HP525 EFI Dyno Numbers
 

Does anyone have the peak torque and horsepower numbers from a dynoed HP525EFI? Those numbers and their related rpm's would be of interest to me and others on this board.
I know John B asked for the cam specs, some time ago, for this motor but according to his post, never received that information.
Is that information available?
Thanks in advance for any replies.
Russ

Re: HP525 EFI Dyno Numbers
 

I read on here that the 525EFI were dyno at 540-545HP. This came from Dustain (whipple). I also read in a mag that the torque was in the mid 500.

Re: HP525 EFI Dyno Numbers
 

I was told by Innovation Marine that peak hp is at 5380, just before the rev limiter. I would estimate peak torque to be in the low to mid 4000 range.

Matt

Re: HP525 EFI Dyno Numbers
 

Matt,
The numbers you posted definitely make sense and do not attribute to the "torque loading" of the drive.
Now, I would like to see the cam specs on this engine.
Russ

Re: HP525 EFI Dyno Numbers
 

Russ,
The cam for the 525 EFI is
Crane 16HR00004 BBC Hydraulic Roller
Duration (advertised) - 298/306
Duration (@ 0.050) - 236/244
Lift - .610 Intake, .632 Exhaust
Lobe Center - 114°
There are multiple factors at work in this application that determine the relation to duration and TQ/HP peak.
Bob

Re: HP525 EFI Dyno Numbers
 

Rmbuilder Has Always Got The Cam Info Down.i Have Dynoed 525efis And Have Had As Much As 560hp Right At The Rev Limit And As Much As 540 Ft Lbs Of Torque And Have Checked These Numbers With A Friend At Inovation That Runs A Dyno Room There And The Numbers Match . Generally They Are Anywhere From 535 Hp To 560 Even 565 On The Real Good Ones. Sincerely Laz Mesa

Re: HP525 EFI Dyno Numbers
 

Hey Bob and Lazaro:

I have a couple questions about this engine too. Is this cam the same as the 741 or are there important differences? And what do you think would be the result if the runners were lengthened 1-1.5"?

Tom

Re: HP525 EFI Dyno Numbers
 

Tom,
Not the same cam. The 525efi has:
2* more duration I/E @ .004 and .050
114*LSA vs 112* LSA
109*/119* ICL/ECL vs 107*/117* ICL/ECL
74* vs 76* overlap
Great points of discussion, runner length and torque/HP curve placement,fuel injection vs carb (single plane vs dual plane),intake cross section, duration and cylinder head flow. There is a significant difference in how this cam will perform (and the cam requirements) with the Edelbrock heads and FI as compared to say a single plane carb motor with ported AFRs. It can alter the peaks 500+ rpm.
139741
Cam Timing: TAPPET @.050 Lift:
Opens Closes Max Lift Duration
Intake 10 BTDC 44 ABDC 107 234 °
Exhaust 58 BBDC 4 ATDC 117 242 °
16HR00004
Cam Timing: Tappet @ .050 Lift
Opens Closes Max Lift Duration
Intake 9.0 BTDC 47.0 ABDC 109 °ATDC 236 °
Exhaust 61.0 BBDC 3.0 ATDC 119 °BTDC 244 °
Bob

Re: HP525 EFI Dyno Numbers
 

Tom There Are Many Variables Generlly Speaking Lengthen The Runner And The Max Hp Number Will Most Likely Come Down Slightly And Also Lower In The Rpm Range And The Torque Will Most Likely Increase Throught The Rpm Range.sincerely Laz Mesa

Re: HP525 EFI Dyno Numbers
 

1.1HP/CID not too bad from the big Merc. Blue. Does anyone have a HP and TQ printout?

Re: HP525 EFI Dyno Numbers
 

It's the same as my 741 cam except for the LSA 112 vs 114 :)
The Gen VI 741 cams (168741) have the same duration and lift 236/244 .610/.632 as the cam in the 525. With the 525 obviously being a Gen VI they've just spread the centers a bit on the 741 Gen VI cam.
The Gen IV stuff has less duration all be it slightly.
Dave

Re: HP525 EFI Dyno Numbers
 

Does anyone know exactly what edlebrock head is on the 525?

Re: HP525 EFI Dyno Numbers
 

ttt

Re: HP525 EFI Dyno Numbers
 

Wags,
A phone call to Innovation might get you an answer.
Russ

Re: HP525 EFI Dyno Numbers
 

The same Edelbrock marine head that you can buy from Summit.
Rectangular port, anodized with inconel exhaust valves.
(#61559) Does not come with springs, studs, etc. Just valves and seals.
Good head but a bit thin decked for blower apps from my experience.

Re: HP525 EFI Dyno Numbers
 

Experience is a *****. :rolleyes: How's it going Dave?

Re: HP525 EFI Dyno Numbers
 

Hey Tom,
Experience seems to help everyone else but the victim :drink: :D
Later,
Dave

Re: HP525 EFI Dyno Numbers
 

I thought it was the Edelbrock oval port head. 290cc on the 525

Re: HP525 EFI Dyno Numbers
 

It may be...
I was just assuming that with the chambers being 110cc on the ovals and 118cc on the rectangular the compression ratio would work out to the specified 8.75:1 on the rectangulars. That and I didn't think Merc would want to re-tool the intake :)
Could be wrong...anybody know for sure? They're probably too new for anyone to be tearing them down yet :rolleyes:

Re: HP525 EFI Dyno Numbers
 

The heads are made especially for Mercury. They even have "Mercury" casted on them. The exhaust bolt pattern is slightly different from a "standard" BBC head.

Re: HP525 EFI Dyno Numbers
 

Just curious, why would the exhaust bolt pattern be different. You mean you cant use standard CMIs, IMCO, etc? If you mean they moved the whole pattern then they also moved the port.
I would be all for that because a few years back I spent three weeks discussing this with Edelbrock engineers convincing them that some marine exhuast manifolds (i.e. Stainless Marine) would not properly fit their heads due to interference issues. They ended up paying me for custom adapters. Great guys to work with BTW. Moving the port would change the flow characteristics of the head however.

Also, Edelbrock cast the the heads for GM Perf and have the GM logo on them. I'm still thinking they are basically the same overall casting.

Re: HP525 EFI Dyno Numbers
 

Although I have not taken any measurements, I have heard that a standard set of BBC exhaust manifolds/headers will not directly bolt on these heads.

Re: HP525 EFI Dyno Numbers
 

There was a set for sale on e-bay (it might have been somewhere else)a few days ago w/the mercury logo cast in them,i'll do a search and see if they are still kicking around, from the pics we could see if they are ovals or rectangle port,Smitty
Here is the pic off e-bay,i found it under "mercury racing" BUT they don't say in add exactlt what engine these go to but they are rect port,hard anodized,they have mercury racing cast in them AND the bid on them is only 850 w/just over 24 hours left on auction if someones interested!

Re: HP525 EFI Dyno Numbers
 

The heads are custom made for Merc. The headers do have a different bolt pattern than the other BBC.