I just bought 2 sets of Victor head gaskets on eBay that are appropriate for my '91 Reatta. Will put them in inventory. Well, you should be in great shape since the engine rarely needs to come apart unless you fool around with the insides like I have 👍 1 Link to comment Share on other sites More sharing options...
padgett Posted December 12, 2022 Share Posted December 12, 2022 They will usually turn 7,000 rpm. Once. 1 Link to comment Share on other sites More sharing options...
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