Now that I've got some BRAP... I have a few ???

[Shifty]

I installed my pipe and head friday night, no real problems except the riva girdle hardware sucks. The girdle bolts didn't align well with the case bolts and one entered at an angle and jacked the threads up a little... long story short I installed everything loosley and they torqued the head. After a bunch of trimming to the stock F/A base and cover it able to fit nicely. The Limited pipe went on super easy, except for the two top/center bolts.

Before I launched I stopped by the marina to run a comp test on this head, 195psi on 35cc domes, what the!!!:dunno: This was supposed to run on pump gas and I am running it on pump gas, 93 octane. His comp tester also had the short threads on it so I am affraid I am in the 200psi zone. These domes were originally stamped 29cc and that was X'd out and hand scribed by RIVA with 35cc's. The guy doing the comp test held the guage while I did the test, one plug installed, full throttle, dead even psi readings. No telling about his guage, he was a dumbass... I told him I was worried about detonation, he told me to "just tighten up the high speeds"

I will try and get another comp. tester to check with. For my question, is it safe to run at 195psi? Brand new engine, no chokes, limited pipe and this riva head....

 

[ski4]

I myself would not. Till at least you verify that reading on another guage

t

 

[Shifty]

I did a plug chop and swam it in, keep in mind this was a fresh set of plugs near the end of my first tank. The plugs were mostly white with a little pink to light tan coloration on the side of the tip, the threaded rim of the plug was dry with some black carbon deposits on it.

What does detonation look like?

I am not running this thing all out except for a few short bursts here and there.

 

[Shifty]

I though that both plugs gave a better reading because of the faster RPM's the engine turns. And wouldnt the extra volume the short threads this comp tester had allow a lower reading than when there is a 3/4" spark plug in there?

 

[YAMA CAT]

This your 08' you are talking about. We did a compression test on my 08' and it seem to have 10-15 more PSI than previous years. I'm not sure if the gaskets are a different thickness or the stock head is milled but the compression is higher. This maybe the reason your 35cc domes are giving you 195 psi.

 

[Shifty]

Yes, this is an '08, that would make sense. If the base gasket was thinner this could cause it? I wish I would have tested before the head was removed but I dont have a gauge of my own.

 

[YAMA CAT]

Yes, this is an '08, that would make sense. If the base gasket was thinner this could cause it? I wish I would have tested before the head was removed but I dont have a gauge of my own.

Very Pretty! Sound like you maybe running a little race gas until you get another set of domes. :fing02: I bet you are digging that New Ski Smell!

 

[oxnard111]

i earsed some previous messages... i was regurgitating false information.

 

[Shifty]

Thank you, it does have a unique scent to it, most is gone now but the tool kit still has some arroma left. Will I really need to run race gas in this thing? What about avaition fuel? There is a small airport near me, though the manager hates me with a passion. I really need to get another comp tester to check this thing out. I am not sure I am sold on a thinner base gasket giving the high #'s, does anyone know the reason for the 2008's higher compression?

Thanks for the help,

 

[YAMA CAT]

Thank you, it does have a unique scent to it, most is gone now but the tool kit still has some arroma left. Will I really need to run race gas in this thing? What about avaition fuel? There is a small airport near me, though the manager hates me with a passion. I really need to get another comp tester to check this thing out. I am not sure I am sold on a thinner base gasket giving the high #'s, does anyone know the reason for the 2008's higher compression?

Thanks for the help,

I would test your compression again. I just realized you are running a B-pipe Duh. You might be able to get by running 93 if you are not throttle happy, like me. I ran 100 octane for my 701 @ 195 psi because I had a Dry Pipe and was trigger happy.

 

[Shifty]

Well I rented a cheesy compression tester from autozone for piece of mind and I am getting around 175 psi on that junky tester. And I was using the correct addapter (3/4" long threads) Could I have lost compression:ugh:, or could there be a 20psi diff between these compression testers? I am so confused...

 

[YAMA CAT]

Well I rented a cheesy compression tester from autozone for piece of mind and I am getting around 175 psi on that junky tester. And I was using the correct addapter (3/4" long threads) Could I have lost compression:ugh:, or could there be a 20psi diff between these compression testers? I am so confused...

Yes,
I have a crappy tester that gives me ultra low readings like that. We only keep it around to test if we have the same compression in each holes. Our gauge is at least off by 40 psi. A buddy of ours has a good Snap-On that we borrow for a true reading.

 

[cleetus]

Get a snap on gauge, you will need it in the future anyways. And yes avation fuel will raise your octane, I think it is 109??? it burns slower and cooler. Better be safe than sorry

 

[Mark44]

Check your squish.

Mark44

 

[jet pirate]

I did a plug chop and swam it in, keep in mind this was a fresh set of plugs near the end of my first tank. The plugs were mostly white with a little pink to light tan coloration on the side of the tip, the threaded rim of the plug was dry with some black carbon deposits on it.

What does detonation look like?

I am not running this thing all out except for a few short bursts here and there.

detonation will turn your plugs gray. also cranking compression meens next to nothing !! its your compression ratio and squish !!!

 

[Shifty]

I am looking for a snap on gauge on ebay right now, because I always seem to need one. Using solder to check squish (rosin core), what will this tell me? What should I look for? I also have a head from another 62T engine I am going to compare with my SJ's stock one to see if I can tell where the 2008's high compression #'s come from.

What should I look for on my plugs???

 

[jet pirate]

I am looking for a snap on gauge on ebay right now, because I always seem to need one. Using solder to check squish (rosin core), what will this tell me? What should I look for? I also have a head from another 62T engine I am going to compare with my SJ's stock one to see if I can tell where the 2008's high compression #'s come from.

What should I look for on my plugs???

detination will turn your plugs gray !!!