mercruiser 300 tempest?
 

Can anyone help me find engine specs on the 1986 Mercruiser 300 tempest? I have an 86 model ski centurion 22'10" with the tempest 300. she's tired and needs a rebuild but I would like to know all the info I can before I touch anything.

I can E-mail you the specs if you'd like.

What's your E-mail?

Jeff

I also have a boat with twin tempest 300. Could you please email me the specifications as well?

My email is [email protected]

Have you found out any information about these engines? are they 350s with higher compression?

Thanks,
Jon

They were 9.0:1 compression.I'll scan the sheets and email later today.

Jeff

can I get them too please. I was looking at the original brochure for my Formula 272 LS the standard engines were 260 mercs and bigblocks were not available unless you got the SR1 but 300s were an option. I was wondering if there are any special tempest decals on the valvecovers or spark arrestor. Thanks in advance KZ
[email protected]

Could you also put me on the e-mail list?
jay21one @ yahoo . com


Yes they had a spark arrestor that said 300 Tempest on it. and I think a 300 decal on the valve covers.

I must apologize, I've been quite busy.
Tomorrow I will get to it!

Jeff

I would love to have some pics of the engine / decals:p:p:p

Jeff thanks for the spec sheets.
ERIKV79 AND OLMAKO20 Can one of you guys to check some casting #s. I can break down all the details for you. First I need the casting # on the back of the engine block It will be at the rear of the engine behind the distributor where the bellhousing bolts to the engine block on top left or right. Next I need the casting # under the rocker arm cover it will be between the valves. an example of the engine block # is this (14010209) An example of the cyl. head # is this (3998997) I have been told that mercruiser took the L-82 Corvette engine and made a marine version out of it. This is how I can confirm it for you. From Jeffs spec sheets we know You have a forged steel crankshaft Forged aluminum pistons special camshaft and valve springs and a 4 bolt main block. Highrise aluminum intake manifold These are the best parts GM had to offer for durability. The main thing to take from this is If you replaced the engines with run af the mill rebuilts these parts most likely wont be in them. If they are just tired with alot of hours rebuilding the motor you have is the best bet. I have all the GM books and can confirm it thru the #s. Thanks Paul. PS If we get some tempest engine decal pics maybe we can get repros made.

Sorry guys Ive been away for a bit. Yes I have the arrester cover intact and will post some pics a.s.a.p. I will also get the casting #s up as well. I too have heard the Corvette story and I know that you can buy a mercruiser intake plug from Corvette Central.

Here is the arrester cover. Ill need to take some things apart to get the casting numbers but Ill post them by saturday. Could I please get the info sent to me? [email protected].

http://i978.photobucket.com/albums/a...Picture637.jpg

Very cool, the 320EFI was around the same time as well. I think that was a 350 too.

Have to check in on this one, my 22 Classic had a T300 also. I sold the engine to a buddy who stuffed it into an 18 Donzi. That engine was from what I have been able to glean over time was 300 at the prop, makes sense as it was a tad faster then the 454 330 hp BB. It has one of the nicest sounding cams!

Phil

erik any chance you can send me the specs? I know this thread is a bit old......hoping your still hanging around the forum

Will this do ???

Love the "must be used with leaded gas"

Interesting drive in the pic. It's an Alpha SS, but it has side water inlets instead of the two inlet above the nose.

alpha ss tempest 300
 

I have this package in my 1987 Kavalk 19 Does easy 71 to 73 GPS. Thinking of selling and going slower. It is mint so what is it worth?

Any pictures?

300 Tempest specs
 

I am in the process of rebuilding my 1986 300 Tempest. Can you please email me the spec sheet as well? Thank you [email protected]

I had the 320temptest with the alpha ss in a donzi minx blue and honey was a great combo

I had a pair of the 350's in an IMP 255 (Magnum splash). X was too high and the thing was a scary, chine dancing, mad boat, but boy was she fun. https://ziq2cw.blu.livefilestore.com...ad3.jpg?psid=1

basically it was forged crank forged flat top pistons. there are way better cams and heads out there than what was used in the tempest. heck, add another few hp, it'll be a GTO...

Mercury 300 Tempest
 

Jeff,
Hi there
I know this is old but I would love to get the specs for the Mercury 300 Tempest. Also if you know the GM manifold and carb numbers that would be terrific. Building one up and sure need the info on it.
my email is [email protected]
Thanks
Bill

Hey, I am an auto parts seller. My passion is off shore boat racing. I am looking after old Mercruiser Alpha "SS" Outdrive Lower Unit.

I Think the 300 may be HP, I don't think it is 300 CI, I have never heard of a 300 CI. (But I could be Wrong)
The 300 HP is what it seems to be but wondering what cubic inch motor it was? Now remember it was supposedly in a 1967 boat. What would they have put into a 67 v-drive. I have always heard of the 427 fords with 400 hp but what would be the lesser hp for the v-drive in 1967? It could be that this guy was mistaken and he has a 289 ford block with his v-drive. I do remember seeing a couple from Jacksonville that had a nice white with red stripe v-drive barrel back. I believe it had a 289 in it. Thanks, Tom

Mercury 300 Tempest
 

Tom, Thanks
Yelp it is a 350ci at 300hp made by Mercury. I scored a manual for it online. I bought one of the 320hp EFI engines with a couple of hours on it but no one knows that EFI system and there are not many parts for it so I am turning it into a 300hp Tempest. They had the same four bolt main bearings, same rotating assemblies with forged crank rods and pistons and a bit of a nice cam. The tempest came with the high rise dual plan manifold but due to height limits I went with a standard GM rodgester manifold and old school Quadrajet carb.
Thanks
Bill

300 tempest
 

You still got the 320 efi did you end up switching it over to a 300 tempest? Shoot me a call bill 734 752 1271 I would like to buy

325 efi
 

Hi there,
Yes i still have the complete system and was thinking about listing it.
Thanks
Bill

320efi
 

Hey Bill you have the whole long block? For the 320efi or the 300 tempest if can give me a call 734 752 1271

325 long block
 

Sorry I used the engine assembly to build the tempest copy. I have all the fuel injection parts including the harness. They are all almost new may be a couple hours but I could not find any support or controller for that system. Thats why I went with to old Quadrujet slupper but I can fix it easy and I tottally rebuit it icluding throttle shaft bushing so should be good for a while. If you know anyone running the old 325 EFI system i would make a deal on the parts.

320efi
 

Yes I am running twin 320efis in my 272 sr1 contact me at 734 752 1271 I would be interested in purchasing