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AQ290 advice needed

D

dougferony

New member
"Hi there!

I am considering

"Hi there!

I am considering buying a 1987 Carver 270 Montego. I will get a full inspection from a certified surveyor.

Before I take the next step to contact the surveyor, I wanted to know your opinions on this engine and if their are known quirks I should be aware of. I appreciate any advice, raves or concerns about this engine.

Thanks for your time."
 
"The AQ290A is a fantastic eng

"The AQ290A is a fantastic engine. I had one in my 1979 23' Formula until last year. She ran strong for 27 years until the salt water finally rotted out the block. She made her last trip home with two plugs removed blowing water out of the cylinders.

The 290 is a GM350 with a few mods that distinguish it from the AQ260A. The 290 runs a compression ratio of 9:1 as opposed to the 260's 8.5:1. The 290 will rev 5200 rpms whereas the 260 spins 4400.

Basically the 290 was VP's 'hot rod' stock engine squeaking out a few more horses through the higher compression ratio (I believe due to diff. heads). Parts are readily interchangeable between the 200, 225, 260 and 290 and you will find many parts may even be robbed from Merc engines.

The extra hp will allow you to run a slightly larger pitch prop giving you some increased top end performance.

I would never hesitate to buy a boat that has a GM350 powerplant. It is the best engine ever manufactured, in my opinion."
 
"A few extra comments.
The 29

"A few extra comments.
The 290 has 4-bolted main bearing carriers. To really get the power out of the engine, high octane is needed, preferably not less that 97. Another thing is the exhaust. Through transom is a must, the drive exhaust is far to restricted. This engine was intended for those who wanted top end power and willing to do a little extra to get it. For normal cruising, the 260 will give equal power.No need to switch props going from 260 to 290. The allowed rpm increase , 4400 for 260 and 5200 on the 290 takes 'care' of that."
 
New question...

I went and

New question...

I went and physically looked at the engine and I think the spec sheet I saw online was wrong. The engine has model number AQ271C on it and not 290. What is the difference between this and the 290?

Thanks for your continued advice and expertise!
 
"350 Small block Chevy, produc

"350 Small block Chevy, produced from '86-'89. 9.3:1 compression ratio, 4600 rpm max, 275 hp.

Again, the 290 was VP's 'hot rod' engine that, as Morten stated, required the user to do a 'little extra' to scavenge the top end power.

At 275 hp and a 9.3:1 ratio the 271 is still very powerful. Keep in mind both models have the same base block. If the engine is in good shape, I think you will enjoy.

Things you should consider: how well was it maintained, is there a lot of rust, is there sludge on the rockers, how is the compression, etc."
 
"What is the difference betwee

"What is the difference between the A, B and C engines?

Also, this boat has a double prop (one prop placed in front of the other). How does that prop style work and what kind of performance can I expect from it?

Thanks again for all this help!"
 
"In general, the A, B, C denot

"In general, the A, B, C denotes slight changes to the base engine model. For instance, the 271A/B has a compression ratio of 8.5:1, whereas the 271C is 9.3:1. The letters often denote the type of outdrive as well. The 271B came with a 275 drive whereas the 271A and 271C have the 290DP.

The 290DP is a fantastic drive. Very solid. I would be shocked to see anyone post a negative comment about it.

On the 290 drive the props counter rotate. I believe the technology was developed early on for torpedos as a measure to keep them 'tracking' straight. Same can be expected for your boat.

Again, Doug, I would focus on how well the engine has been maintained, more than the specific model number. A GM 350 will not let you down!"
 
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