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Old 03-28-2020, 09:42 AM   #76
OttoB
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Originally Posted by Fred Gwynne View Post
Hi folks,

I purchased a .036" compressed gasket so I think that the tightest squish will be .036" - .007" = .029" after the gasket is installed.

Is that pretty good?



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"Boys" made little error on their own engine calculations. Ended up with 0,02" (is that 20 thou in americanski?) It was B21 roadrace engine, and did not grenade during two seasons.
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Old 03-28-2020, 09:59 AM   #77
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Yeah, that's 20 thou.
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Old 03-29-2020, 06:08 AM   #78
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How much can you skim of the head before you need to worry about the timing belt being too long? - getting some new valves put in & was going to get the head skimmed to tidy it up for the MLS gasket. Now wondering whether to up the compression a bit at the same time.
Tim
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Old 03-29-2020, 12:17 PM   #79
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How much can you skim of the head before you need to worry about the timing belt being too long? - getting some new valves put in & was going to get the head skimmed to tidy it up for the MLS gasket. Now wondering whether to up the compression a bit at the same time.
Tim
Around .060” off the head is where the timing belt tensioner runs out of adjustment.
Good news, timing belts with 1-less tooth (122T, I believe) are pretty common.
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Old 03-29-2020, 12:49 PM   #80
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Cool. Here again are my recommendations from earlier in the thread. With the .036" headgasket and .040" off the head(is that what you went with?), I think you will want to use premium fuel with your KG004/"K" camshaft, at the very least in the summer. You will find out and report back! I look forward to hearing more about your experience. It should move pretty nicely compared to what it used to be. It may want additional tuning there, but you'll also want to advance the cam timing 4 or 6 degrees from the stock position to get you closer to what would be normal and decent low end performance with that head shave/headgasket combo.

You were/are right on the money!
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Old 03-29-2020, 01:21 PM   #81
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Originally Posted by K9 240 View Post
How much can you skim of the head before you need to worry about the timing belt being too long? - getting some new valves put in & was going to get the head skimmed to tidy it up for the MLS gasket. Now wondering whether to up the compression a bit at the same time.
Tim
We have about 0.100" off our head with a 0.036" head gasket. We have a -1 tooth belt installed, and it's TIGHT. If you're not in that ballpark, the regular belt should suffice. I have seen tensioners where the center hole is smaller/larger than others, and this will affect how much adjustment you get out of it.
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Old 03-29-2020, 01:42 PM   #82
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Watch out using a MLS gasket, the stock turbo pistons may stick up out of the block!
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Old 03-29-2020, 04:05 PM   #83
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Originally Posted by Fred Gwynne View Post
You were/are right on the money!
Out of curiosity, do you know where they have it set? Any chance you think you might get it on a dyno one day?
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Old 04-02-2020, 06:06 AM   #84
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Watch out using a MLS gasket, the stock turbo pistons may stick up out of the block!
Are you saying that the piston may hit the gasket?
I'm using a B200 so have the opposite problem! The bore dia is now approx 90mm; gasket dia 92mm & the head 94mm.
I had the block decked so my pistons stick up 13 thou (was 6 thou) so if that's not what you meant I may have a problem.
Tim
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Old 04-02-2020, 05:01 PM   #85
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Out of curiosity, do you know where they have it set? Any chance you think you might get it on a dyno one day?
Hi, yeah they advanced the cam 4 degrees and there is a chance it may end up on a dyno in the future. There is a dyno shop down the road from my home that I should have had my car tested at prior to the mods.
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Old 04-03-2020, 12:19 PM   #86
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Ah, I know of the VX cam from IPD. But, how directly does the A cam compare and where do you get a hold of one in the States?
https://forums.turbobricks.com/showthread.php?t=337956

Post in the "Wanted" section. One will rear its ugly head.
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Old 04-04-2020, 01:21 AM   #87
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Originally Posted by K9 240 View Post
Are you saying that the piston may hit the gasket?
I'm using a B200 so have the opposite problem! The bore dia is now approx 90mm; gasket dia 92mm & the head 94mm.
I had the block decked so my pistons stick up 13 thou (was 6 thou) so if that's not what you meant I may have a problem.
Tim
You're fine, just make sure you're using a stock headgasket or similar thickness. You likely won't want to run a .036" MLS gasket as you'll only have .023" of clearance between the pistons and the cylinder head. The general rule of thumb is to run .028" or more as long as it's less than .040" to maintain the benefits of them being close - good quench/squish. I know people have run tighter without issues, but, it's better to be a little farther than maybe have an issue!

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Originally Posted by Fred Gwynne View Post
Hi, yeah they advanced the cam 4 degrees and there is a chance it may end up on a dyno in the future. There is a dyno shop down the road from my home that I should have had my car tested at prior to the mods.
Sweet! I'd love to see what it does at some point. Regarding pre-mod numbers, you're probably looking at between 75-105whp depending on what camshaft was in it(B?), general state of tune/condition and if automatic or manual. My completely stock '91 244 with an automatic and V15 cam did 94whp.

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Originally Posted by shoestring View Post
https://forums.turbobricks.com/showthread.php?t=337956

Post in the "Wanted" section. One will rear its ugly head.
I looked at the last page and couldn't find the post you referenced, until I looked on the first page, hah. It was from 2017 so who knows if he's been back. I'll add that the VX is a newer profile camshaft with similar performance to the A and a better idle. I'd probably want the A for performance, as long as you don't have extremely stringent emissions testing. Even with it, it's probably fine. But, like Shoestring would tell anyone, the V makes for a nicer cam than the A.
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Old 04-04-2020, 12:44 PM   #88
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Werd. A MAF wants as much lobe seperation as you're willing to give it. Ask any Tuned Port guy from the 80's.
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Old 04-06-2020, 04:30 PM   #89
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Werd. A MAF wants as much lobe seperation as you're willing to give it. Ask any Tuned Port guy from the 80's.
Does a larger plenum after the MAF help with the increase in intake volume? I guess that might also make the engine management would respond slower. Meh.
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Old 04-07-2020, 12:19 PM   #90
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Dude I have had a mental wrestling match with plenum sizing for a very long time. It seems more definitive in a turbocharged application. In an injected N/A application, I've read a ton of theories, but I haven't really seen anything that makes me say "Aha. This is what I've been looking for." I can specifically remember one example that said something like "anywhere from 300 to 3000cc plenum size", which didn't really make sense to me.

If you've got some real info on this, I've love to look at it.
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Old 04-07-2020, 01:24 PM   #91
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If you've got some real info on this, I've love to look at it.
Here you go: https://grapeaperacing.weebly.com/te...-articles.html
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