Power options for older Glastron

I have a 1974 Glastron in very good shape that I am updating the engine on. It had a 302 Ford V-8 with 351 heads (factory stock). Attached pictures show old Ford 302 and Mercruiser EFI components, and the new explorer engine. I am putting in a new explorer 302 engine. The engine is a long block including water pump, lower efi manifold, valve covers, oil pan, etc.

I would like to upgrade the fuel system. I thought about putting in efi and picked up a Mercruiser efi system but it looks quite complicated. Is this feasible or would I be better off with a good carburetion setup.

Right now it has a Holley 450 CFM carburetor.

I would like recommendations on completing my project

Thanks,

Jim

 

If the engine came out of an Ford Explorer, you'll need to at least change the camshaft ot it will disapoint you. The low end torque will be poor for the application.

 

Camshaft for Explorer

I thought the cam might be a problem. Do you have any suggestions for brand name? I picked up some roller tappets to go with it.

Thanks,

Jim

 

The Stock Ford Roller cam used in 95 -2000 Explorers (pt no. F4TE-6250-BA)is a GREAT TORQUE cam for marine use. Used in a Stock 302 marine(5.0) with stock center rise exhaust manifolds, torque will be 300 lb-ft @ 2000 rpm to a max of 340 around 3500 rpm.

Unless the engine is highly modified for sustained use over 5000 rpm, this is the cam to use.

 

This engine is a crate engine so I assume it would have the stock cam.

I am trying to fit it with fuel injection and so have acquired most of the components for a 1993 OMC efi including fuel rails, ecu, wiring harness, low pressure pump, and throttle body. I am missing the upper manifold and the high pressure pump. From what I have found out so far there was a water cooled reservoir/high pressure pump setup that was subsequently replaced by a water cooled fuel heat exchanger. I have a good EFI OMC manual but there is still a lot left out.

Thanks,

Jim Marshall

 

If it is truly a late model Explorer Crate Engine and it has a roller cam, most likely it will have the "High Torque Explorer cam".

Can't help you much with the Fuel injection other than, the Standard Explorer system is Equiv. to a 500 cfm. carb.

Good luck on your project. Jango

 

Thanks for the help. I think that it is. It has GT40 heads and everything is brand new (not a rebuild). Do you know what the HP is on the explorer engine? I realize that torque is the number one thing in boats but I am curious for comparison to my older 200 hp non-roller carbureted 302.

Jim

 

I believe the 302HO Explorer Engine was rated at 210HP (single Exhaust & mufflers). For marine use, with center rise exhaust manifolds it should be at least 10% Higher, 230HP plus. I don't believe GT40 heads were Std and will add another 5 - 10%.

Keep in mind, Speed predictions based on HP change is expodential. A 25% increase in HP is only good for a 12% increase in speed. (everything else being equal - weight etc.)

 

Jango,

I guess what my goal is what is called "retro-mod" or bringing an older unit more up to date. I like the idea of fuel injection, roller camshaft, and other improvements. I don't need a great deal of improvements because I was satisfied with the boat before.

In comparison of the exhaust ports on the newer heads they are a fair amount bigger.

You mentioned the center rise exhaust manifolds. Have you or anyone seen manifolds like the Glastron ones pictured and have any idea how these would behave?

Thanks,


Jim

 

The Glastron manifolds are very similar to the Mercruiser Log Type. Not as efficient as the center rise type, but "Usable". If your manifold has enough material around the Individual exhaust ports, It would be a good idea to grind material and try to "match" the Head ports, thereby minimizing exhaust reversion. Left "As is" the manifolds will tend to "choke" the motor resulting in loss of power at the very least.

 

Thanks for the information. Would you recommend any brand of replacements? I see quite a few listed on ebay, etc.

Jim

 

I'm told these are Good, but not sure if price is for one side or the pair. They will however require extensive plumbing changes.

Ebay# 310006333001

Since you are more interested in a "Resto-Mod" and not max. performance, I would stay with your Glastron manifolds after "Opening up" the exhaust ports as much as posible. If you are unable to Fully open, taper the opening for a 1/4 in. or so to the Head Port size.

Hope this helps, Jango

 

I will do that. I have a die grinder and will work off the manifold gasket and see what I can do from there.

Thanks,

Jim

 

Jango: I am curious about the specs of the Explorer camshaft. Did they install the "tow truck" package type? That is about identical with the marine version.

 

Resto-Mod Explorer/Glastron/Volvo Penta

I have looked high and low on the internet to try to find out more about the specifications of the Explorer 5.0 engine. It would be nice to know things like the torque curves, injector size, throttle body size, etc.

Jim