Marine L-88 Engine w/ Cast Iron Heads

[SuperNovaSS]

I picked up an engine yesterday and thought I would share. It is a complete L-88 engine that was built by GM with cast iron heads. The cast head L88 is a subject I have always been interested in. I have seen a few pop up over the years and mos message boards seem to dismiss the engines as being home built or L71/L72 engines with a 3933198 intake added.

This engine was removed from a 1969 speedboat and was the original engine to the boat. It was running 2 days ago. The suffix code is 7BL. I have seen this suffix before and always wondered what it was. The engine has the correct 3933198 intake, 840 heads, heavy duty AC fuel pump, 7/16 dimple rods, and the 7115 steel crank.

[SuperNovaSS]

Here is the engine as it was pulled. The carb is a 3246 service dated Holley. I have seen 3246 carbs on most marine 427s. The pulleys are GM units but are not deep groove.

http://i179.photobucket.com/albums/w301/super-novass/MarineL-88/Complete1Small.jpg

http://i179.photobucket.com/albums/w301/super-novass/MarineL-88/Complete2Small.jpg

[SuperNovaSS]

The block is a 3963512 casting with a casting date of B 5 9.

http://i179.photobucket.com/albums/w301/super-novass/MarineL-88/CastingNumberSmall.jpg

http://i179.photobucket.com/albums/w301/super-novass/MarineL-88/CastingDateSmall.jpg

The heads are both 3919840 with casting dates of A209 and C139.

http://i179.photobucket.com/albums/w301/super-novass/MarineL-88/840HeadCastingSmall.jpg

http://i179.photobucket.com/albums/w301/super-novass/MarineL-88/HeadDate1Small.jpg


http://i179.photobucket.com/albums/w301/super-novass/MarineL-88/HeadDate2Small.jpg

[SuperNovaSS]

The front pad is stamped TO3177BL. The 7BL suffix must mean closed chamber L-88 with cast iron heads.

http://i179.photobucket.com/albums/w301/super-novass/MarineL-88/SuffixSmall.jpg

The 3933198 intake is dated 9.18.68. I believe the 198 intakes were only made in certain runs. I don't think I have ever seen a casting date from October 68-Feb 69 unless the 198 was hand stamped.

http://i179.photobucket.com/albums/w301/super-novass/MarineL-88/IntakeSmall.jpg

http://i179.photobucket.com/albums/w301/super-novass/MarineL-88/IntakeDateSmall.jpg

[SuperNovaSS]

Factory high lift rockers are still intact.

http://i179.photobucket.com/albums/w301/super-novass/MarineL-88/RockerSmall.jpg

L88 pushrods still there

http://i179.photobucket.com/albums/w301/super-novass/MarineL-88/ValleySmall.jpg

[SuperNovaSS]

Cool original fuel pump

http://i179.photobucket.com/albums/w301/super-novass/MarineL-88/FuelPumpSmall.jpg

http://i179.photobucket.com/albums/w301/super-novass/MarineL-88/FuelPumpDateSmall.jpg

[SuperNovaSS]

Pulling the pan was exciting. No denying this is a L-88

http://i179.photobucket.com/albums/w301/super-novass/MarineL-88/RotatingAssemblySmall.jpg

http://i179.photobucket.com/albums/w301/super-novass/MarineL-88/DimpleRodsSmall.jpg

http://i179.photobucket.com/albums/w301/super-novass/MarineL-88/7115CrankSmall.jpg

[SuperNovaSS]

I decided not to pull the heads since the engine runs great and I can see it is standard bore due to the TRW pistons having GM and the part number on the undersides.

[smallblockhero]

neat find. im really surprisd at the carb. most OE marine carbs have 180 degree vents. having worked at a boat dealer ive never seen one like that factory.

we had at least 4 early 70's BB chevys and fords and the carbs all looked like this

http://www.michiganmotorz.com/images/holley4150_LG001.jpg

[olredalert]

----Since the carb is service dated I would guess that the owner or mechanic bought an automotive carb when the boat carb went bad. It was probably cost effective at the time, but not too safe......Bill S

[SuperNovaSS]

I doubt it. I have had 3 marine big blocks and all 3 had 4346 carbs. I have read about others online that also had the 4346. Maybe this is before the Coast Guard required the curved bowl vents on marine applications? I wish is was a 4296 carb with a Fed or March date like the engine <<GRAEMLIN_URL>>/smile.gif

[SuperNovaSS]

Here's another that had the 4346:

http://forums.corvetteforum.com/c3-tech-...te-running.html (http://forums.corvetteforum.com/c3-tech-performance/1521831-1969-427-iron-headed-bbc-3955270-complete-running.html)

[Fast67VelleN2O]

3246 or 4346?

[SuperNovaSS]

OOOPS, 3246. My mind must have been elsewhere.

[SuperNovaSS]

http://i179.photobucket.com/albums/w301/super-novass/3246CarbSmall.jpg

[Smokey]

So how did the boat scoot across the water? Thats the important question. Could you keep your foot in it? <<GRAEMLIN_URL>>/smile.gif

[John]

...How can a marine motor be identified.... from a car motor?
What are the signs? <<GRAEMLIN_URL>>/dunno.gif

[SuperNovaSS]

I bought the engine out of the boat but never rode in the boat. It was supposed to go 60MPH. Seems pretty fast for on the water.


Jason

[SuperNovaSS]

Many times marine motors have the plugs taken out of the front of the heads for water ports. Also, the exhaust threads are usually studded for the manifolds.


Jason

[SuperNovaSS]

Has anyone ever seen the M/T finned covers with no logo like these ones?


Jason

[Fast67VelleN2O]

I've seen them. They are very early. 1965-1966. Small block covers are the same way. They may have gone on a few more years but not sure.

-Matt

[SuperNovaSS]

Thanks Matt


Jason