Reply to "Building a Gr4 replica"

push1267Member

The internals of the motor are all RoushYates spec. It was sold of their nascar program a few years ago when they went from the D3 engines to the newer FR9 engines. This one has done one race since last refresh (400 miles)

It's a nationwide spec. roller engine, compared to the Flat tappet Cup motors. A little less power and torque, around 800 HP and 530-550 Ft-lbs, compared to the Cup motors around 850-870 HP - still (a lot) more than my skills can handle.

I will need to detune a little (I think), probably a less aggressive cam to lower max rpm to around 8000 and maybe thicker headgaskets to lower compression to under the current 12.1.

The block is a 9" deck R451 dry sump with a Bryant crank (3.260 stroke), Plankl rods and Mahle pistons (4.15 bore). Heads are Yates D3s with titanium valves, retainers and locks and jesel valvetrain. Carburator is a Holley 830 nascar.

I'll be taking my chances with the ZF, after all, aren't they supposed to be able to handle 550 Ft-lbs ??

7/19/1712:31 AM

<ul id="{%=id%}ButtonGroup" class="button-group h-popup-buttons even-button-group even-1">
    <li id="{%=id%}Okay_buttonContainer"><a id="{%=id%}Okay" href="javascript:void(0);" class="button success no-margin-bottom h-alert-modal-ok-button" role="button">OK</a><script type="text/javascript">
        (function() {
            function {%=id%}Okay_click(event, data) {
            {%=id%}Popup.hide();
        }
        
                $('#{%=id%}Okay').on('click', {%=id%}Okay_click);
        })();
    </script></li></ul><a href="javascript:void(0);" class="close-reveal-modal" aria-label="Close Modal">&#215;</a><div class="last-modal-focus focus-utility-element" tabindex="0"></div>
</div>
<script type="text/javascript">
        (function() {
            {%=id%}Popup = new SS.Popup.ModalPopup('{%=id%}');
        })();
    </script>

Skip to main content

Membership Required

Remove From Your Block List

Manage Follow Preferences

Block

Please wait...