I'm building a Big Cammed 310ci VN Headed 308 and I all ready have a Harrop Highrise Manifold. I was wondering if anyone has compared it to the New Edelbrock Highrise in relation to Top-end Power and better Fuel Distribution,
Harrop Highrise Manifold v Edelbrock Highrise
#1
Posted 29 March 2018 - 07:49 PM
#2
Posted 29 March 2018 - 08:10 PM
In my experience, I would go for a high rise dual plane manifold for the cubes you are playing with. A single plane high rise really is for big cubes and big revs. Probably not the info you exactly wanted but Harrop and Torque Power are the two best VN headed manifolds on the market. I ran 11.5's with 450hp 355 with a dual plane TP manifold. To compare, I ran a 10.9 with a 550hp single plane 355. Same car! Go a dual plane and enjoy the mid range power and pull!
#3
Posted 29 March 2018 - 10:54 PM
I use a harrop on an angry 308, works well makes great power, i def dropped a bit of low to mid power when i switched from a smaller manifold, gearbox ratios have made up for this in my instance.
#4
Posted 30 March 2018 - 12:11 PM
Thanks for those comments, but this is going to be more Drag than Street and with 12:1 Compression and over 650" Lift Cam, it will be Reving! I totally agree with the Dual-Plane Manifolds for a Street Engines. In the late 1990's I went from a Edeldbrock Torker to an Edelbrock Performer and went from 11.8 to 11.6 on a std Stroke 308 with a Trimatic - with the same Engine I changed the Cam to a Crane 288 Copy and went to a Peter Michael's Manifold and ran 11.4/117mph. Work & Life commitments put a halt to further testing, that Engine had 11.2/11.1's in it. My Engine Builder has Flowed both the Harrop & the Edelbrock, with both Manifolds being much the same. The Edelbrock has 'more meat' in the Plenum to allow it to flowed a bit better and it has straighter runners.
#5
Posted 30 March 2018 - 02:36 PM
Go aussiev8 forum may be a review there,only seen dual plane though..most prefer harrop single plane as even with big banger 355 only get a little porting if any...tp single said to be more suited to high revving 383 etc
Used harrop single on 355 10;7cr f280 4500 stally which drove nice on street.
#6
Posted 30 March 2018 - 07:03 PM
I got my info from Jake Edwards (2000hp Torry) from the Nats. He is my tuner and a friend and he reckons the big single plane is better suited to 383's. He said the 355's love a dual plain. But in saying that, I have fitted a high rise single plane Harrop on my 500+hp 355 as it is a 7500 + rpm rever and built for max power.
I just don't think the smaller cubes will benefit from a big single plane. Mild 308's always go better with a Performer than a Torker for example. Ask Struggler...(forum member).
Only my limited knowledge and opinion though but have run plenty of 308 and 355 combos down the strip.
Edited by Redslur, 30 March 2018 - 07:04 PM.
#7
Posted 30 March 2018 - 08:10 PM
My cam runs out at about 6900-7000, i take it to 7200, not the odd traffic light run too, on the circuit.
Still pulls well from about 3500-4000 up.
If its a pure drag engine, prob work fine with the correct stall and diff gears.
#8
Posted 31 March 2018 - 03:45 PM
With large cam(288),high compression & big stally/short gears...mildly ported vn heads & single plane harrop has been done many times.
As long as it's tuned & set up correctly it will be on the wild side yet drivable for a weekender.
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